2019 |
Wang, Y; Slassi, A; Cornil, J; Beljonne, D; Samorì, P Tuning the Optical and Electrical Properties of Few‐Layer Black Phosphorus via Physisorption of Small Solvent Molecules Article de journal Dans: Small, 15 , p. 1903432, 2019. @article{Wang2019b, title = {Tuning the Optical and Electrical Properties of Few‐Layer Black Phosphorus via Physisorption of Small Solvent Molecules}, author = {Y. Wang and A. Slassi and J. Cornil and D. Beljonne and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smll.201903432}, year = {2019}, date = {2019-11-20}, journal = {Small}, volume = {15}, pages = {1903432}, abstract = {Black phosphorus (BP) is recently becoming more and more popular among semiconducting 2D materials for (opto)electronic applications. The controlled physisorption of molecules on the BP surface is a viable approach to modulate its optical and electronic properties. Solvents consisting of small molecules are often used for washing 2D materials or as liquid media for their chemical functionalization with larger molecules, disregarding their ability to change the opto‐electronic properties of BP. Herein, it is shown that the opto‐electronic properties of mechanically exfoliated few‐layer BP are altered when physically interacting with common solvents. Significantly, charge transport analysis in field‐effect transistors reveals that physisorbed solvent molecules induce a modulation of the charge carrier density which can be as high as 1012 cm−2 in BP, i.e., comparable to common dopants such as F4‐TCNQ and MoO3. By combining experimental evidences with density functional theory calculations, it is confirmed that BP doping by solvent molecules not only depends on charge transfer, but is also influenced by molecular dipole. The results clearly demonstrate how an exquisite tuning of the opto‐electronic properties of few‐layer BP can be achieved through physisorption of small solvent molecules. Such findings are of interest both for fundamental studies and more technological applications in opto‐electronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Black phosphorus (BP) is recently becoming more and more popular among semiconducting 2D materials for (opto)electronic applications. The controlled physisorption of molecules on the BP surface is a viable approach to modulate its optical and electronic properties. Solvents consisting of small molecules are often used for washing 2D materials or as liquid media for their chemical functionalization with larger molecules, disregarding their ability to change the opto‐electronic properties of BP. Herein, it is shown that the opto‐electronic properties of mechanically exfoliated few‐layer BP are altered when physically interacting with common solvents. Significantly, charge transport analysis in field‐effect transistors reveals that physisorbed solvent molecules induce a modulation of the charge carrier density which can be as high as 1012 cm−2 in BP, i.e., comparable to common dopants such as F4‐TCNQ and MoO3. By combining experimental evidences with density functional theory calculations, it is confirmed that BP doping by solvent molecules not only depends on charge transfer, but is also influenced by molecular dipole. The results clearly demonstrate how an exquisite tuning of the opto‐electronic properties of few‐layer BP can be achieved through physisorption of small solvent molecules. Such findings are of interest both for fundamental studies and more technological applications in opto‐electronics. |
Lucas, S; Leydecker, T; Samorì, P; Mena-Osteritz, E; Bäuerle, P Covalently linked donor–acceptor dyad for efficient single material organic solar cells Article de journal Dans: Chem. Commun, 55 , p. 14202–14205, 2019. @article{Lucas2019, title = {Covalently linked donor–acceptor dyad for efficient single material organic solar cells}, author = {S. Lucas and T. Leydecker and P. Samorì and E. Mena-Osteritz and P. Bäuerle}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/c9cc07179b}, year = {2019}, date = {2019-11-04}, journal = {Chem. Commun}, volume = {55}, pages = {14202–14205}, abstract = {A novel covalently linked donor–acceptor dyad comprising a dithienopyrrol-based oligomeric donor and a fullerene acceptor was synthesized and characterized. The concomitant effect of favorable optoelectronic properties, energy levels of the frontier orbitals, and ambipolar charge transport enabled the application of the dyad in simplified solution-processed single material organic solar cells reaching a power conversion efficiency of 3.4%. }, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel covalently linked donor–acceptor dyad comprising a dithienopyrrol-based oligomeric donor and a fullerene acceptor was synthesized and characterized. The concomitant effect of favorable optoelectronic properties, energy levels of the frontier orbitals, and ambipolar charge transport enabled the application of the dyad in simplified solution-processed single material organic solar cells reaching a power conversion efficiency of 3.4%. |
Samorì, P; Giuseppone, N From Supramolecular Chemistry to Complex Chemical Systems Article de journal Dans: Chem. Eur. J, 25 , p. 13229–13230, 2019. @article{Samorì2019b, title = {From Supramolecular Chemistry to Complex Chemical Systems}, author = {P. Samorì and N. Giuseppone}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/chem.201904385}, year = {2019}, date = {2019-09-27}, journal = {Chem. Eur. J}, volume = {25}, pages = {13229–13230}, abstract = {Happy Birthday! In their editorial, Paolo Samorì and Nicolas Giuseppone introduce our Virtual Collection honoring Professor Jean‐Marie Lehn on the occasion of his 80th birthday. This anniversary represents just an excellent excuse to celebrate a most remarkable chemist who has always been far ahead of his time, thanks to a unique combination of scientific visions, creativity, breadth, drive, and dedication. image It is our greatest pleasure to introduce this Virtual Collection honoring Professor Jean‐Marie Lehn on the occasion of his 80th birthday. This anniversary represents just an excellent excuse to celebrate a most remarkable chemist who has always been far ahead of his time, thanks to a unique combination of scientific visions, creativity, breadth, drive, and dedication. During the last 55 years, he has shaped his field of research and he has been a major source of inspiration for several generations of researchers in chemistry, and sometimes beyond chemistry. We could not see entire parts of biology and materials science as we see them today without knowing what supramolecular chemistry has taught us. Jean‐Marie Lehn has also been a most successful mentor who trained more than 400 students and collaborators over the years in his laboratory, always with a real human touch in all his interpersonal interactions. Over 100 of them are today professors in the most important universities and research centers worldwide, many others are leaders in industry, and one of them even received the Nobel Prize (see Figure 1). image Figure 1 Open in figure viewerPowerPoint Jean‐Marie Lehn (Nobel Prize 1987) together with the recipients of the 2016 Nobel Prize for Chemistry, Jean‐Pierre Sauvage, Sir Fraser Stoddart, and Ben Feringa, during the Ceremony in Stockholm on December 10th, 2016. Supramolecular chemistry concepts have been instrumental in the design and synthesis of artificial molecular machines. ©Nobel Media AB. Photo: Alexander Mahmoud. The Nobel Foundation is gratefully acknowledged for allowing the publication of this photo. Jean‐Marie Lehn is in formal records an Alsatian, strongly attached to his roots, but he can also be firmly described as a true European citizen. He has always been a greatest supporter of Europe, and not surprisingly, together with Peter Gölitz, he founded “Chemistry – A European Journal” in 1995. This has been only one of the many joint initiatives he has co‐directed with Wiley‐VCH. He has been Board Chair of Chemistry ‐A European Journal until 2003 and on the International Advisory Board of Angewandte Chemie for over 20 years. He has supported the launch of the open access journal ChemistryOpen, for which he currently serves as Board Chair, and was founding Co‐Chair of the Editorial Advisory Board of ChemBioChem. Following a PhD in Chemistry at the University of Strasbourg under the supervision of Prof. Guy Ourisson, former President of the French Academy of Sciences, and a Post Doc at Harvard University with legendary Prof. Robert Burns Woodward working on Vitamin B12, Jean‐Marie Lehn has been Professor at the University of Strasbourg since 1966. In 1980, he took the Chair of Chemistry of Molecular Interactions at the Collège de France in Paris and was awarded the Nobel Prize for Chemistry in 1987, together with Charles J. Pedersen and Donald J. Cram. Jean‐Marie Lehn is a true innovator who opened numerous new fields of research. Whereas chemistry had been historically considered to rely on the use of covalent bonds to generate isolated molecules with intrinsic physical and chemical properties, the major revolution steered by Professor Lehn has been based on the use of noncovalent interactions to create well‐defined multicomponent architectures: this is the essence of supramolecular chemistry. A major strength of his scientific approach has always been to precisely demonstrate with rigorous methodologies and simple examples new notions, and to put these notions in much broader perspectives – often inspired by philosophy and arts – to generate paradigms of deep impact. From early works dedicated to the selective complexation between a single host molecule and a single guest molecule, he rapidly moved to the extension of supramolecular chemistry towards larger supramolecular assemblies and to their emerging functions as self‐assembled systems. In parallel, he demonstrated by a series of striking examples how such entities can be encoded at the molecular level to make their supramolecular structures precisely programmable and reconfigurable, in order to design stimuli‐responsive systems with specific properties and capable of performing well‐defined tasks. A direct consequence of these approaches resulted in his pioneering works in dynamic combinatorial chemistry, a domain merging the reversible nature of supramolecular bonds with combinatorial chemistry, in order to spontaneously generate well‐defined chemical entities from large libraries of constituents. Altogether, this string of endeavors strongly impacted the birth of what we consider nowadays as the chemistry of complex systems, a domain which is of crucial importance to understand very fundamental questions, such as the functioning of living systems, and to drive new technologies in sectors of major societal relevance such as medicine, information technology, and environment. Jean‐Marie Lehn has been overall a real driving force, seeding and catalyzing intellectual advances in fundamental science and processes of innovation in industry: a true gift for chemistry and for science. This interdisciplinary research was given a home in 2002 when Jean‐Marie Lehn founded the Institut de Science et d′Ingénierie Supramoléculaires (ISIS), a truly cross‐disciplinary institute of the University of Strasbourg and CNRS where chemistry is carried out at its interface with physics and biology, in a unique environment where academic and industrial satellite labs are intertwined. We are most grateful to Wiley, in particular to Neville Compton, Haymo Ross, Francesca Novara, and Diane Smith for shaping up this virtual issue combining some papers of Jean‐Marie Lehn with some of his former students and close collaborators. Although it represents just the “tip of the iceberg”, it already provides ample evidence of the central and instrumental role played by a unique and extremely inspiring scientist who is key to the past, present, and future of chemistry and certainly beyond! }, keywords = {}, pubstate = {published}, tppubtype = {article} } Happy Birthday! In their editorial, Paolo Samorì and Nicolas Giuseppone introduce our Virtual Collection honoring Professor Jean‐Marie Lehn on the occasion of his 80th birthday. This anniversary represents just an excellent excuse to celebrate a most remarkable chemist who has always been far ahead of his time, thanks to a unique combination of scientific visions, creativity, breadth, drive, and dedication. image It is our greatest pleasure to introduce this Virtual Collection honoring Professor Jean‐Marie Lehn on the occasion of his 80th birthday. This anniversary represents just an excellent excuse to celebrate a most remarkable chemist who has always been far ahead of his time, thanks to a unique combination of scientific visions, creativity, breadth, drive, and dedication. During the last 55 years, he has shaped his field of research and he has been a major source of inspiration for several generations of researchers in chemistry, and sometimes beyond chemistry. We could not see entire parts of biology and materials science as we see them today without knowing what supramolecular chemistry has taught us. Jean‐Marie Lehn has also been a most successful mentor who trained more than 400 students and collaborators over the years in his laboratory, always with a real human touch in all his interpersonal interactions. Over 100 of them are today professors in the most important universities and research centers worldwide, many others are leaders in industry, and one of them even received the Nobel Prize (see Figure 1). image Figure 1 Open in figure viewerPowerPoint Jean‐Marie Lehn (Nobel Prize 1987) together with the recipients of the 2016 Nobel Prize for Chemistry, Jean‐Pierre Sauvage, Sir Fraser Stoddart, and Ben Feringa, during the Ceremony in Stockholm on December 10th, 2016. Supramolecular chemistry concepts have been instrumental in the design and synthesis of artificial molecular machines. ©Nobel Media AB. Photo: Alexander Mahmoud. The Nobel Foundation is gratefully acknowledged for allowing the publication of this photo. Jean‐Marie Lehn is in formal records an Alsatian, strongly attached to his roots, but he can also be firmly described as a true European citizen. He has always been a greatest supporter of Europe, and not surprisingly, together with Peter Gölitz, he founded “Chemistry – A European Journal” in 1995. This has been only one of the many joint initiatives he has co‐directed with Wiley‐VCH. He has been Board Chair of Chemistry ‐A European Journal until 2003 and on the International Advisory Board of Angewandte Chemie for over 20 years. He has supported the launch of the open access journal ChemistryOpen, for which he currently serves as Board Chair, and was founding Co‐Chair of the Editorial Advisory Board of ChemBioChem. Following a PhD in Chemistry at the University of Strasbourg under the supervision of Prof. Guy Ourisson, former President of the French Academy of Sciences, and a Post Doc at Harvard University with legendary Prof. Robert Burns Woodward working on Vitamin B12, Jean‐Marie Lehn has been Professor at the University of Strasbourg since 1966. In 1980, he took the Chair of Chemistry of Molecular Interactions at the Collège de France in Paris and was awarded the Nobel Prize for Chemistry in 1987, together with Charles J. Pedersen and Donald J. Cram. Jean‐Marie Lehn is a true innovator who opened numerous new fields of research. Whereas chemistry had been historically considered to rely on the use of covalent bonds to generate isolated molecules with intrinsic physical and chemical properties, the major revolution steered by Professor Lehn has been based on the use of noncovalent interactions to create well‐defined multicomponent architectures: this is the essence of supramolecular chemistry. A major strength of his scientific approach has always been to precisely demonstrate with rigorous methodologies and simple examples new notions, and to put these notions in much broader perspectives – often inspired by philosophy and arts – to generate paradigms of deep impact. From early works dedicated to the selective complexation between a single host molecule and a single guest molecule, he rapidly moved to the extension of supramolecular chemistry towards larger supramolecular assemblies and to their emerging functions as self‐assembled systems. In parallel, he demonstrated by a series of striking examples how such entities can be encoded at the molecular level to make their supramolecular structures precisely programmable and reconfigurable, in order to design stimuli‐responsive systems with specific properties and capable of performing well‐defined tasks. A direct consequence of these approaches resulted in his pioneering works in dynamic combinatorial chemistry, a domain merging the reversible nature of supramolecular bonds with combinatorial chemistry, in order to spontaneously generate well‐defined chemical entities from large libraries of constituents. Altogether, this string of endeavors strongly impacted the birth of what we consider nowadays as the chemistry of complex systems, a domain which is of crucial importance to understand very fundamental questions, such as the functioning of living systems, and to drive new technologies in sectors of major societal relevance such as medicine, information technology, and environment. Jean‐Marie Lehn has been overall a real driving force, seeding and catalyzing intellectual advances in fundamental science and processes of innovation in industry: a true gift for chemistry and for science. This interdisciplinary research was given a home in 2002 when Jean‐Marie Lehn founded the Institut de Science et d′Ingénierie Supramoléculaires (ISIS), a truly cross‐disciplinary institute of the University of Strasbourg and CNRS where chemistry is carried out at its interface with physics and biology, in a unique environment where academic and industrial satellite labs are intertwined. We are most grateful to Wiley, in particular to Neville Compton, Haymo Ross, Francesca Novara, and Diane Smith for shaping up this virtual issue combining some papers of Jean‐Marie Lehn with some of his former students and close collaborators. Although it represents just the “tip of the iceberg”, it already provides ample evidence of the central and instrumental role played by a unique and extremely inspiring scientist who is key to the past, present, and future of chemistry and certainly beyond! |
Assies, L; Fu, C; Kovaříček, P; Bastl, Z; Drogowska, K A; Lang, J; Guerra, V L P; Samorì, P; Orgiu, E; Perepichka, D F; Kalbáč, M Dynamic covalent conjugated polymer epitaxy on graphene Article de journal Dans: J. Mater. Chem. C, 7 , p. 12240–12247, 2019. @article{Assies2019, title = {Dynamic covalent conjugated polymer epitaxy on graphene}, author = {L. Assies and C. Fu and P. Kovaříček and Z. Bastl and K. A. Drogowska and J. Lang and V. L. P. Guerra and P. Samorì and E. Orgiu and D. F. Perepichka and M. Kalbáč}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/c9tc03155c}, year = {2019}, date = {2019-09-16}, journal = {J. Mater. Chem. C}, volume = {7}, pages = {12240–12247}, abstract = { Hybrid heterostructures formed from ordered molecular layers on two-dimensional materials can have unique properties differing from those of their bulk phases. By employing principles of dynamic covalent chemistry, we have synthesized a series of novel conjugated polyimines that form epitaxial ordered monolayers on graphene. The interplay between molecular physisorption and dynamic polymerization at the solid–liquid interface drives the formation of longer chains at the surface with dramatically higher rates than in solution. The physico-chemical properties of such assemblies at different length scales on graphene were investigated by a combination of experimental techniques. ‘Covalent dynamic epitaxy’ was also found to modulate the properties of both substrate and dynamers such as doping and photoluminescence, respectively. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Hybrid heterostructures formed from ordered molecular layers on two-dimensional materials can have unique properties differing from those of their bulk phases. By employing principles of dynamic covalent chemistry, we have synthesized a series of novel conjugated polyimines that form epitaxial ordered monolayers on graphene. The interplay between molecular physisorption and dynamic polymerization at the solid–liquid interface drives the formation of longer chains at the surface with dramatically higher rates than in solution. The physico-chemical properties of such assemblies at different length scales on graphene were investigated by a combination of experimental techniques. ‘Covalent dynamic epitaxy’ was also found to modulate the properties of both substrate and dynamers such as doping and photoluminescence, respectively. |
de Oliveira, Furlan R; Livio, P A; Montes-García, V; Ippolito, S; Eredia, M; Fanjul-Bolado, P; García, González M B; Casalini, S; Samorì, P Liquid‐Gated Transistors Based on Reduced Graphene Oxide for Flexible and Wearable Electronics Article de journal Dans: Adv. Funct. Mater., 29 , p. 1905375, 2019. @article{deOliveira2019, title = {Liquid‐Gated Transistors Based on Reduced Graphene Oxide for Flexible and Wearable Electronics}, author = {R. Furlan de Oliveira and P. A. Livio and V. Montes-García and S. Ippolito and M. Eredia and P. Fanjul-Bolado and M. B. González García and S. Casalini and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adfm.201905375}, year = {2019}, date = {2019-09-15}, journal = {Adv. Funct. Mater.}, volume = {29}, pages = {1905375}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Stoeckel, M A; Gobbi, M; Leydecker, T; Wang, Y; Eredia, M; Bonacchi, S; Verucchi, R; Timpel, M; Nardi, M V; Orgiu, E; Samorì, P Boosting and Balancing Electron and Hole Mobility in Single- and Bilayer WSe2 Devices via Tailored Molecular Functionalization Article de journal Dans: ACS Nano, 13 , p. 11613–11622, 2019. @article{Stoeckel2019, title = {Boosting and Balancing Electron and Hole Mobility in Single- and Bilayer WSe2 Devices via Tailored Molecular Functionalization}, author = {M. A. Stoeckel and M. Gobbi and T. Leydecker and Y. Wang and M. Eredia and S. Bonacchi and R. Verucchi and M. Timpel and M. V. Nardi and E. Orgiu and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsnano.9b05423}, year = {2019}, date = {2019-09-11}, journal = {ACS Nano}, volume = {13}, pages = {11613–11622}, abstract = {WSe2 is a layered ambipolar semiconductor enabling hole and electron transport, which renders it a suitable active component for logic circuitry. However, solid-state devices based on single- and bilayer WSe2 typically exhibit unipolar transport and poor electrical performance when conventional SiO2 dielectric and Au electrodes are used. Here, we show that silane-containing functional molecules form ordered monolayers on the top of the WSe2 surface, thereby boosting its electrical performance in single- and bilayer field-effect transistors. In particular, by employing SiO2 dielectric substrates and top Au electrodes, we measure unipolar mobility as high as μh = 150 cm2 V–1 s–1 and μe = 17.9 cm2 V–1 s–1 in WSe2 single-layer devices when ad hoc molecular monolayers are chosen. Additionally, by asymmetric double-side functionalization with two different molecules, we provide opposite polarity to the top and bottom layer of bilayer WSe2, demonstrating nearly balanced ambipolarity at the bilayer limit. Our results indicate that the controlled functionalization of the two sides of the WSe2 mono- and bilayer flakes with highly ordered molecular monolayers offers the possibility to simultaneously achieve energy level engineering and defect functionalization, representing a path toward deterministic control over charge transport in 2D materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } WSe2 is a layered ambipolar semiconductor enabling hole and electron transport, which renders it a suitable active component for logic circuitry. However, solid-state devices based on single- and bilayer WSe2 typically exhibit unipolar transport and poor electrical performance when conventional SiO2 dielectric and Au electrodes are used. Here, we show that silane-containing functional molecules form ordered monolayers on the top of the WSe2 surface, thereby boosting its electrical performance in single- and bilayer field-effect transistors. In particular, by employing SiO2 dielectric substrates and top Au electrodes, we measure unipolar mobility as high as μh = 150 cm2 V–1 s–1 and μe = 17.9 cm2 V–1 s–1 in WSe2 single-layer devices when ad hoc molecular monolayers are chosen. Additionally, by asymmetric double-side functionalization with two different molecules, we provide opposite polarity to the top and bottom layer of bilayer WSe2, demonstrating nearly balanced ambipolarity at the bilayer limit. Our results indicate that the controlled functionalization of the two sides of the WSe2 mono- and bilayer flakes with highly ordered molecular monolayers offers the possibility to simultaneously achieve energy level engineering and defect functionalization, representing a path toward deterministic control over charge transport in 2D materials. |
Hou, I C -Y; Diez-Cabanes, V; Galanti, A; Valášek, M; Mayor, M; Cornil, J; Narita, A; Samorì, P; Müllen, K Photomodulation of Two-Dimensional Self-Assembly of Azobenzene–Hexa-peri-hexabenzocoronene–Azobenzene Triads Article de journal Dans: Chem. Mater., 31 , p. 6979–6985, 2019. @article{Hou2019, title = {Photomodulation of Two-Dimensional Self-Assembly of Azobenzene–Hexa-peri-hexabenzocoronene–Azobenzene Triads}, author = {I. C.-Y. Hou and V. Diez-Cabanes and A. Galanti and M. Valášek and M. Mayor and J. Cornil and A. Narita and P. Samorì and K. Müllen }, editor = {ACS}, url = {https://doi.org/10.1021/acs.chemmater.9b01535}, year = {2019}, date = {2019-09-10}, journal = {Chem. Mater.}, volume = {31}, pages = {6979–6985}, abstract = {Achieving exquisite control over self-assembly of functional polycyclic aromatic hydrocarbons (PAH) and nanographene (NG) is essential for their exploitation as active elements in (nano)technological applications. In the framework of our effort to leverage their functional complexity, we designed and synthesized two hexa-peri-hexabenzocoronene (HBC) triads, pAHA and oAHA, decorated with two light-responsive azobenzene moieties at the pseudo-para and ortho positions, respectively. Their photoisomerization in solution is demonstrated by UV–vis absorption. 1H NMR measurements of oAHA suggested 23% of Z-form can be obtained at a photostationary state with UV irradiation (366 nm). Scanning tunneling microscopy imaging revealed that the self-assembly of pAHA and oAHA at the solid–liquid interface between highly oriented pyrolytic graphite (HOPG) and their solution in 1,2,4-trichlorobenzene can be modulated upon light irradiation. This is in contrast to our previous work using HBC bearing a single azobenzene moiety, which did not show such photomodulation of the self-assembled structure. Upon E-Z isomerization both pAHA and oAHA displayed an increased packing density on the surface of graphite. Moreover, pAHA revealed a change of self-assembled pattern from an oblique unit cell to a dimer row rectangular crystal lattice whereas the assembly of oAHA retained a dimer row structure before and after light irradiation, yet with a modification of the inter-row molecular orientation. Molecular mechanics/molecular dynamics simulations validated the self-assembly patterns of pAHA and oAHA, comprising azobenzenes in their Z-forms. These results pave the way toward use of suitably functionalized large PAHs, as well as NGs, to develop photoswitchable devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Achieving exquisite control over self-assembly of functional polycyclic aromatic hydrocarbons (PAH) and nanographene (NG) is essential for their exploitation as active elements in (nano)technological applications. In the framework of our effort to leverage their functional complexity, we designed and synthesized two hexa-peri-hexabenzocoronene (HBC) triads, pAHA and oAHA, decorated with two light-responsive azobenzene moieties at the pseudo-para and ortho positions, respectively. Their photoisomerization in solution is demonstrated by UV–vis absorption. 1H NMR measurements of oAHA suggested 23% of Z-form can be obtained at a photostationary state with UV irradiation (366 nm). Scanning tunneling microscopy imaging revealed that the self-assembly of pAHA and oAHA at the solid–liquid interface between highly oriented pyrolytic graphite (HOPG) and their solution in 1,2,4-trichlorobenzene can be modulated upon light irradiation. This is in contrast to our previous work using HBC bearing a single azobenzene moiety, which did not show such photomodulation of the self-assembled structure. Upon E-Z isomerization both pAHA and oAHA displayed an increased packing density on the surface of graphite. Moreover, pAHA revealed a change of self-assembled pattern from an oblique unit cell to a dimer row rectangular crystal lattice whereas the assembly of oAHA retained a dimer row structure before and after light irradiation, yet with a modification of the inter-row molecular orientation. Molecular mechanics/molecular dynamics simulations validated the self-assembly patterns of pAHA and oAHA, comprising azobenzenes in their Z-forms. These results pave the way toward use of suitably functionalized large PAHs, as well as NGs, to develop photoswitchable devices. |
Leydecker, T; Squillaci, M A; Liscio, F; Orgiu, E; Samorì, P Controlling Ambipolar Transport and Voltage Inversion in Solution-Processed Thin-Film Devices through Polymer Blending Article de journal Dans: Chem. Mater., 31 , p. 6491–6498, 2019. @article{Leydecker2019, title = {Controlling Ambipolar Transport and Voltage Inversion in Solution-Processed Thin-Film Devices through Polymer Blending}, author = {T. Leydecker and M. A. Squillaci and F. Liscio and E. Orgiu and P. Samorì}, editor = {ACS}, url = {https://doi.org/10.1021/acs.chemmater.8b04819}, year = {2019}, date = {2019-09-10}, journal = {Chem. Mater.}, volume = {31}, pages = {6491–6498}, abstract = {Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and logic applications. Field-effect transistors built on solution-processable ambipolar materials hold strong promise for the engineering of large-area low-cost logic circuits with a reduced number of devices components. Such devices still suffer from a number of obstacles including the challenging processing, the low Ion/Ioff, the unbalanced mobility, and the low gain in complementary metal–oxide–semiconductor (CMOS)-like circuits. Here, we demonstrate that the simple approach of blending commercially available n- and p-type polymers such as P(NDI2OD-T2), P3HT, PCD-TPT, PDVT-8, and IIDDT-C3 can yield high-performing ambipolar field-effect transistors with balanced mobilities and Ion/Ioff > 107. Each single component was studied separately and upon blending by means of electrical characterization, ambient ultraviolet photoelectron spectroscopy, atomic force microscopy, and grazing incidence wide angle X-ray scattering to unravel the correlation between the morphology/structure of the semiconducting films and their functions. Blends of n- and p-type semiconductors were used to fabricate CMOS-like inverter circuits with state-of-the-art gains over 160 in the case of P(NDI2OD-T2) blended with PDVT-8. Significantly, our blending approach was successful in producing semiconducting films with balanced mobilities for each of the four tested semiconductor blends, although the films displayed different structural and morphological features. Our strategy, which relies on establishing a correlation between ambipolar performances, film morphology, molecular structure, and blending ratio, is extremely efficient and versatile; thus it could be applied to a wide range of polymers or solution processable small molecules.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and logic applications. Field-effect transistors built on solution-processable ambipolar materials hold strong promise for the engineering of large-area low-cost logic circuits with a reduced number of devices components. Such devices still suffer from a number of obstacles including the challenging processing, the low Ion/Ioff, the unbalanced mobility, and the low gain in complementary metal–oxide–semiconductor (CMOS)-like circuits. Here, we demonstrate that the simple approach of blending commercially available n- and p-type polymers such as P(NDI2OD-T2), P3HT, PCD-TPT, PDVT-8, and IIDDT-C3 can yield high-performing ambipolar field-effect transistors with balanced mobilities and Ion/Ioff > 107. Each single component was studied separately and upon blending by means of electrical characterization, ambient ultraviolet photoelectron spectroscopy, atomic force microscopy, and grazing incidence wide angle X-ray scattering to unravel the correlation between the morphology/structure of the semiconducting films and their functions. Blends of n- and p-type semiconductors were used to fabricate CMOS-like inverter circuits with state-of-the-art gains over 160 in the case of P(NDI2OD-T2) blended with PDVT-8. Significantly, our blending approach was successful in producing semiconducting films with balanced mobilities for each of the four tested semiconductor blends, although the films displayed different structural and morphological features. Our strategy, which relies on establishing a correlation between ambipolar performances, film morphology, molecular structure, and blending ratio, is extremely efficient and versatile; thus it could be applied to a wide range of polymers or solution processable small molecules. |
Mahmood, A; Yang, C -S; Jang, S; Routaboul, L; Chang, H; Ghisolfi, A; Braunstein, P; Bernard, L; Verduci, T; Dayen, J -F; Samorì, P; Lee, J -O; Doudin, B Tuning graphene transistors through ad hoc electrostatics induced by a nanometer-thick molecular underlayer Article de journal Dans: Nanoscale, 11 , p. 19705–19712, 2019. @article{Mahmood2019, title = {Tuning graphene transistors through ad hoc electrostatics induced by a nanometer-thick molecular underlayer}, author = {A. Mahmood and C.-S. Yang and S. Jang and L. Routaboul and H. Chang and A. Ghisolfi and P. Braunstein and L. Bernard and T. Verduci and J.-F. Dayen and P. Samorì and J.-O Lee and B. Doudin}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/c9nr06407a}, year = {2019}, date = {2019-09-05}, journal = {Nanoscale}, volume = {11}, pages = {19705–19712}, abstract = {We report on the modulation of the electrical properties of graphene-based transistors that mirror the properties of a few nanometers thick layer made of dipolar molecules sandwiched in between the 2D material and the SiO2 dielectric substrate. The chemical composition of the films of quinonemonoimine zwitterion molecules adsorbed onto SiO2 has been explored by means of X-ray photoemission and mass spectroscopy. Graphene-based devices are then fabricated by transferring the 2D material onto the molecular film, followed by the deposition of top source–drain electrodes. The degree of supramolecular order in disordered films of dipolar molecules was found to be partially improved as a result of the electric field at low temperatures, as revealed by the emergence of hysteresis in the transfer curves of the transistors. The use of molecules from the same family, which are suitably designed to interact with the dielectric surface, results in the disappearance of the hysteresis. DFT calculations confirm that the dressing of the molecules by an external electric field exhibits multiple minimal energy landscapes that explain the thermally stabilized capacitive coupling observed. This study demonstrates that the design and exploitation of ad hoc molecules as an interlayer between a dielectric substrate and graphene represents a powerful tool for tuning the electrical properties of the 2D material. Conversely, graphene can be used as an indicator of the stability of molecular layers, by providing insight into the energetics of ordering of dipolar molecules under the effect of electrical gating. }, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on the modulation of the electrical properties of graphene-based transistors that mirror the properties of a few nanometers thick layer made of dipolar molecules sandwiched in between the 2D material and the SiO2 dielectric substrate. The chemical composition of the films of quinonemonoimine zwitterion molecules adsorbed onto SiO2 has been explored by means of X-ray photoemission and mass spectroscopy. Graphene-based devices are then fabricated by transferring the 2D material onto the molecular film, followed by the deposition of top source–drain electrodes. The degree of supramolecular order in disordered films of dipolar molecules was found to be partially improved as a result of the electric field at low temperatures, as revealed by the emergence of hysteresis in the transfer curves of the transistors. The use of molecules from the same family, which are suitably designed to interact with the dielectric surface, results in the disappearance of the hysteresis. DFT calculations confirm that the dressing of the molecules by an external electric field exhibits multiple minimal energy landscapes that explain the thermally stabilized capacitive coupling observed. This study demonstrates that the design and exploitation of ad hoc molecules as an interlayer between a dielectric substrate and graphene represents a powerful tool for tuning the electrical properties of the 2D material. Conversely, graphene can be used as an indicator of the stability of molecular layers, by providing insight into the energetics of ordering of dipolar molecules under the effect of electrical gating. |
Mohankumar, M; Chattopadhyay, B; Hadji, R; Sanguinet, L; Kennedy, A R; Lemaur, V; Cornil, J; Fenwick, O; Samorì, P; Geerts, Y Oxacycle‐Fused [1]Benzothieno[3,2‐b][1]benzothiophene Derivatives: Synthesis, Electronic Structure, Electrochemical Properties, Ionisation Potential, and Crystal Structure Article de journal Dans: ChemPlusChem, 84 , p. 1263–1269, 2019. @article{Mohankumar2019, title = {Oxacycle‐Fused [1]Benzothieno[3,2‐b][1]benzothiophene Derivatives: Synthesis, Electronic Structure, Electrochemical Properties, Ionisation Potential, and Crystal Structure}, author = {M. Mohankumar and B. Chattopadhyay and R. Hadji and L. Sanguinet and A. R. Kennedy and V. Lemaur and J. Cornil and O. Fenwick and P. Samorì and Y. Geerts}, editor = {Wiley}, url = {https://doi.org/10.1002/cplu.201800346}, year = {2019}, date = {2019-09-02}, journal = {ChemPlusChem}, volume = {84}, pages = {1263–1269}, abstract = {The molecular properties of [1]benzothieno[3,2‐b][1]benzothiophene (BTBT) are vulnerable to structural modifications, which in turn are determined by the functionalization of the backbone. Hence versatile synthetic strategies are needed to discover the properties of this molecule. To address this, we have attempted heteroatom (oxygen) functionalization of BTBT by a concise and easily scalable synthesis. Fourfold hydroxy‐substituted BTBT is the key intermediate, from which the compounds 2,3,7,8‐bis(ethylenedioxy)‐[1]benzothieno[3,2‐b][1]benzothiophene and 2,3,7,8‐bis(methylenedioxy)‐[1]benzothieno[3,2‐b][1]benzothiophene are synthesized. The difference in ether functionalities on the BTBT scaffold influences the ionisation potential values substantially. The crystal structure reveals the transformation of the herringbone motif in bare BTBT towards π‐stacked columns in the newly synthesized derivatives. The results are further justified by the simulated HOMO levels of the model compound...}, keywords = {}, pubstate = {published}, tppubtype = {article} } The molecular properties of [1]benzothieno[3,2‐b][1]benzothiophene (BTBT) are vulnerable to structural modifications, which in turn are determined by the functionalization of the backbone. Hence versatile synthetic strategies are needed to discover the properties of this molecule. To address this, we have attempted heteroatom (oxygen) functionalization of BTBT by a concise and easily scalable synthesis. Fourfold hydroxy‐substituted BTBT is the key intermediate, from which the compounds 2,3,7,8‐bis(ethylenedioxy)‐[1]benzothieno[3,2‐b][1]benzothiophene and 2,3,7,8‐bis(methylenedioxy)‐[1]benzothieno[3,2‐b][1]benzothiophene are synthesized. The difference in ether functionalities on the BTBT scaffold influences the ionisation potential values substantially. The crystal structure reveals the transformation of the herringbone motif in bare BTBT towards π‐stacked columns in the newly synthesized derivatives. The results are further justified by the simulated HOMO levels of the model compound... |
Samorì, P; Feng, X; Bonifazi, D π‐Conjugated Molecules: From Structure to Function Article de journal Dans: ChemPlusChem, 84 , p. 1177–1178, 2019. @article{Samorì2019b, title = {π‐Conjugated Molecules: From Structure to Function}, author = {P. Samorì and X. Feng and D. Bonifazi}, editor = {Wiley}, url = {https://doi.org/10.1002/cplu.201900442}, year = {2019}, date = {2019-08-23}, journal = {ChemPlusChem}, volume = {84}, pages = {1177–1178}, abstract = {Appealing properties: ChemPlusChem is proud to present its Special Issue on π‐Conjugated Molecules and their Applications, guest‐edited by Paolo Samorí, Xinliang Feng, and Davide Bonifazi. It contains both research and review articles that feature some of the most enlightening approaches on the synthesis of novel conjugated (macro)molecules, and highlights their special chemical and physical properties arising from the π‐conjugation, as well as their processing and self‐assembly at surfaces and interfaces, and integration into a range of devices. Since the discovery and development of conductive polymers in the 1970s, which led to the award of the Nobel Prize in Chemistry 2000 to Alan. J. Heeger, Alan. G. MacDiarmid, and Hideki Shirakawa, an ever‐increasing effort is being devoted to the science and technology of π‐conjugated molecules and macromolecules. These systems display unique properties that make them appealing for a multitude of applications in optoelectronics, photonics, energy, and (bio)sensing. Compared to their inorganic counterparts, the greatest advantages of π‐conjugated (macro)molecules lie in the molecular‐level tunability of their optoelectronic properties and their processability into thin films through cheap and easily scalable methods. Furthermore, macromolecular derivatives can feature mechanical properties (flexibility, toughness, malleability, elasticity, etc.) typical of plastics thus making it possible to fabricate nonplanar and even flexible yet robust devices. The fabrication and technology of plastic optoelectronics is an area of intense international investigation where one of the ultimate goals is to develop smart and multifunctional devices such as LEDs, solar cells, field‐effect transistors, and related applications in flexible active‐matrix electronic‐paper displays, sensing, and radiofrequency identification (RDIF) tags. The knowledge developed in this field will also lead to potential technological breakthroughs in organic nanophotonics, nanoelectronics, spintronics, and data‐storage, as well as novel approaches to smart textiles, medical diagnostic tools (e.g. lab‐on‐a‐chip), biocompatible devices (from artificial retinas to synthetic muscles), and flexible batteries. At the basis of this interdisciplinary research endeavor, one can find the synthesis of more and more sophisticated 1D, 2D, and 3D (macro)molecular building blocks that are designed to exhibit specific physical and chemical properties. In particular, the synthesis of such systems that possess different structures and dimensionalities, as well as being characterized by multiple and regiospecific substitutions with functional groups at the core, in the scaffold and/or in the periphery, makes it possible to improve fundamental photophysical properties, namely excitation energy and electron transfer. This will allow, among others, tuning of absorption and emission properties, increases in thermal and (photo)chemical stability, enhancement of molar absorptivities and fluorescence quantum efficiencies, and generation of nonlinear optical responses. It is widely established that the properties of organic and polymeric materials, either arranged as thin or thicker films, strongly depend on the organization at the supramolecular level. This means that the materials and device properties are determined not only by those intrinsic to the structure of the constituent molecules (molecular level) but also by those resulting from the interactions between adjacent molecules (supramolecular level). In particular, there are many physical properties, such as charge transfer (through hopping), charge split and recombination, and exciton diffusion, to name but a few, that depend more critically on the supramolecular organization. In light of this, the self‐assembly and self‐organization of macromolecules at surfaces and interfaces are key, also to enabling optimal interfacial properties such as charge injection and extraction via energy matching. Such a control over these physical properties at the molecular and supramolecular level is therefore of paramount importance for improved device performance. This Special Issue highlights some of the most enlightening approaches on the synthesis of novel conjugated (macro)molecules with special properties arising from their π‐conjugation, their processing and self‐assembly at surfaces and interfaces, their multiscale analysis of the relevant physical and chemical properties, and their integration in optoelectronic, photovoltaics, batteries, and chemical sensing devices. Images from the Review and Minireview articles, as well as the paper featured on the cover are shown here. We believe that this Special Issue will offer readers some inspiring examples of the wide scope of this field of science and technology and hopefully convey the enthusiasm of the scientists involved in this research. We are most grateful to all contributing authors for their effort in highlighting and addressing the key questions in this highly dynamic field of chemistry at its interface with physics and engineering, in the interdisciplinary realms of materials and nanoscience. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Appealing properties: ChemPlusChem is proud to present its Special Issue on π‐Conjugated Molecules and their Applications, guest‐edited by Paolo Samorí, Xinliang Feng, and Davide Bonifazi. It contains both research and review articles that feature some of the most enlightening approaches on the synthesis of novel conjugated (macro)molecules, and highlights their special chemical and physical properties arising from the π‐conjugation, as well as their processing and self‐assembly at surfaces and interfaces, and integration into a range of devices. Since the discovery and development of conductive polymers in the 1970s, which led to the award of the Nobel Prize in Chemistry 2000 to Alan. J. Heeger, Alan. G. MacDiarmid, and Hideki Shirakawa, an ever‐increasing effort is being devoted to the science and technology of π‐conjugated molecules and macromolecules. These systems display unique properties that make them appealing for a multitude of applications in optoelectronics, photonics, energy, and (bio)sensing. Compared to their inorganic counterparts, the greatest advantages of π‐conjugated (macro)molecules lie in the molecular‐level tunability of their optoelectronic properties and their processability into thin films through cheap and easily scalable methods. Furthermore, macromolecular derivatives can feature mechanical properties (flexibility, toughness, malleability, elasticity, etc.) typical of plastics thus making it possible to fabricate nonplanar and even flexible yet robust devices. The fabrication and technology of plastic optoelectronics is an area of intense international investigation where one of the ultimate goals is to develop smart and multifunctional devices such as LEDs, solar cells, field‐effect transistors, and related applications in flexible active‐matrix electronic‐paper displays, sensing, and radiofrequency identification (RDIF) tags. The knowledge developed in this field will also lead to potential technological breakthroughs in organic nanophotonics, nanoelectronics, spintronics, and data‐storage, as well as novel approaches to smart textiles, medical diagnostic tools (e.g. lab‐on‐a‐chip), biocompatible devices (from artificial retinas to synthetic muscles), and flexible batteries. At the basis of this interdisciplinary research endeavor, one can find the synthesis of more and more sophisticated 1D, 2D, and 3D (macro)molecular building blocks that are designed to exhibit specific physical and chemical properties. In particular, the synthesis of such systems that possess different structures and dimensionalities, as well as being characterized by multiple and regiospecific substitutions with functional groups at the core, in the scaffold and/or in the periphery, makes it possible to improve fundamental photophysical properties, namely excitation energy and electron transfer. This will allow, among others, tuning of absorption and emission properties, increases in thermal and (photo)chemical stability, enhancement of molar absorptivities and fluorescence quantum efficiencies, and generation of nonlinear optical responses. It is widely established that the properties of organic and polymeric materials, either arranged as thin or thicker films, strongly depend on the organization at the supramolecular level. This means that the materials and device properties are determined not only by those intrinsic to the structure of the constituent molecules (molecular level) but also by those resulting from the interactions between adjacent molecules (supramolecular level). In particular, there are many physical properties, such as charge transfer (through hopping), charge split and recombination, and exciton diffusion, to name but a few, that depend more critically on the supramolecular organization. In light of this, the self‐assembly and self‐organization of macromolecules at surfaces and interfaces are key, also to enabling optimal interfacial properties such as charge injection and extraction via energy matching. Such a control over these physical properties at the molecular and supramolecular level is therefore of paramount importance for improved device performance. This Special Issue highlights some of the most enlightening approaches on the synthesis of novel conjugated (macro)molecules with special properties arising from their π‐conjugation, their processing and self‐assembly at surfaces and interfaces, their multiscale analysis of the relevant physical and chemical properties, and their integration in optoelectronic, photovoltaics, batteries, and chemical sensing devices. Images from the Review and Minireview articles, as well as the paper featured on the cover are shown here. We believe that this Special Issue will offer readers some inspiring examples of the wide scope of this field of science and technology and hopefully convey the enthusiasm of the scientists involved in this research. We are most grateful to all contributing authors for their effort in highlighting and addressing the key questions in this highly dynamic field of chemistry at its interface with physics and engineering, in the interdisciplinary realms of materials and nanoscience. |
Pavlica, E; Pastukhova, N; Nawrocki, R A; Ciesielski, A; Tkachuk, V; Samorì, P; Bratina, G Enhancement of Charge Transport in Polythiophene Semiconducting Polymer by Blending with Graphene Nanoparticles Article de journal Dans: ChemPlusChem, 84 , p. 1366–1374, 2019. @article{Pavlica2019, title = {Enhancement of Charge Transport in Polythiophene Semiconducting Polymer by Blending with Graphene Nanoparticles}, author = {E. Pavlica and N. Pastukhova and R. A. Nawrocki and A. Ciesielski and V. Tkachuk and P. Samorì and G. Bratina}, editor = {Wiley}, url = {https://doi.org/10.1002/cplu.201900219}, year = {2019}, date = {2019-08-21}, journal = {ChemPlusChem}, volume = {84}, pages = {1366–1374}, abstract = {This paper describes a study on the charge transport in a composite of liquid‐exfoliated graphene nanoparticles (GNPs) and a polythiophene semiconducting polymer. While the former component is highly conducting, although it consists of isolated nanostructures, the latter offers an efficient charge transport path between the individual GNPs within the film, overall yielding enhanced charge transport properties of the resulting bi‐component system. The electrical characteristics of the composite layers were investigated by means of measurements of time‐of‐flight photoconductivity and transconductance in field‐effect transistors. In order to analyze both phenomena separately, charge density and charge mobility contributions to the conductivity were singled out. With the increasing GNP concentration, the charge mobility was found to increase, thereby reducing the time spent by the carriers on the polymer chains. In addition, for GNP loading above 0.2 % (wt.), an increase of free charge density was observed that highlights an additional key role played by doping. Variable‐range hopping model of a mixed two‐ and three‐dimensional transport is explained using temperature dependence of mobility and free charge density. The temperature variation of free charge density was related to the electron transfer from polythiophene to GNP, with an energy barrier of 24 meV...}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper describes a study on the charge transport in a composite of liquid‐exfoliated graphene nanoparticles (GNPs) and a polythiophene semiconducting polymer. While the former component is highly conducting, although it consists of isolated nanostructures, the latter offers an efficient charge transport path between the individual GNPs within the film, overall yielding enhanced charge transport properties of the resulting bi‐component system. The electrical characteristics of the composite layers were investigated by means of measurements of time‐of‐flight photoconductivity and transconductance in field‐effect transistors. In order to analyze both phenomena separately, charge density and charge mobility contributions to the conductivity were singled out. With the increasing GNP concentration, the charge mobility was found to increase, thereby reducing the time spent by the carriers on the polymer chains. In addition, for GNP loading above 0.2 % (wt.), an increase of free charge density was observed that highlights an additional key role played by doping. Variable‐range hopping model of a mixed two‐ and three‐dimensional transport is explained using temperature dependence of mobility and free charge density. The temperature variation of free charge density was related to the electron transfer from polythiophene to GNP, with an energy barrier of 24 meV... |
Squillaci, M A; Stoeckel, M -A; Samorì, P 3D hybrid networks of gold nanoparticles: mechanoresponsive electrical humidity sensors with on-demand performances Article de journal Dans: Nanoscale, 11 , p. 19319–19326, 2019. @article{Squillaci2019, title = {3D hybrid networks of gold nanoparticles: mechanoresponsive electrical humidity sensors with on-demand performances}, author = {M. A. Squillaci and M.-A. Stoeckel and P. Samorì}, editor = {Royal Society of Chemistry }, url = {https://doi.org/10.1039/c9nr05336k}, year = {2019}, date = {2019-08-15}, journal = {Nanoscale}, volume = {11}, pages = {19319–19326}, abstract = {We have engineered macroscopic 3D porous networks of gold nanoparticles (AuNPs) chemically interconnected by di-thiolated ethylene glycol oligomers. The formation of such superstructures has been followed by means of UV-Vis spectroscopy by monitoring the aggregation-dependent plasmonic band of such nanomaterials. The controlled chemical tethering of the AuNPs with di-thiolated linkers possessing a well-defined contour length rules the interparticle distance. The use of ad-hoc linkers ensures charge transport via direct tunneling and the hygroscopic nature of the ethylene glycol backbone allows interaction with moisture. Upon interaction with water molecules from the atmosphere, our 3D networks undergo swelling reducing the tunnelling current passing through the system. By exploiting such a behavior, we have devised a new approach for the fabrication of electrical resistive humidity sensors. For the first time we have also introduced a new strategy to fabricate stable and robust devices by covalently attaching our 3D networks to gold electrodes. Devices comprising both 4 (TEG) or 6 (HEG) ethylene glycol repetitive units combined with AuNPs exhibited (i) unprecedentedly high response speed (∼26 ms), (ii) short recovery time (∼250 ms) in the absence of any hysteresis effect, and (iii) a linear response to humidity changes characterized by a highest sensitivity of 51 kΩ per RH(%) for HEG- and 500 Ω per RH(%) for TEG-based devices. The employed green solution processing in water and the extreme robustness of our 3D networks make them interesting candidates for the fabrication of sensors which can operate under extreme conditions and for countless cycles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We have engineered macroscopic 3D porous networks of gold nanoparticles (AuNPs) chemically interconnected by di-thiolated ethylene glycol oligomers. The formation of such superstructures has been followed by means of UV-Vis spectroscopy by monitoring the aggregation-dependent plasmonic band of such nanomaterials. The controlled chemical tethering of the AuNPs with di-thiolated linkers possessing a well-defined contour length rules the interparticle distance. The use of ad-hoc linkers ensures charge transport via direct tunneling and the hygroscopic nature of the ethylene glycol backbone allows interaction with moisture. Upon interaction with water molecules from the atmosphere, our 3D networks undergo swelling reducing the tunnelling current passing through the system. By exploiting such a behavior, we have devised a new approach for the fabrication of electrical resistive humidity sensors. For the first time we have also introduced a new strategy to fabricate stable and robust devices by covalently attaching our 3D networks to gold electrodes. Devices comprising both 4 (TEG) or 6 (HEG) ethylene glycol repetitive units combined with AuNPs exhibited (i) unprecedentedly high response speed (∼26 ms), (ii) short recovery time (∼250 ms) in the absence of any hysteresis effect, and (iii) a linear response to humidity changes characterized by a highest sensitivity of 51 kΩ per RH(%) for HEG- and 500 Ω per RH(%) for TEG-based devices. The employed green solution processing in water and the extreme robustness of our 3D networks make them interesting candidates for the fabrication of sensors which can operate under extreme conditions and for countless cycles. |
Qiu, H; Zhao, Y; Liu, Z; Herder, M; Hecht, S; Samorì, P Modulating the Charge Transport in 2D Semiconductors via Energy‐Level Phototuning Article de journal Dans: Adv. Mater., 31 , p. 1903402, 2019. @article{Qiu2019, title = {Modulating the Charge Transport in 2D Semiconductors via Energy‐Level Phototuning}, author = {H. Qiu and Y. Zhao and Z. Liu and M. Herder and S. Hecht and P. Samorì}, editor = {Wiley}, url = {https://doi.org/10.1002/adma.201903402}, year = {2019}, date = {2019-08-12}, journal = {Adv. Mater.}, volume = {31}, pages = {1903402}, abstract = {The controlled functionalization of semiconducting 2D materials (2DMs) with photoresponsive molecules enables the generation of novel hybrid structures as active components for the fabrication of high‐performance multifunctional field‐effect transistors (FETs) and memories. This study reports the realization of optically switchable FETs by decorating the surface of the semiconducting 2DMs such as WSe2 and black phosphorus with suitably designed diarylethene (DAE) molecules to modulate their electron and hole transport, respectively, without sacrificing their pristine electrical performance. The efficient and reversible photochemical isomerization of the DAEs between the open and the closed isomer, featuring different energy levels, makes it possible to generate photoswitchable charge trapping levels, resulting in the tuning of charge transport through the 2DMs by alternating illumination with UV and visible light. The device reveals excellent data‐retention capacity combined with multiple and well‐distinguished accessible current levels, paving the way for its use as an active element in multilevel memories.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The controlled functionalization of semiconducting 2D materials (2DMs) with photoresponsive molecules enables the generation of novel hybrid structures as active components for the fabrication of high‐performance multifunctional field‐effect transistors (FETs) and memories. This study reports the realization of optically switchable FETs by decorating the surface of the semiconducting 2DMs such as WSe2 and black phosphorus with suitably designed diarylethene (DAE) molecules to modulate their electron and hole transport, respectively, without sacrificing their pristine electrical performance. The efficient and reversible photochemical isomerization of the DAEs between the open and the closed isomer, featuring different energy levels, makes it possible to generate photoswitchable charge trapping levels, resulting in the tuning of charge transport through the 2DMs by alternating illumination with UV and visible light. The device reveals excellent data‐retention capacity combined with multiple and well‐distinguished accessible current levels, paving the way for its use as an active element in multilevel memories. |
Liu, Z; Zhang, H; Eredia, M; Qiu, H; Baaziz, W; Ersen, O; Ciesielski, A; Bonn, M; Wang, H I; Samorì, P Water-Dispersed High-Quality Graphene: A Green Solution for Efficient Energy Storage Applications Article de journal Dans: ACS Nano, 13 , p. 9431–9441, 2019. @article{Liu2019, title = {Water-Dispersed High-Quality Graphene: A Green Solution for Efficient Energy Storage Applications}, author = {Z. Liu and H. Zhang and M. Eredia and H. Qiu and W. Baaziz and O. Ersen and A. Ciesielski and M. Bonn and H. I. Wang and P. Samorì}, editor = {ACS}, url = {https://doi.org/10.1021/acsnano.9b04232}, year = {2019}, date = {2019-08-06}, journal = {ACS Nano}, volume = {13}, pages = {9431–9441}, abstract = {Graphene has been the subject of widespread research during the past decade because of its outstanding physical properties which make it an ideal nanoscale material to investigate fundamental properties. Such characteristics promote graphene as a functional material for the emergence of disruptive technologies. However, to impact daily life products and devices, high-quality graphene needs to be produced in large quantities using an environmentally friendly protocol. In this context, the production of graphene which preserves its outstanding electronic properties using a green chemistry approach remains a key challenge. Herein, we report the efficient production of electrode material for micro-supercapacitors obtained by functionalization of water-dispersed high-quality graphene nanosheets with polydopamine. High-frequency (terahertz) conductivity measurements of the graphene nanosheets reveal high charge carrier mobility up to 1000 cm–2 V–1 s–1. The fine water dispersibility enables versatile functionalization of graphene, as demonstrated by the pseudocapacitive polydopamine coating of graphene nanosheets. The polydopamine functionalization causes a modest, i.e., 20%, reduction of charge carrier mobility. Thin film electrodes based on such hybrid materials for micro-supercapacitors exhibit excellent electrochemical performance, namely a volumetric capacitance of 340 F cm–3 and a power density of 1000 W cm–3, thus outperforming most of the reported graphene-based micro-supercapacitors. These results highlight the potential for water-dispersed, high-quality graphene nanosheets as a platform material for energy-storage applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Graphene has been the subject of widespread research during the past decade because of its outstanding physical properties which make it an ideal nanoscale material to investigate fundamental properties. Such characteristics promote graphene as a functional material for the emergence of disruptive technologies. However, to impact daily life products and devices, high-quality graphene needs to be produced in large quantities using an environmentally friendly protocol. In this context, the production of graphene which preserves its outstanding electronic properties using a green chemistry approach remains a key challenge. Herein, we report the efficient production of electrode material for micro-supercapacitors obtained by functionalization of water-dispersed high-quality graphene nanosheets with polydopamine. High-frequency (terahertz) conductivity measurements of the graphene nanosheets reveal high charge carrier mobility up to 1000 cm–2 V–1 s–1. The fine water dispersibility enables versatile functionalization of graphene, as demonstrated by the pseudocapacitive polydopamine coating of graphene nanosheets. The polydopamine functionalization causes a modest, i.e., 20%, reduction of charge carrier mobility. Thin film electrodes based on such hybrid materials for micro-supercapacitors exhibit excellent electrochemical performance, namely a volumetric capacitance of 340 F cm–3 and a power density of 1000 W cm–3, thus outperforming most of the reported graphene-based micro-supercapacitors. These results highlight the potential for water-dispersed, high-quality graphene nanosheets as a platform material for energy-storage applications. |
Squillaci, M A; Zhong, X; Peyruchat, L; Genet, C; Ebbesen, T W; Samorì, P 2D hybrid networks of gold nanoparticles: mechanoresponsive optical humidity sensors Article de journal Dans: Nanoscale, 11 , p. 19315–19318, 2019. @article{Squillaci2019b, title = {2D hybrid networks of gold nanoparticles: mechanoresponsive optical humidity sensors}, author = {M. A. Squillaci and X. Zhong and L. Peyruchat and C. Genet and T. W. Ebbesen and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/c9nr05337a}, year = {2019}, date = {2019-08-05}, journal = {Nanoscale}, volume = {11}, pages = {19315–19318}, abstract = {Plasmonic coupling is a fascinating phenomenon occurring between neighboring metal nanostructures. We report a straightforward approach to study such process macroscopically by fabricating 2D networks of gold nanoparticles, interconnected with responsive hygroscopic organic linkers. By controlling the humidity we tune the interparticle distance to reversibly trigger plasmonic coupling collectively over several millimeters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plasmonic coupling is a fascinating phenomenon occurring between neighboring metal nanostructures. We report a straightforward approach to study such process macroscopically by fabricating 2D networks of gold nanoparticles, interconnected with responsive hygroscopic organic linkers. By controlling the humidity we tune the interparticle distance to reversibly trigger plasmonic coupling collectively over several millimeters. |
Ippolito, S; Ciesielski, A; Samorì, P Tailoring the physicochemical properties of solution-processed transition metal dichalcogenides via molecular approaches Article de journal Dans: Chem. Commun, 55 , p. 8900–8914, 2019. @article{Ippolito2019, title = {Tailoring the physicochemical properties of solution-processed transition metal dichalcogenides via molecular approaches}, author = {S. Ippolito and A. Ciesielski and P. Samorì}, editor = {RSC }, url = {https://doi.org/10.1039/c9cc03845k}, year = {2019}, date = {2019-06-27}, journal = {Chem. Commun}, volume = {55}, pages = {8900–8914}, abstract = {During the last five years, the scientific community has witnessed tremendous progress in solution-processed semiconducting 2D transition metal dichalcogenides (TMDs), in combination with the use of chemical approaches to finely tune their electrical, optical, mechanical and thermal properties. Because of the strong structure–properties relationship, the adopted production methods contribute in affecting the quality and characteristics of the nanomaterials, along with the costs, scalability and yield of the process. Nevertheless, a number of (supra)molecular approaches have been developed to meticulously tailor the properties of TMDs via formation of both covalent and non-covalent bonds, where small molecules, (bio)polymers or nanoparticles interact with the basal plane and/or edges of the 2D nanosheets in a controlled fashion. In this Feature Article, we will highlight the recent advancements in the development of production strategies and molecular approaches for tailoring the properties of solution-processed TMD nanosheets. We will also discuss opportunities and challenges towards the realization of multifunctional devices and sensors based on such novel hybrid nanomaterials. }, keywords = {}, pubstate = {published}, tppubtype = {article} } During the last five years, the scientific community has witnessed tremendous progress in solution-processed semiconducting 2D transition metal dichalcogenides (TMDs), in combination with the use of chemical approaches to finely tune their electrical, optical, mechanical and thermal properties. Because of the strong structure–properties relationship, the adopted production methods contribute in affecting the quality and characteristics of the nanomaterials, along with the costs, scalability and yield of the process. Nevertheless, a number of (supra)molecular approaches have been developed to meticulously tailor the properties of TMDs via formation of both covalent and non-covalent bonds, where small molecules, (bio)polymers or nanoparticles interact with the basal plane and/or edges of the 2D nanosheets in a controlled fashion. In this Feature Article, we will highlight the recent advancements in the development of production strategies and molecular approaches for tailoring the properties of solution-processed TMD nanosheets. We will also discuss opportunities and challenges towards the realization of multifunctional devices and sensors based on such novel hybrid nanomaterials. |
Ruiz-Carretero, A; Atoini, Y; Han, T; Operamolla, A; Ippolito, S; Valentini, C; Carrara, S; Sinn, S; Prasetyanto, E A; Heiser, T; Samorì, P; Farinola, G; Cola, De L Charge transport enhancement in supramolecular oligothiophene assemblies using Pt(II) centers as a guide Article de journal Dans: J. Mater. Chem. A, 7 , p. 16777–16784, 2019. @article{Ruiz-Carretero2019, title = {Charge transport enhancement in supramolecular oligothiophene assemblies using Pt(II) centers as a guide}, author = {A. Ruiz-Carretero and Y. Atoini and T. Han and A. Operamolla and S. Ippolito and C. Valentini and S. Carrara and S. Sinn and E. A. Prasetyanto and T. Heiser and P. Samorì and G. Farinola and L. De Cola}, editor = {RSC}, url = {https://doi.org/10.1039/c9ta04364k}, year = {2019}, date = {2019-06-20}, journal = {J. Mater. Chem. A}, volume = {7}, pages = {16777–16784}, abstract = {The self-assembly behaviour of platinum(II) neutral complexes has been explored in derivatives exposing oligothiophene substituents in order to organize the semiconducting units in ordered supramolecular structures. The morphology and the photophysical properties of the assemblies were studied by scanning electron microscopy, powder X-ray diffraction and photoluminescence techniques, and correlated to their charge transport properties measured in space-charge-limited current (SCLC) devices. The nature of the intermolecular Pt⋯Pt and/or π–π stacking interactions in the different supramolecular structures and in particular the inter-chromophoric distance were found to affect the hole mobility values estimated for the various semiconducting thiophene-based assemblies. The thiophene-containing architectures exhibit enhanced mobility values compared to the free ligand based ones. These results demonstrate that the supramolecular organization strategy can be applied to generate semiconducting materials via exquisite control over the arrangement of simple conjugated segments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The self-assembly behaviour of platinum(II) neutral complexes has been explored in derivatives exposing oligothiophene substituents in order to organize the semiconducting units in ordered supramolecular structures. The morphology and the photophysical properties of the assemblies were studied by scanning electron microscopy, powder X-ray diffraction and photoluminescence techniques, and correlated to their charge transport properties measured in space-charge-limited current (SCLC) devices. The nature of the intermolecular Pt⋯Pt and/or π–π stacking interactions in the different supramolecular structures and in particular the inter-chromophoric distance were found to affect the hole mobility values estimated for the various semiconducting thiophene-based assemblies. The thiophene-containing architectures exhibit enhanced mobility values compared to the free ligand based ones. These results demonstrate that the supramolecular organization strategy can be applied to generate semiconducting materials via exquisite control over the arrangement of simple conjugated segments. |
Yao, Y; Zhang, L; Orgiu, E; Samorì, P Unconventional Nanofabrication for Supramolecular Electronics Article de journal Dans: Advanced Materials, 31 (1900599), 2019. @article{Yao2019, title = {Unconventional Nanofabrication for Supramolecular Electronics}, author = {Y. Yao and L. Zhang and E. Orgiu and P. Samorì}, editor = {Wiley Online Library }, url = {https://doi.org/10.1002/adma.201900599}, year = {2019}, date = {2019-06-06}, journal = {Advanced Materials}, volume = {31}, number = {1900599}, abstract = {The scientific effort toward achieving a full control over the correlation between structure and function in organic and polymer electronics has prompted the use of supramolecular interactions to drive the formation of highly ordered functional assemblies, which have been integrated into real devices. In the resulting field of supramolecular electronics, self‐assembly of organic semiconducting materials constitutes a powerful tool to generate low‐dimensional and crystalline functional architectures. These include 1D nanostructures (nanoribbons, nanotubes, and nanowires) and 2D molecular crystals with tuneable and unique optical, electronic, and mechanical properties. Optimizing the (opto)electronic properties of organic semiconducting materials is imperative to harness such supramolecular structures as active components for supramolecular electronics. However, their integration in real devices currently represents a significant challenge to the advancement of (opto)electronics. Here, an overview of the unconventional nanofabrication techniques and device configurations to enable supramolecular electronics to become a real technology is provided. A particular focus is put on how single and multiple supramolecular fibers and gels as well as supramolecularly engineered 2D materials can be integrated into novel vertical or horizontal junctions to realize flexible and high‐density multifunctional transistors, photodetectors, and memristors, exhibiting a set of new properties and excelling in their performances.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The scientific effort toward achieving a full control over the correlation between structure and function in organic and polymer electronics has prompted the use of supramolecular interactions to drive the formation of highly ordered functional assemblies, which have been integrated into real devices. In the resulting field of supramolecular electronics, self‐assembly of organic semiconducting materials constitutes a powerful tool to generate low‐dimensional and crystalline functional architectures. These include 1D nanostructures (nanoribbons, nanotubes, and nanowires) and 2D molecular crystals with tuneable and unique optical, electronic, and mechanical properties. Optimizing the (opto)electronic properties of organic semiconducting materials is imperative to harness such supramolecular structures as active components for supramolecular electronics. However, their integration in real devices currently represents a significant challenge to the advancement of (opto)electronics. Here, an overview of the unconventional nanofabrication techniques and device configurations to enable supramolecular electronics to become a real technology is provided. A particular focus is put on how single and multiple supramolecular fibers and gels as well as supramolecularly engineered 2D materials can be integrated into novel vertical or horizontal junctions to realize flexible and high‐density multifunctional transistors, photodetectors, and memristors, exhibiting a set of new properties and excelling in their performances. |
Witomska, S; Leydecker, T; Ciesielski, A; Samorì, P Production and Patterning of Liquid Phase–Exfoliated 2D Sheets for Applications in Optoelectronics Article de journal Dans: Advanced Functional Materials, 29 (1901126), 2019. @article{Witomska2019, title = {Production and Patterning of Liquid Phase–Exfoliated 2D Sheets for Applications in Optoelectronics}, author = {S. Witomska and T. Leydecker and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library }, url = {https://doi.org/10.1002/adfm.201901126}, year = {2019}, date = {2019-05-31}, journal = {Advanced Functional Materials}, volume = {29}, number = {1901126}, abstract = {2D materials (2DMs), which can be produced by exfoliating bulk crystals of layered materials, display unique optical and electrical properties, making them attractive components for a wide range of technological applications. This review describes the most recent developments in the production of high‐quality 2DMs based inks using liquid‐phase exfoliation (LPE), combined with the patterning approaches, highlighting convenient and effective methods for generating materials and films with controlled thicknesses down to the atomic scale. Different processing strategies that can be employed to deposit the produced inks as patterns and functional thin‐films are introduced, by focusing on those that can be easily translated to the industrial scale such as coating, spraying, and various printing technologies. By providing insight into the multiscale analyses of numerous physical and chemical properties of these functional films and patterns, with a specific focus on their extraordinary electronic characteristics, this review offers the readers crucial information for a profound understanding of the fundamental properties of these patterned surfaces as the millstone toward the generation of novel multifunctional devices. Finally, the challenges and opportunities associated to the 2DMs' integration into working opto‐electronic (nano)devices is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 2D materials (2DMs), which can be produced by exfoliating bulk crystals of layered materials, display unique optical and electrical properties, making them attractive components for a wide range of technological applications. This review describes the most recent developments in the production of high‐quality 2DMs based inks using liquid‐phase exfoliation (LPE), combined with the patterning approaches, highlighting convenient and effective methods for generating materials and films with controlled thicknesses down to the atomic scale. Different processing strategies that can be employed to deposit the produced inks as patterns and functional thin‐films are introduced, by focusing on those that can be easily translated to the industrial scale such as coating, spraying, and various printing technologies. By providing insight into the multiscale analyses of numerous physical and chemical properties of these functional films and patterns, with a specific focus on their extraordinary electronic characteristics, this review offers the readers crucial information for a profound understanding of the fundamental properties of these patterned surfaces as the millstone toward the generation of novel multifunctional devices. Finally, the challenges and opportunities associated to the 2DMs' integration into working opto‐electronic (nano)devices is discussed. |
Galanti, A; Santoro, J; Mannancherry, R; Duez, Q; Diez-Cabanes, V; Valášek, M; Winter, De J; Cornil, J; Gerbaux, P; Mayor, M; Samorì, P A New Class of Rigid Multi(azobenzene) Switches Featuring Electronic Decoupling: Unravelling the Isomerization in Individual Photochromes Article de journal Dans: American Chemical Society, 141 , p. 9273−9283, 2019. @article{Galanti2019, title = {A New Class of Rigid Multi(azobenzene) Switches Featuring Electronic Decoupling: Unravelling the Isomerization in Individual Photochromes}, author = {A. Galanti and J. Santoro and R. Mannancherry and Q. Duez and V. Diez-Cabanes and M. Valášek and J. De Winter and J. Cornil and P. Gerbaux and M. Mayor and P. Samorì}, editor = {American Chemical Society}, url = {https://doi.org/10.1021/jacs.9b02544}, year = {2019}, date = {2019-05-15}, journal = {American Chemical Society}, volume = {141}, pages = {9273−9283}, abstract = {We report a novel class of star-shaped multiazobenzene photoswitches comprising individual photochromes connected to a central trisubstituted 1,3,5-benzene core. The unique design of such C3-symmetric molecules, consisting of conformationally rigid and pseudoplanar scaffolds, made it possible to explore the role of electronic decoupling in the isomerization of the individual azobenzene units. The design of our tris-, bis-, and mono(azobenzene) compounds limits the π-conjugation between the switches belonging to the same molecule, thus enabling the efficient and independent isomerization of each photochrome. An in-depth experimental insight by making use of different complementary techniques such as UV–vis absorption spectroscopy, high performance liquid chromatography, and advanced mass spectrometry methods as ion mobility revealed an almost complete absence of electronic delocalization. Such evidence was further supported by both experimental (electrochemistry, kinetical analysis) and theoretical (DFT calculations) analyses. The electronic decoupling provided by this molecular design guarantees a remarkably efficient photoswitching of all azobenzenes, as evidenced by their photoisomerization quantum yields, as well as by the Z-rich UV photostationary states. Ion mobility mass spectrometry was exploited for the first time to study multiphotochromic compounds revealing the occurrence of a large molecular shape change in such rigid star-shaped azobenzene derivatives. In view of their high structural rigidity and efficient isomerization, our multiazobenzene photoswitches can be used as key components for the fabrication of complex stimuli-responsive porous materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report a novel class of star-shaped multiazobenzene photoswitches comprising individual photochromes connected to a central trisubstituted 1,3,5-benzene core. The unique design of such C3-symmetric molecules, consisting of conformationally rigid and pseudoplanar scaffolds, made it possible to explore the role of electronic decoupling in the isomerization of the individual azobenzene units. The design of our tris-, bis-, and mono(azobenzene) compounds limits the π-conjugation between the switches belonging to the same molecule, thus enabling the efficient and independent isomerization of each photochrome. An in-depth experimental insight by making use of different complementary techniques such as UV–vis absorption spectroscopy, high performance liquid chromatography, and advanced mass spectrometry methods as ion mobility revealed an almost complete absence of electronic delocalization. Such evidence was further supported by both experimental (electrochemistry, kinetical analysis) and theoretical (DFT calculations) analyses. The electronic decoupling provided by this molecular design guarantees a remarkably efficient photoswitching of all azobenzenes, as evidenced by their photoisomerization quantum yields, as well as by the Z-rich UV photostationary states. Ion mobility mass spectrometry was exploited for the first time to study multiphotochromic compounds revealing the occurrence of a large molecular shape change in such rigid star-shaped azobenzene derivatives. In view of their high structural rigidity and efficient isomerization, our multiazobenzene photoswitches can be used as key components for the fabrication of complex stimuli-responsive porous materials. |
Zhao, Y; Ippolito, S; Samorì, P Functionalization of 2D Materials with Photosensitive Molecules: From Light‐Responsive Hybrid Systems to Multifunctional Devices Article de journal Dans: Advanced Optical Materials, 7 , p. 1900286, 2019. @article{Zhao2019b, title = {Functionalization of 2D Materials with Photosensitive Molecules: From Light‐Responsive Hybrid Systems to Multifunctional Devices}, author = {Y. Zhao and S. Ippolito and P. Samorì}, editor = {Wiley}, url = {https://doi.org/10.1002/adom.201900286}, year = {2019}, date = {2019-05-12}, journal = {Advanced Optical Materials}, volume = {7}, pages = {1900286}, abstract = {2D materials possess exceptional physical and chemical properties that render them appealing components for numerous potential applications in (opto)electronics, energy storage, sensing, and biomedicine. However, such unique properties are hardly tunable or modifiable. The functionalization of 2D crystals with molecules constitutes a powerful strategy to adjust and modulate their properties, by also imparting them new functions. In this framework, the combination of 2D materials with photosensitive molecules is a viable route for harnessing their light‐responsive nature. The latter takes full advantage of the extremely high sensitivity of 2D materials to subtle changes in the local environment and the capacity of photosensitive molecules to modify their intrinsic properties when exposed to electromagnetic fields. The hybrid molecule–2D materials can preserve the unique optical and electrical properties of 2D layers and can exhibit additional light‐tunable features. In this Progress Report, the protocols that can be pursued for the 2D material functionalization and switching mechanisms in photosensitive systems are reviewed, followed by an in‐depth discussion on their tunable optical properties and their exploitation when integrated in novel photoswitchable electronic devices. The opportunities and associated challenges to be tackled for the development of unprecedented and high‐performance light‐responsive devices are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 2D materials possess exceptional physical and chemical properties that render them appealing components for numerous potential applications in (opto)electronics, energy storage, sensing, and biomedicine. However, such unique properties are hardly tunable or modifiable. The functionalization of 2D crystals with molecules constitutes a powerful strategy to adjust and modulate their properties, by also imparting them new functions. In this framework, the combination of 2D materials with photosensitive molecules is a viable route for harnessing their light‐responsive nature. The latter takes full advantage of the extremely high sensitivity of 2D materials to subtle changes in the local environment and the capacity of photosensitive molecules to modify their intrinsic properties when exposed to electromagnetic fields. The hybrid molecule–2D materials can preserve the unique optical and electrical properties of 2D layers and can exhibit additional light‐tunable features. In this Progress Report, the protocols that can be pursued for the 2D material functionalization and switching mechanisms in photosensitive systems are reviewed, followed by an in‐depth discussion on their tunable optical properties and their exploitation when integrated in novel photoswitchable electronic devices. The opportunities and associated challenges to be tackled for the development of unprecedented and high‐performance light‐responsive devices are discussed. |
Samorì, P; Biscarini, F Interface Engineering in Organic Devices Article de journal Dans: Advanced Materials Technologies, 4 (1900303), 2019. @article{Samorì2019, title = {Interface Engineering in Organic Devices}, author = {P. Samorì and F. Biscarini}, editor = {Wiley Online Library }, url = {https://doi.org/10.1002/admt.201900303}, year = {2019}, date = {2019-05-10}, journal = {Advanced Materials Technologies}, volume = {4}, number = {1900303}, abstract = {Interfaces are ubiquitous in nature and play a key role in many fundamental physical and chemical processes. In organic electronic devices, where charge injection, charge transport, and trapping are indeed interfacial phenomena, the intrinsic properties of the active materials, their processability and their response in devices can be modulated and even disguised by mismatched interfacial properties, sometimes hampering the concept of “properties by molecular design” which is one of the pillars of organic electronics. Tailoring the interface and thus achieving full control over their properties in fabrication processes of organic devices, and optimizing them for device response, is technologically challenging due to the intertwining of complex phenomena during the assembly of molecular and supramolecular architectures on technological surfaces. Examples include the control of molecular orientation, nucleation and growth of molecularly ordered domains which affect the surface roughness and lateral morphological correlations, as well as the coexistence of misoriented crystalline domains, their size distribution and the extent of domain boundaries. Dynamic processes such as wetting, dewetting and ripening govern the occurrence of (re‐)crystallization yielding the formation of inhomogeneous thin films on specific length scales during the device fabrication, and can also be subjected to re‐adjustment while the device is “in‐action” thereby affecting its time‐stability. From the more functional viewpoint, the boosting of charge injection can be attained via the optimization of energy level alignment and the minimization of energy barriers through the physisorption or chemisorption of suitably designed molecular building blocks. Moreover, density of charged surface states, (local) doping and trapping can be modulated via non‐covalent surface interactions. The bottom‐up engineering of the physical chemistry of the interfaces is an effective approach towards the multiscale control of supramolecular organization and energy (dis‐)order of the device interfaces, such as organic/dielectric, organic/electrode, organic/organic, and organic/ambient. The approach is also central to the design of chemo‐ and biosensors, as it endows them with sensitivity and selectivity towards specific analytes. Interface engineering has to be regarded, therefore, as an enabling strategy for achieving unprecedented multifunctional and multi‐responsive organic devices with full control over the correlation between structure and function. This special section of Advanced Materials Technologies reports a few enlightening recent experimental and chemical‐design approaches aimed at controlling and tuning some technologically relevant interfacial properties in organic devices, including field‐effect transistors, solar cells and light‐emitting diodes. We briefly overview below the five contributions to this special section, sorting them according to a logical sequence, from charge‐injection interfaces, to transport‐layer interfaces, to novel low‐dimensional architectures for organic devices. Work function modification is the central topic of the article by V. Diez‐Cabanes and co‐workers, as a joint collaboration between Université de Mons (Belgium), ICMAB‐CSIC and CIBER‐BBN Barcelona (Spain), Università di Parma (Italy), and Universidad de Ambato (Ecuador). Self‐assembling monolayers (SAMs) are a vastly explored topic both experimentally and theoretically in organic electronics devices, and SAMs are already consolidated in the manufacturing technology of organic devices. Here the authors report a not‐so well investigated effect, viz. the role of molecular polarizability of SAMs on the work function modification of Au electrodes, and in particular, using a donor‐acceptor paradigmatic dyad, ferrocene (D) and PCTM radical (A), they rationalize the effect of charge transfer and spin states on determining the work function and level alignment at the charge injection interface, also suggesting routes for tailoring the work function shift. The article by F. Hermerschmidt, S. A. Choulis, and E. J. W. List‐Kratochvil from Humboldt Universität Berlin (Germany) addresses a nowadays relevant technological problem which is the availability, processing and replacement of ITO in conductive transparent electrodes for optoelectronics applications such as OPV and OLED. The authors discuss the potential of the use of metal nanoparticles that are inkjet‐printed, how to process them to control conductivity and interfacial properties, to show how the manufacturing of organic optoelectronics devices can be aligned to a whole‐additive printing platform. The article by Weining Zhang, Hongliang Chen, and Xuefeng Guo, from Peking University (China) reviews the recent developments and challenges of interface‐engineered organic optoelectronic devices for future applications in electronics and optoelectronics. They emphasize the control of interfacial charge transport for building functional optoelectronic devices, by means of the finest control of individual layers of materials and their interfaces in devices, to design functional transistors, biodetection devices, and flexible electronics, as well as other types of traditional optoelectronic devices, such as photodetectors, photovoltaic devices, and light‐emitting devices, with unprecedented characteristics or unique functionalities. The group of Yun Li from Nanjing University (China) presents an overview of the technology of field‐effect transistors based on solution‐processed two‐dimensional molecular crystals (2DMCs), as a route to overcome the limits in the charge transport properties imposed by the heterogenous nature of active layers and thin films. They highlight the present capability of upscaled manufacturing of OFETs with 2DMCs, which shows how the field has moved in recent years from the very fundamental field of organic single crystals for studies of the transport physics, towards an enabling technology that may lead to high performance back‐end panels and logic circuits that consumer electronics requires. The contribution by Zhengbang Wang and Christof Wöll from Karlsruhe Institute of Technology (KIT) (Germany) introduces an emerging class of low‐dimensional nanomaterials, metal‐organic frameworks (MOFs), that are encountering the interest of materials scientists for the next generation of hybrid organic/inorganic optoelectronics, photonics and sensing devices. In particular, the authors discuss the approach to MOFs based on the programmed layer‐by‐layer assembly technique, which enables exquisite control over the MOF architecture on surfaces (SURMOFs) across large areas and with very high control of order and orientation. The relevant properties and device applications are finally reviewed. This special section well reflects the breadth of this burgeoning and interdisciplinary field of science, which holds great potential for technological breakthroughs. We hope the readers of Advanced Materials Technologies find these contributions inspiring in terms of the importance of devising novel approaches, based on both knowledge and chemical creativity, for the technology of organic devices. With best regards, Paolo Samorì & Fabio Biscarini (Guest Editors) Biographies Paolo Samorì is Distinguished Professor at the Université de Strasbourg, Director of the Institut de Science et d'Ingénierie Supramoléculaires (ISIS). He obtained a Laurea at University of Bologna and his PhD at the Humboldt University of Berlin. He was permanent research scientist at Istituto per la Sintesi Organica e la Fotoreattività of the Consiglio Nazionale delle Ricerche of Bologna. His research interests encompass nanochemistry, supramolecular sciences, materials chemistry, and scanning probe microscopies with a specific focus on graphene and other 2D materials as well as functional organic/polymeric and hybrid nanomaterials for application in optoelectronics, energy and sensing. image Fabio Biscarini is Full Professor of General Chemistry and Nanobiotechnology in the Life Sciences Department, Università di Modena e Reggio Emilia since 2013. From 2017 he is Research Associate at Istituto Italiano di Tecnologia (IIT)‐Center for Translational Neurosciences in Ferrara, where he heads the Organic Neuroelectronics team. He graduated in Industrial Chemistry at Università di Bologna (1986), received a PhD in Chemistry at University of Oregon (1993), and was postdoc (1994–1995) at Consiglio Nazionale delle Ricerche (CNR) Bologna, where became Research Scientist (1994–2000), Senior Scientist (2001–2010), and Research Director (2010–2013). His current research interests are in fundamental aspects of organic bioelectronics, biosensors, and implantable devices for bidirectional communication with the central nervous system. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Interfaces are ubiquitous in nature and play a key role in many fundamental physical and chemical processes. In organic electronic devices, where charge injection, charge transport, and trapping are indeed interfacial phenomena, the intrinsic properties of the active materials, their processability and their response in devices can be modulated and even disguised by mismatched interfacial properties, sometimes hampering the concept of “properties by molecular design” which is one of the pillars of organic electronics. Tailoring the interface and thus achieving full control over their properties in fabrication processes of organic devices, and optimizing them for device response, is technologically challenging due to the intertwining of complex phenomena during the assembly of molecular and supramolecular architectures on technological surfaces. Examples include the control of molecular orientation, nucleation and growth of molecularly ordered domains which affect the surface roughness and lateral morphological correlations, as well as the coexistence of misoriented crystalline domains, their size distribution and the extent of domain boundaries. Dynamic processes such as wetting, dewetting and ripening govern the occurrence of (re‐)crystallization yielding the formation of inhomogeneous thin films on specific length scales during the device fabrication, and can also be subjected to re‐adjustment while the device is “in‐action” thereby affecting its time‐stability. From the more functional viewpoint, the boosting of charge injection can be attained via the optimization of energy level alignment and the minimization of energy barriers through the physisorption or chemisorption of suitably designed molecular building blocks. Moreover, density of charged surface states, (local) doping and trapping can be modulated via non‐covalent surface interactions. The bottom‐up engineering of the physical chemistry of the interfaces is an effective approach towards the multiscale control of supramolecular organization and energy (dis‐)order of the device interfaces, such as organic/dielectric, organic/electrode, organic/organic, and organic/ambient. The approach is also central to the design of chemo‐ and biosensors, as it endows them with sensitivity and selectivity towards specific analytes. Interface engineering has to be regarded, therefore, as an enabling strategy for achieving unprecedented multifunctional and multi‐responsive organic devices with full control over the correlation between structure and function. This special section of Advanced Materials Technologies reports a few enlightening recent experimental and chemical‐design approaches aimed at controlling and tuning some technologically relevant interfacial properties in organic devices, including field‐effect transistors, solar cells and light‐emitting diodes. We briefly overview below the five contributions to this special section, sorting them according to a logical sequence, from charge‐injection interfaces, to transport‐layer interfaces, to novel low‐dimensional architectures for organic devices. Work function modification is the central topic of the article by V. Diez‐Cabanes and co‐workers, as a joint collaboration between Université de Mons (Belgium), ICMAB‐CSIC and CIBER‐BBN Barcelona (Spain), Università di Parma (Italy), and Universidad de Ambato (Ecuador). Self‐assembling monolayers (SAMs) are a vastly explored topic both experimentally and theoretically in organic electronics devices, and SAMs are already consolidated in the manufacturing technology of organic devices. Here the authors report a not‐so well investigated effect, viz. the role of molecular polarizability of SAMs on the work function modification of Au electrodes, and in particular, using a donor‐acceptor paradigmatic dyad, ferrocene (D) and PCTM radical (A), they rationalize the effect of charge transfer and spin states on determining the work function and level alignment at the charge injection interface, also suggesting routes for tailoring the work function shift. The article by F. Hermerschmidt, S. A. Choulis, and E. J. W. List‐Kratochvil from Humboldt Universität Berlin (Germany) addresses a nowadays relevant technological problem which is the availability, processing and replacement of ITO in conductive transparent electrodes for optoelectronics applications such as OPV and OLED. The authors discuss the potential of the use of metal nanoparticles that are inkjet‐printed, how to process them to control conductivity and interfacial properties, to show how the manufacturing of organic optoelectronics devices can be aligned to a whole‐additive printing platform. The article by Weining Zhang, Hongliang Chen, and Xuefeng Guo, from Peking University (China) reviews the recent developments and challenges of interface‐engineered organic optoelectronic devices for future applications in electronics and optoelectronics. They emphasize the control of interfacial charge transport for building functional optoelectronic devices, by means of the finest control of individual layers of materials and their interfaces in devices, to design functional transistors, biodetection devices, and flexible electronics, as well as other types of traditional optoelectronic devices, such as photodetectors, photovoltaic devices, and light‐emitting devices, with unprecedented characteristics or unique functionalities. The group of Yun Li from Nanjing University (China) presents an overview of the technology of field‐effect transistors based on solution‐processed two‐dimensional molecular crystals (2DMCs), as a route to overcome the limits in the charge transport properties imposed by the heterogenous nature of active layers and thin films. They highlight the present capability of upscaled manufacturing of OFETs with 2DMCs, which shows how the field has moved in recent years from the very fundamental field of organic single crystals for studies of the transport physics, towards an enabling technology that may lead to high performance back‐end panels and logic circuits that consumer electronics requires. The contribution by Zhengbang Wang and Christof Wöll from Karlsruhe Institute of Technology (KIT) (Germany) introduces an emerging class of low‐dimensional nanomaterials, metal‐organic frameworks (MOFs), that are encountering the interest of materials scientists for the next generation of hybrid organic/inorganic optoelectronics, photonics and sensing devices. In particular, the authors discuss the approach to MOFs based on the programmed layer‐by‐layer assembly technique, which enables exquisite control over the MOF architecture on surfaces (SURMOFs) across large areas and with very high control of order and orientation. The relevant properties and device applications are finally reviewed. This special section well reflects the breadth of this burgeoning and interdisciplinary field of science, which holds great potential for technological breakthroughs. We hope the readers of Advanced Materials Technologies find these contributions inspiring in terms of the importance of devising novel approaches, based on both knowledge and chemical creativity, for the technology of organic devices. With best regards, Paolo Samorì & Fabio Biscarini (Guest Editors) Biographies Paolo Samorì is Distinguished Professor at the Université de Strasbourg, Director of the Institut de Science et d'Ingénierie Supramoléculaires (ISIS). He obtained a Laurea at University of Bologna and his PhD at the Humboldt University of Berlin. He was permanent research scientist at Istituto per la Sintesi Organica e la Fotoreattività of the Consiglio Nazionale delle Ricerche of Bologna. His research interests encompass nanochemistry, supramolecular sciences, materials chemistry, and scanning probe microscopies with a specific focus on graphene and other 2D materials as well as functional organic/polymeric and hybrid nanomaterials for application in optoelectronics, energy and sensing. image Fabio Biscarini is Full Professor of General Chemistry and Nanobiotechnology in the Life Sciences Department, Università di Modena e Reggio Emilia since 2013. From 2017 he is Research Associate at Istituto Italiano di Tecnologia (IIT)‐Center for Translational Neurosciences in Ferrara, where he heads the Organic Neuroelectronics team. He graduated in Industrial Chemistry at Università di Bologna (1986), received a PhD in Chemistry at University of Oregon (1993), and was postdoc (1994–1995) at Consiglio Nazionale delle Ricerche (CNR) Bologna, where became Research Scientist (1994–2000), Senior Scientist (2001–2010), and Research Director (2010–2013). His current research interests are in fundamental aspects of organic bioelectronics, biosensors, and implantable devices for bidirectional communication with the central nervous system. |
Muchowska, Kamila B; Varma, Sreejith J; Moran, Joseph Synthesis and breakdown of universal metabolic precursors promoted by iron Article de journal Dans: Nature, 569 , p. 104-107, 2019. @article{Muchowska2019, title = {Synthesis and breakdown of universal metabolic precursors promoted by iron}, author = {Kamila B. Muchowska and Sreejith J. Varma and Joseph Moran }, editor = {Nature}, url = {https://www.nature.com/articles/s41586-019-1151-1}, doi = {10.1038/s41586-019-1151-1}, year = {2019}, date = {2019-05-01}, journal = {Nature}, volume = {569}, pages = {104-107}, abstract = {Life builds its molecules from carbon dioxide (CO2) and breaks them back down again through the intermediacy of just five metabolites, which are the universal hubs of biochemistry1. However, it is unclear how core biological metabolism began and why it uses the intermediates, reactions and pathways that it does. Here we describe a purely chemical reaction network promoted by ferrous iron, in which aqueous pyruvate and glyoxylate—two products of abiotic CO2 reduction2,3,4—build up 9 of the 11 intermediates of the biological Krebs (or tricarboxylic acid) cycle, including all 5 universal metabolic precursors. The intermediates simultaneously break down to CO2 in a life-like regime that resembles biological anabolism and catabolism5. Adding hydroxylamine6,7,8 and metallic iron into the system produces four biological amino acids in a manner that parallels biosynthesis. The observed network overlaps substantially with the Krebs and glyoxylate cycles9,10, and may represent a prebiotic precursor to these core metabolic pathways.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Life builds its molecules from carbon dioxide (CO2) and breaks them back down again through the intermediacy of just five metabolites, which are the universal hubs of biochemistry1. However, it is unclear how core biological metabolism began and why it uses the intermediates, reactions and pathways that it does. Here we describe a purely chemical reaction network promoted by ferrous iron, in which aqueous pyruvate and glyoxylate—two products of abiotic CO2 reduction2,3,4—build up 9 of the 11 intermediates of the biological Krebs (or tricarboxylic acid) cycle, including all 5 universal metabolic precursors. The intermediates simultaneously break down to CO2 in a life-like regime that resembles biological anabolism and catabolism5. Adding hydroxylamine6,7,8 and metallic iron into the system produces four biological amino acids in a manner that parallels biosynthesis. The observed network overlaps substantially with the Krebs and glyoxylate cycles9,10, and may represent a prebiotic precursor to these core metabolic pathways. |
Travaglini, Leana ; Picchetti, Pierre ; Del Giudice, Alessandra ; Galantini, Luciano ; De Cola, Luisa Tuning and controlling the shape of mesoporous silica particles with CTAB/sodium deoxycholate catanionic mixtures Article de journal Dans: MICROPOROUS AND MESOPOROUS MATERIALS, 279 , p. 423-431, 2019. @article{Travaglini2019, title = {Tuning and controlling the shape of mesoporous silica particles with CTAB/sodium deoxycholate catanionic mixtures}, author = {Travaglini, Leana and Picchetti, Pierre and Del Giudice, Alessandra and Galantini, Luciano and De Cola, Luisa}, editor = {MICROPOROUS AND MESOPOROUS MATERIALS}, doi = {10.1016/j.micromeso.2019.01.030}, year = {2019}, date = {2019-05-01}, journal = {MICROPOROUS AND MESOPOROUS MATERIALS}, volume = {279 }, pages = {423-431}, abstract = {Controlling the shape and size of mesoporous silica particles (MSPs) requires a deep understanding of the different parameters that play a major role during the synthesis of the materials. One of the key factors that can determine the morphology and porosity of the systems is the surfactant, used as a templating agent. We have very recently proven that binary mixtures of hexadecyltrimethylammonium bromide (CTAB) and bile salts are templating systems effective in controlling the morphology of MSPs in a facile and non-costly way. In this work we investigated the effect of different surfactant ratios in order to gain deeper insights on the influence of these catanionic mixtures on particle morphology. We employed mixtures of CTAB and sodium deoxycholate (NaDC) and upon variation of a sole parameter, the NaDC concentration, we achieved shape tuning. Hexagonal platelets, rods, oblate and toroidal particles were obtained and fully characterized. Moreover, investigation of the CTAB/ NaDC assemblies showed that the morphology tuning is related to the evolution of the mixed micelles properties, occurring upon variation of the surfactant ratio.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Controlling the shape and size of mesoporous silica particles (MSPs) requires a deep understanding of the different parameters that play a major role during the synthesis of the materials. One of the key factors that can determine the morphology and porosity of the systems is the surfactant, used as a templating agent. We have very recently proven that binary mixtures of hexadecyltrimethylammonium bromide (CTAB) and bile salts are templating systems effective in controlling the morphology of MSPs in a facile and non-costly way. In this work we investigated the effect of different surfactant ratios in order to gain deeper insights on the influence of these catanionic mixtures on particle morphology. We employed mixtures of CTAB and sodium deoxycholate (NaDC) and upon variation of a sole parameter, the NaDC concentration, we achieved shape tuning. Hexagonal platelets, rods, oblate and toroidal particles were obtained and fully characterized. Moreover, investigation of the CTAB/ NaDC assemblies showed that the morphology tuning is related to the evolution of the mixed micelles properties, occurring upon variation of the surfactant ratio. |
Aliprandi, A; Eredia, M; Anichini, C; Baaziz, W; Ersen, O; Ciesielski, A; Samorì, P Persian waxing of graphite: towards green large-scale production of graphene Article de journal Dans: Chem. Commun 2019, 55 , p. 5331-5334, 2019. @article{Aliprandi2019, title = {Persian waxing of graphite: towards green large-scale production of graphene}, author = {A. Aliprandi and M. Eredia and C. Anichini and W. Baaziz and O. Ersen and A. Ciesielski and P. Samorì}, doi = {10.1039/c9cc01822k}, year = {2019}, date = {2019-04-04}, journal = {Chem. Commun 2019}, volume = {55}, pages = {5331-5334}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Guasch, J; Crivillers, N; Souto, M; Ratera, I; Rovira, C; Samorì, P; Veciana, J Two-dimensional self-assembly and electrical properties of the donor-acceptor tetrathiafulvalene-polychlorotriphenylmethyl radical on graphite substrates Article de journal Dans: Journal of Applied Physics, 125 (142909), 2019. @article{Guasch2019, title = {Two-dimensional self-assembly and electrical properties of the donor-acceptor tetrathiafulvalene-polychlorotriphenylmethyl radical on graphite substrates}, author = {J. Guasch and N. Crivillers and M. Souto and I. Ratera and C. Rovira and P. Samorì and J. Veciana}, editor = {AIP }, url = {https://aip.scitation.org/doi/abs/10.1063/1.5065448}, doi = {10.1063/1.5065448}, year = {2019}, date = {2019-04-02}, journal = {Journal of Applied Physics}, volume = {125}, number = {142909}, abstract = {The electron donor-acceptor tetrathiafulvalene-polychlorotriphenylmethyl (PTM) radical dyad, which shows a strong interplay between intra- and intermolecular charge transfer processes in solution, has been deposited by drop-casting on highly oriented pyrolytic graphite substrates, and its self-assembled structure has been investigated. Conducting atomic force microscopy revealed that the presence of a PTM radical in the molecules enhances the electrical conduction by almost two orders of magnitude and that this enhancement occurs in spite of the poor molecular orientation control achieved with drop-casting. Moreover, the study also reveals that the presence of a tetrathiafulvalene subunit in the deposited molecules can result in slightly asymmetric I-V curves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The electron donor-acceptor tetrathiafulvalene-polychlorotriphenylmethyl (PTM) radical dyad, which shows a strong interplay between intra- and intermolecular charge transfer processes in solution, has been deposited by drop-casting on highly oriented pyrolytic graphite substrates, and its self-assembled structure has been investigated. Conducting atomic force microscopy revealed that the presence of a PTM radical in the molecules enhances the electrical conduction by almost two orders of magnitude and that this enhancement occurs in spite of the poor molecular orientation control achieved with drop-casting. Moreover, the study also reveals that the presence of a tetrathiafulvalene subunit in the deposited molecules can result in slightly asymmetric I-V curves. |
Zhao, Yuda; Bertolazzi, Simone; Samorì, Paolo A Universal Approach toward Light-Responsive Two-Dimensional Electronics: Chemically Tailored Hybrid van der Waals Heterostructures Article de journal Dans: ACS Nano 2019, 13 (4), p. 4814-4825, 2019. @article{Zhao2019, title = {A Universal Approach toward Light-Responsive Two-Dimensional Electronics: Chemically Tailored Hybrid van der Waals Heterostructures}, author = {Yuda Zhao and Simone Bertolazzi and Paolo Samorì}, editor = {2019 American Chemical Society}, url = {https://pubs.acs.org/doi/pdf/10.1021/acsnano.9b01716}, doi = {10.1021/acsnano.9b01716}, year = {2019}, date = {2019-03-27}, journal = {ACS Nano 2019}, volume = {13}, number = {4}, pages = {4814-4825}, abstract = {Stimuli-responsive hybrid van der Waals heterostructures (vdWHs), composed of organic molecular switches superimposed on inorganic 2D materials (2DMs), can combine the outstanding physical properties of the latter components with the virtually infinite variety of tunable functionality of molecules, thereby offering an efficient protocol for the development of high-performance multifunctional materials and devices. The use of light as a remote control to modulate the properties of semiconducting 2DMs when interfaced with photochromic molecules suffers from both the limitation associated with the persistent photoconductivity characterizing the 2DMs and the finite thermal stability of the photochromic molecule in its different states. Here, we have devised a universal approach toward the fabrication of optically switchable electronic devices comprising a few nanometers thick azobenzene (AZO) layer physisorbed on 2D semiconductors supported on a trap-free polymer dielectric. The joint effect of the improved 2D/dielectric interface, the molecule’s light-modulated dipolar doping, and the high thermal stability of cis-AZO offers the highest control over the reversible and efficient charge carrier tuning in 2D semiconductors with a preserved high performance in 2D field-effect transistors, as quantified in terms of carrier mobility and Ion/Ioff ratio. The device has the potential to operate as an optical memory with four current levels and long retention time (>15 h). Furthermore, by using a CMOS-compatible micropatterning process, the photoswitchable resistor–diode transition has been achieved on hybrid lateral heterojunction devices. Our approach is of general applicability toward the generation of high-performance hybrid vdWHs for the emergence of functional and responsive devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Stimuli-responsive hybrid van der Waals heterostructures (vdWHs), composed of organic molecular switches superimposed on inorganic 2D materials (2DMs), can combine the outstanding physical properties of the latter components with the virtually infinite variety of tunable functionality of molecules, thereby offering an efficient protocol for the development of high-performance multifunctional materials and devices. The use of light as a remote control to modulate the properties of semiconducting 2DMs when interfaced with photochromic molecules suffers from both the limitation associated with the persistent photoconductivity characterizing the 2DMs and the finite thermal stability of the photochromic molecule in its different states. Here, we have devised a universal approach toward the fabrication of optically switchable electronic devices comprising a few nanometers thick azobenzene (AZO) layer physisorbed on 2D semiconductors supported on a trap-free polymer dielectric. The joint effect of the improved 2D/dielectric interface, the molecule’s light-modulated dipolar doping, and the high thermal stability of cis-AZO offers the highest control over the reversible and efficient charge carrier tuning in 2D semiconductors with a preserved high performance in 2D field-effect transistors, as quantified in terms of carrier mobility and Ion/Ioff ratio. The device has the potential to operate as an optical memory with four current levels and long retention time (>15 h). Furthermore, by using a CMOS-compatible micropatterning process, the photoswitchable resistor–diode transition has been achieved on hybrid lateral heterojunction devices. Our approach is of general applicability toward the generation of high-performance hybrid vdWHs for the emergence of functional and responsive devices. |
Darmawan, Noviyan ; Sambri, Letizia ; Daniliuc, Constantin G; De Cola, Luisa Blue-emitting bolaamphiphilic zwitterionic iridium(iii) complex Article de journal Dans: DALTON TRANSACTIONS, 48 (11), p. 3664-3670 , 2019. @article{Darmawan2019, title = {Blue-emitting bolaamphiphilic zwitterionic iridium(iii) complex}, author = {Darmawan, Noviyan and Sambri, Letizia and Daniliuc, Constantin G. and De Cola, Luisa}, editor = {DALTON TRANSACTIONS}, doi = {10.1039/c8dt04833a}, year = {2019}, date = {2019-03-21}, journal = {DALTON TRANSACTIONS}, volume = {48}, number = {11}, pages = {3664-3670 }, abstract = {Aggregation induced emission is a very interesting phenomenon that recently has attracted a lot of interest. Most of the examples deal with organic molecules or flat metal complexes. Here we demonstrate that, by design, even iridium compounds can display this process without shifting the emission energy. In order to enhance the aggregation properties we have focussed on amphiphilic complexes. We report the synthesis and photophysical characterisation of a blue-emitting bolaamphiphilic zwitterionic Ir(III) complex and an analogous cationic amphiphilic compound, used as a reference. The bolaamphiphile exhibited blue (lambda(max) = 450 nm) emission in dilute, deaerated solution with a photoluminescence quantum yield (PLQY) of 22%, similar to the related cationic amphiphilic complex. The bolaamphiphile displayed significant emission enhancement in the solid state, with an emission quantum yield that reach 52%. Interestingly, the emission of the cationic analogue suffers from aggregation quenching in the solid state, (PLQY = 3%) as is common for these type of complexes. A correlation between the photophysical data and the arrangement in the solid state is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Aggregation induced emission is a very interesting phenomenon that recently has attracted a lot of interest. Most of the examples deal with organic molecules or flat metal complexes. Here we demonstrate that, by design, even iridium compounds can display this process without shifting the emission energy. In order to enhance the aggregation properties we have focussed on amphiphilic complexes. We report the synthesis and photophysical characterisation of a blue-emitting bolaamphiphilic zwitterionic Ir(III) complex and an analogous cationic amphiphilic compound, used as a reference. The bolaamphiphile exhibited blue (lambda(max) = 450 nm) emission in dilute, deaerated solution with a photoluminescence quantum yield (PLQY) of 22%, similar to the related cationic amphiphilic complex. The bolaamphiphile displayed significant emission enhancement in the solid state, with an emission quantum yield that reach 52%. Interestingly, the emission of the cationic analogue suffers from aggregation quenching in the solid state, (PLQY = 3%) as is common for these type of complexes. A correlation between the photophysical data and the arrangement in the solid state is discussed. |
Hagenmüller, David; Schachenmayer, Johannes; Genet, Cyriaque; Ebbesen, Thomas W; Pupillo, Guido Enhancement of the Electron−Phonon Scattering Induced by Intrinsic Surface Plasmon−Phonon Polaritons Article de journal Dans: ACS Photonics 2019, 6 (4), pp 1073–1081, 6 (4), p. 1073-1081, 2019. @article{Hagenmüller2019, title = {Enhancement of the Electron−Phonon Scattering Induced by Intrinsic Surface Plasmon−Phonon Polaritons}, author = {David Hagenmüller and Johannes Schachenmayer and Cyriaque Genet and Thomas W. Ebbesen and Guido Pupillo}, editor = {Copyright © 2019 American Chemical Society }, doi = {10.1021/acsphotonics.9b00268}, year = {2019}, date = {2019-03-17}, journal = {ACS Photonics 2019, 6 (4), pp 1073–1081}, volume = {6}, number = {4}, pages = {1073-1081}, abstract = {We investigate light−matter coupling in metallic crystals where plasmons coexist with phonons exhibiting large oscillator strength. We demonstrate theoretically that this coexistence can lead to strong light−matter interactions without external resonators. When the frequencies of plasmons and phonons are comparable, hybridization of these collective matter modes occurs in the crystal. We show that the coupling of these modes to photonic degrees of freedom gives rise to intrinsic surface plasmon−phonon polaritons, which offer the unique possibility to control the phonon properties by tuning the electron density and the crystal thickness. In particular, dressed phonons with reduced frequency and large wave vectors arise in the case of quasi-2D crystals, which could lead to large enhancements of the electron−phonon scattering in the vibrational ultrastrong coupling regime. This suggests that photons can play a key role in determining the quantum properties of certain materials. A nonperturbative self-consistent Hamiltonian method is presented that is valid for arbitrarily large coupling strengths.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate light−matter coupling in metallic crystals where plasmons coexist with phonons exhibiting large oscillator strength. We demonstrate theoretically that this coexistence can lead to strong light−matter interactions without external resonators. When the frequencies of plasmons and phonons are comparable, hybridization of these collective matter modes occurs in the crystal. We show that the coupling of these modes to photonic degrees of freedom gives rise to intrinsic surface plasmon−phonon polaritons, which offer the unique possibility to control the phonon properties by tuning the electron density and the crystal thickness. In particular, dressed phonons with reduced frequency and large wave vectors arise in the case of quasi-2D crystals, which could lead to large enhancements of the electron−phonon scattering in the vibrational ultrastrong coupling regime. This suggests that photons can play a key role in determining the quantum properties of certain materials. A nonperturbative self-consistent Hamiltonian method is presented that is valid for arbitrarily large coupling strengths. |
Bertolazzi, S; Bondavalli, P; Roche, S; San, T; Choi, S -Y; Colombo, L; Bonaccorso, F; Samorì, P Nonvolatile Memories Based on Graphene and Related 2D Materials Article de journal Dans: Advanced Materials, 31 (Issue 10), p. 1806663, 2019. @article{Bertolazzi2019, title = {Nonvolatile Memories Based on Graphene and Related 2D Materials}, author = {S. Bertolazzi and P. Bondavalli and S. Roche and T. San and S.-Y. Choi and L. Colombo and F. Bonaccorso and P. Samorì}, editor = {Wiley Online Library}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201806663}, doi = {10.1002/adma.201806663}, year = {2019}, date = {2019-03-08}, journal = {Advanced Materials}, volume = {31}, number = {Issue 10}, pages = {1806663}, abstract = {The pervasiveness of information technologies is generating an impressive amount of data, which need to be accessed very quickly. Nonvolatile memories (NVMs) are making inroads into high‐capacity storage to replace hard disk drives, fuelling the expansion of the global storage memory market. As silicon‐based flash memories are approaching their fundamental limit, vertical stacking of multiple memory cell layers, innovative device concepts, and novel materials are being investigated. In this context, emerging 2D materials, such as graphene, transition metal dichalcogenides, and black phosphorous, offer a host of physical and chemical properties, which could both improve existing memory technologies and enable the next generation of low‐cost, flexible, and wearable storage devices. Herein, an overview of graphene and related 2D materials (GRMs) in different types of NVM cells is provided, including resistive random‐access, flash, magnetic and phase‐change memories. The physical and chemical mechanisms underlying the switching of GRM‐based memory devices studied in the last decade are discussed. Although at this stage most of the proof‐of‐concept devices investigated do not compete with state‐of‐the‐art devices, a number of promising technological advancements have emerged. Here, the most relevant material properties and device structures are analyzed, emphasizing opportunities and challenges toward the realization of practical NVM devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The pervasiveness of information technologies is generating an impressive amount of data, which need to be accessed very quickly. Nonvolatile memories (NVMs) are making inroads into high‐capacity storage to replace hard disk drives, fuelling the expansion of the global storage memory market. As silicon‐based flash memories are approaching their fundamental limit, vertical stacking of multiple memory cell layers, innovative device concepts, and novel materials are being investigated. In this context, emerging 2D materials, such as graphene, transition metal dichalcogenides, and black phosphorous, offer a host of physical and chemical properties, which could both improve existing memory technologies and enable the next generation of low‐cost, flexible, and wearable storage devices. Herein, an overview of graphene and related 2D materials (GRMs) in different types of NVM cells is provided, including resistive random‐access, flash, magnetic and phase‐change memories. The physical and chemical mechanisms underlying the switching of GRM‐based memory devices studied in the last decade are discussed. Although at this stage most of the proof‐of‐concept devices investigated do not compete with state‐of‐the‐art devices, a number of promising technological advancements have emerged. Here, the most relevant material properties and device structures are analyzed, emphasizing opportunities and challenges toward the realization of practical NVM devices. |
Schnoering, Gabriel; Rosales-Cabara, Yoseline; Wendehenne, Hugo; Canaguier-Durand, Antoine; Genet, Cyriaque Thermally Limited Force Microscopy on Optically Trapped Single Metallic Nanoparticles Article de journal Dans: PHYSICAL REVIEW APPLIED , 11 ( 034023), 2019. @article{Schnoering2019, title = {Thermally Limited Force Microscopy on Optically Trapped Single Metallic Nanoparticles}, author = {Gabriel Schnoering and Yoseline Rosales-Cabara and Hugo Wendehenne and Antoine Canaguier-Durand and Cyriaque Genet}, editor = {© 2019 American Physical Society}, doi = {DOI: 10.1103/PhysRevApplied.11.034023}, year = {2019}, date = {2019-03-08}, journal = {PHYSICAL REVIEW APPLIED }, volume = {11}, number = { 034023}, abstract = {We propose and evaluate a new type of optical force microscope based on a standing-wave optical trap. Our microscope, calibrated in situ and operating in a dynamic mode, is able to trap, without heating, a single metallic nanoparticle of 150 nm that acts as a highly sensitive probe for external radiation pressure. An Allan-deviation-based stability analysis of the setup yields an optimal 0.1-Hz measurement bandwidth over which the microscope is thermally limited. Over this bandwidth, and with a genuine sine-wave external drive, we demonstrate an optical force resolution down to 3 fN in water at room temperature with a dynamical range for force detection that covers almost 2 orders of magnitude. This resolution is reached in both the confined regime and the freely diffusing regime of the optical trap. In the latter, we measure induced displacements of 10−11 m on the trapped nanoparticle spatially confined within less than 25 nm along the optical axis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We propose and evaluate a new type of optical force microscope based on a standing-wave optical trap. Our microscope, calibrated in situ and operating in a dynamic mode, is able to trap, without heating, a single metallic nanoparticle of 150 nm that acts as a highly sensitive probe for external radiation pressure. An Allan-deviation-based stability analysis of the setup yields an optimal 0.1-Hz measurement bandwidth over which the microscope is thermally limited. Over this bandwidth, and with a genuine sine-wave external drive, we demonstrate an optical force resolution down to 3 fN in water at room temperature with a dynamical range for force detection that covers almost 2 orders of magnitude. This resolution is reached in both the confined regime and the freely diffusing regime of the optical trap. In the latter, we measure induced displacements of 10−11 m on the trapped nanoparticle spatially confined within less than 25 nm along the optical axis. |
K, Muchowska; E, Chevallot-Beroux; J, Moran Recreating ancient metabolic pathways before enzymes. Article de journal Dans: Bioorganic & Medicinal Chemistry, 2019. @article{K2019, title = {Recreating ancient metabolic pathways before enzymes.}, author = {Muchowska K and Chevallot-Beroux E and Moran J}, editor = {Copyright © 2019. Published by Elsevier Ltd}, url = {https://www.sciencedirect.com/science/article/pii/S0968089619300033?via%3Dihub}, doi = {10.1016/j.bmc.2019.03.012}, year = {2019}, date = {2019-03-07}, journal = {Bioorganic & Medicinal Chemistry}, abstract = {The biochemistry of all living organisms uses complex, enzyme-catalyzed metabolic reaction networks. Yet, at life's origins, enzymes had not yet evolved. Therefore, it has been postulated that non-enzymatic metabolic pathways predated their enzymatic counterparts. In this account article, we describe our recent work to evaluate whether two ancient carbon fixation pathways, the rTCA (reductive tricarboxylic acid) cycle and the reductive AcCoA (Wood-Ljungdahl) pathway, could have operated without enzymes and therefore have originated as prebiotic chemistry. We also describe the discovery of an Fe2+-promoted complex reaction network that may represent a prebiotic predecessor to the TCA and glyoxylate cycles. The collective results support the idea that most central metabolic pathways could have roots in prebiotic chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The biochemistry of all living organisms uses complex, enzyme-catalyzed metabolic reaction networks. Yet, at life's origins, enzymes had not yet evolved. Therefore, it has been postulated that non-enzymatic metabolic pathways predated their enzymatic counterparts. In this account article, we describe our recent work to evaluate whether two ancient carbon fixation pathways, the rTCA (reductive tricarboxylic acid) cycle and the reductive AcCoA (Wood-Ljungdahl) pathway, could have operated without enzymes and therefore have originated as prebiotic chemistry. We also describe the discovery of an Fe2+-promoted complex reaction network that may represent a prebiotic predecessor to the TCA and glyoxylate cycles. The collective results support the idea that most central metabolic pathways could have roots in prebiotic chemistry. |
Krystek, M; Pakulski, D; Patroniak, V; Górski, M; Szojda, L; Ciesielski, A; Samorì, P High‐Performance Graphene‐Based Cementitious Composites Article de journal Dans: ADVANCED SCIENCE, 6 (1801195), 2019. @article{Krystek2019, title = {High‐Performance Graphene‐Based Cementitious Composites}, author = {M. Krystek and D. Pakulski and V. Patroniak and M. Górski and L. Szojda and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library }, url = { https://doi.org/10.1002/advs.201801195}, doi = {10.1002/advs.201801195}, year = {2019}, date = {2019-03-07}, journal = {ADVANCED SCIENCE}, volume = {6}, number = {1801195}, abstract = {This study reports on the development of a cementitious composite incorporating electrochemically exfoliated graphene (EEG). This hybrid functional material features significantly enhanced microstructure and mechanical properties, as well as unaffected workability; thus, it outperforms previously reported cementitious composites containing graphene derivatives. The manufacturing of the composite relies on a simple and efficient method that enables the uniform dispersion of EEG within cement matrix in the absence of surfactants. Different from graphene oxide, EEG is found to not agglomerate in cement alkaline environment, thereby not affecting the fluidity of cementitious composites. The addition of 0.05 wt% graphene content to ordinary Portland cement results in an increase up to 79%, 8%, and 9% for the tensile strength, compressive strength, and Young's modulus, respectively. Remarkably, it is found that the addition of EEG promotes the hydration reaction of both alite and belite, thus leading to the formation of a large fraction of 3CaO·2SiO2·3H2O (C‐S‐H) phase. These findings represent a major step forward toward the practical application of nanomaterials in civil engineering.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study reports on the development of a cementitious composite incorporating electrochemically exfoliated graphene (EEG). This hybrid functional material features significantly enhanced microstructure and mechanical properties, as well as unaffected workability; thus, it outperforms previously reported cementitious composites containing graphene derivatives. The manufacturing of the composite relies on a simple and efficient method that enables the uniform dispersion of EEG within cement matrix in the absence of surfactants. Different from graphene oxide, EEG is found to not agglomerate in cement alkaline environment, thereby not affecting the fluidity of cementitious composites. The addition of 0.05 wt% graphene content to ordinary Portland cement results in an increase up to 79%, 8%, and 9% for the tensile strength, compressive strength, and Young's modulus, respectively. Remarkably, it is found that the addition of EEG promotes the hydration reaction of both alite and belite, thus leading to the formation of a large fraction of 3CaO·2SiO2·3H2O (C‐S‐H) phase. These findings represent a major step forward toward the practical application of nanomaterials in civil engineering. |
Hou, Lili; Zhang, Xiaoyan; Cotella, Giovanni F; Carnicella, Giuseppe; Herder, Martin; Schmidt, Bernd M; Pätzel, Michael; andFranco Cacialli, Stefan Hecht; Samorì, Paolo Optically switchable organic light-emitting transistors Article de journal Dans: Nature Nanotechnology, 14 , p. 347-353, 2019. @article{Hou2019b, title = {Optically switchable organic light-emitting transistors}, author = {Lili Hou and Xiaoyan Zhang and Giovanni F Cotella and Giuseppe Carnicella and Martin Herder and Bernd M Schmidt and Michael Pätzel and Stefan Hecht andFranco Cacialli and Paolo Samorì }, editor = {Nature}, url = {https://www.nature.com/articles/s41565-019-0370-9}, doi = {10.1038/s41565-019-0370-9}, year = {2019}, date = {2019-02-18}, journal = {Nature Nanotechnology}, volume = {14}, pages = {347-353}, abstract = {Organic light-emitting transistors are pivotal components for emerging opto- and nanoelectronics applications, such as logic circuitries and smart displays. Within this technology sector, the integration of multiple functionalities in a single electronic device remains the key challenge. Here we show optically switchable organic light-emitting transistors fabricated through a judicious combination of light-emitting semiconductors and photochromic molecules. Irradiation of the solution-processed films at selected wavelengths enables the efficient and reversible tuning of charge transport and electroluminescence simultaneously, with a high degree of modulation (on/off ratios up to 500) in the three primary colours. Different emitting patterns can be written and erased through a non-invasive and mask-free process, on a length scale of a few micrometres in a single device, thereby rendering this technology potentially promising for optically gated highly integrated full-colour displays and active optical memory.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organic light-emitting transistors are pivotal components for emerging opto- and nanoelectronics applications, such as logic circuitries and smart displays. Within this technology sector, the integration of multiple functionalities in a single electronic device remains the key challenge. Here we show optically switchable organic light-emitting transistors fabricated through a judicious combination of light-emitting semiconductors and photochromic molecules. Irradiation of the solution-processed films at selected wavelengths enables the efficient and reversible tuning of charge transport and electroluminescence simultaneously, with a high degree of modulation (on/off ratios up to 500) in the three primary colours. Different emitting patterns can be written and erased through a non-invasive and mask-free process, on a length scale of a few micrometres in a single device, thereby rendering this technology potentially promising for optically gated highly integrated full-colour displays and active optical memory. |
Chevallot-Beroux, Elodie; Ako, Ayuk M; Schmitt, Wolfgang; Twamley, Brendan; Moran, Joseph; Corinne, Boudon; Ruhlmannc, Laurent; Mameri, Samir Synthesis of new Mn19 analogues and their structural, electrochemical and catalytic properties Article de journal Dans: Dalton Transactions, (15), 2019. @article{Chevallot-Beroux2019, title = {Synthesis of new Mn19 analogues and their structural, electrochemical and catalytic properties }, author = { Elodie Chevallot-Beroux and Ayuk M. Ako and Wolfgang Schmitt and Brendan Twamley and Joseph Moran and Boudon Corinne and Laurent Ruhlmannc and Samir Mameri}, editor = {Royal Society of Chemistry}, doi = {10.1039/C8DT04807J}, year = {2019}, date = {2019-02-13}, journal = {Dalton Transactions}, number = {15}, abstract = {We report the synthesis and structural characterisation of new Mn19 and Mn18M analogues, [MnIII12MnII7(μ4-O)8(μ3-OCH3)2(μ3-Br)6(HLMe)12(MeOH)6]Br2 (2) and [MnIII12MnII6Sr(μ4-O8(μ3-Cl)8(HLMe)12(MeCN)6]Cl2 cluster (3), where H3LMe is 2,6-bis(hydroxymethyl)-p-cresol. The electrochemistry of 2 and 3 has been investigated and their activity as catalysts in the oxidation of benzyl alcohol has been evaluated. Selective oxidation of benzyl alcohol to benzaldehyde by O2 was achieved using 1 mol% of catalyst with conversions of 74% (2) and 60% (3) at 140 °C using TEMPO as a co-catalyst. No partial conversion of benzaldehyde to benzoic acid was observed. The results obtained revealed that different operative parameters – such as catalyst loading, temperature, time, solvent and the presence of molecular oxygen – played an important role in the selective oxidation of benzyl alcohol.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report the synthesis and structural characterisation of new Mn19 and Mn18M analogues, [MnIII12MnII7(μ4-O)8(μ3-OCH3)2(μ3-Br)6(HLMe)12(MeOH)6]Br2 (2) and [MnIII12MnII6Sr(μ4-O8(μ3-Cl)8(HLMe)12(MeCN)6]Cl2 cluster (3), where H3LMe is 2,6-bis(hydroxymethyl)-p-cresol. The electrochemistry of 2 and 3 has been investigated and their activity as catalysts in the oxidation of benzyl alcohol has been evaluated. Selective oxidation of benzyl alcohol to benzaldehyde by O2 was achieved using 1 mol% of catalyst with conversions of 74% (2) and 60% (3) at 140 °C using TEMPO as a co-catalyst. No partial conversion of benzaldehyde to benzoic acid was observed. The results obtained revealed that different operative parameters – such as catalyst loading, temperature, time, solvent and the presence of molecular oxygen – played an important role in the selective oxidation of benzyl alcohol. |
Thomas, A; Lethuillier-Karl, L; K. Nagarajan, Vergauwe R M A; George, J; Chervy, T; Shalabney, A; Devaux, E; Genet, C; nd Ebbesen, Morana J T W Tilting a ground-state reactivity landscape by vibrational strong coupling Article de journal Dans: Science, 363 (6427), p. 615-619, 2019. @article{Thomas2019, title = {Tilting a ground-state reactivity landscape by vibrational strong coupling}, author = {A. Thomas and L. Lethuillier-Karl and K. Nagarajan, R. M. A. Vergauwe and J. George and T. Chervy and A. Shalabney and E. Devaux and C. Genet and J. Morana nd T. W. Ebbesen}, url = {https://science.sciencemag.org/content/363/6427/615.abstract}, doi = {10.1126/science.aau7742 }, year = {2019}, date = {2019-02-08}, journal = {Science}, volume = {363}, number = {6427}, pages = {615-619}, abstract = {Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites—Si–C and Si–O, respectively—as a function of VSC of three distinct vibrational modes in the dark. The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other. Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites—Si–C and Si–O, respectively—as a function of VSC of three distinct vibrational modes in the dark. The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other. Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling. |
Li, S L; Zhang, L; Zhong, X; Gobbi, M; Bertolazzi, S; Guo, W; Wu, B; Liu, Y; Xu, N; Niu, W; Hao, Y; Orgiu, E; Samori, P Nano-Subsidence-Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays Article de journal Dans: ACS Nano, 13 (2), p. 2654–2662, 2019. @article{Li2019, title = {Nano-Subsidence-Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays}, author = {S.L. Li and L. Zhang and X. Zhong and M. Gobbi and S. Bertolazzi and W. Guo and B. Wu and Y. Liu and N. Xu and W. Niu and Y. Hao and E. Orgiu and P. Samori}, editor = {ASC Publications}, url = {https://pubs.acs.org/doi/10.1021/acsnano.9b00889}, doi = {10.1021/acsnano.9b00889}, year = {2019}, date = {2019-02-07}, journal = {ACS Nano}, volume = {13}, number = {2}, pages = {2654–2662}, abstract = {The spatially precise integration of arrays of micropatterned two-dimensional (2D) crystals onto three-dimensionally structured Si/SiO2 substrates represents an attractive, low-cost system-on-chip strategy toward the realization of extended functions in silicon microelectronics. However, the reliable integration of such atomically thin arrays on planar patterned surfaces has proven challenging due to their poor adhesion to underlying substrates, as ruled by weak van der Waals interactions. Here, we report on an integration method utilizing the flexibility of the atomically thin crystals and their physical subsidence in liquids, which enables the reliable fabrication of the micropatterned 2D materials/Si arrays. Our photodiode devices display peak sensitivity as high as 0.35 A/W and external quantum efficiency (EQE) of ∼90%. The nano-subsidence technique represents a viable path to on-chip integration of 2D crystals onto silicon for advanced microelectronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The spatially precise integration of arrays of micropatterned two-dimensional (2D) crystals onto three-dimensionally structured Si/SiO2 substrates represents an attractive, low-cost system-on-chip strategy toward the realization of extended functions in silicon microelectronics. However, the reliable integration of such atomically thin arrays on planar patterned surfaces has proven challenging due to their poor adhesion to underlying substrates, as ruled by weak van der Waals interactions. Here, we report on an integration method utilizing the flexibility of the atomically thin crystals and their physical subsidence in liquids, which enables the reliable fabrication of the micropatterned 2D materials/Si arrays. Our photodiode devices display peak sensitivity as high as 0.35 A/W and external quantum efficiency (EQE) of ∼90%. The nano-subsidence technique represents a viable path to on-chip integration of 2D crystals onto silicon for advanced microelectronics. |
D. Pakulski A. Gorczyński, Czepa Liu Ortolani Morandi Patroniak Ciesielski Samorì W Z L V V A P Novel Keplerate type polyoxometalate-surfactant-graphene hybrids as advanced electrode materials for supercapacitors Article de journal Dans: Energy Storage Materials, 17 (February 2019), p. p 186-193, 2019. @article{Pakulski2018, title = {Novel Keplerate type polyoxometalate-surfactant-graphene hybrids as advanced electrode materials for supercapacitors}, author = {D. Pakulski, A. Gorczyński, W. Czepa, Z. Liu, L. Ortolani, V. Morandi, V. Patroniak, A. Ciesielski, P. Samorì}, editor = {ELSEVIER}, url = {https://doi.org/10.1016/j.ensm.2018.11.012}, year = {2019}, date = {2019-02-01}, journal = {Energy Storage Materials}, volume = {17}, number = {February 2019}, pages = {p 186-193}, abstract = {The development of novel materials for enhanced electrochemical energy storage applications, in particular for the fabrication of supercapacitors (SCs) displaying increased properties, is a milestone of both fundamental and technological relevance. Among nanostructured materials, polyoxometalates (POMs) combined with various carbon-based nanostructures represent a very promising class of hybrid systems for energy storage, yet, guidelines for their rational design and synthesis leading to high-performance SCs is still lacking. Here, we have produced a novel hybrid architecture based on Keplerate type POM (Mo132) functionalized with dodecyltrimethylammonium bromide (DTAB), which upon mixing with electrochemically exfoliated graphene (EEG) nanosheets results in the formation of porous 3D superstructures. Mo132-DTAB-EEG combines the redox activity of POMs and high electrical conductivity of graphene, all synergically mediated by the surfactant-assisted porosity enhancement, to form new electrode materials for SCs. Cyclic voltammetry and galvanostatic charge/discharge electrochemical studies on Mo132-DTAB-EEG performed in aqueous H2SO4 electrolyte revealed that the unique combination of these three components yields highly efficient energy storage materials. In particular, our highly porous hybrids system exhibits high specific capacitance of 65 F g−1 (93 F cm−3, 93mFcm−2) combined with excellent stability (99% of specific capacitance retained) after 5000 charge/discharge cycles at different current densities, overall displaying significantly improved performance compared to pristine electrochemically exfoliated graphene material. Strong non-covalent interactions between Keplerate type polyoxometalate Mo132-DTAB and graphene surface offer higher stability compared to other hybrid POM/carbon-based systems, and unique electrical properties of the multicomponent structure, thereby paving the way towards the development of novel, and potentially multifunctional, POM-based architectures to be exploited as SC electrode materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of novel materials for enhanced electrochemical energy storage applications, in particular for the fabrication of supercapacitors (SCs) displaying increased properties, is a milestone of both fundamental and technological relevance. Among nanostructured materials, polyoxometalates (POMs) combined with various carbon-based nanostructures represent a very promising class of hybrid systems for energy storage, yet, guidelines for their rational design and synthesis leading to high-performance SCs is still lacking. Here, we have produced a novel hybrid architecture based on Keplerate type POM (Mo132) functionalized with dodecyltrimethylammonium bromide (DTAB), which upon mixing with electrochemically exfoliated graphene (EEG) nanosheets results in the formation of porous 3D superstructures. Mo132-DTAB-EEG combines the redox activity of POMs and high electrical conductivity of graphene, all synergically mediated by the surfactant-assisted porosity enhancement, to form new electrode materials for SCs. Cyclic voltammetry and galvanostatic charge/discharge electrochemical studies on Mo132-DTAB-EEG performed in aqueous H2SO4 electrolyte revealed that the unique combination of these three components yields highly efficient energy storage materials. In particular, our highly porous hybrids system exhibits high specific capacitance of 65 F g−1 (93 F cm−3, 93mFcm−2) combined with excellent stability (99% of specific capacitance retained) after 5000 charge/discharge cycles at different current densities, overall displaying significantly improved performance compared to pristine electrochemically exfoliated graphene material. Strong non-covalent interactions between Keplerate type polyoxometalate Mo132-DTAB and graphene surface offer higher stability compared to other hybrid POM/carbon-based systems, and unique electrical properties of the multicomponent structure, thereby paving the way towards the development of novel, and potentially multifunctional, POM-based architectures to be exploited as SC electrode materials. |
Lichosyt, D; Zhang, Y; Hurej, K; Dydio, P Catalytic Transition Metal Systems for Functionalization of Unreactive Sites of Molecules Article de journal Dans: Nature Catalysis, 2 , p. 114-122, 2019. @article{Lichosyt2019, title = {Catalytic Transition Metal Systems for Functionalization of Unreactive Sites of Molecules}, author = {Lichosyt, D. and Zhang, Y. and Hurej, K. and Dydio, P.}, editor = {Nature}, url = {https://www.nature.com/articles/s41929-018-0207-1}, year = {2019}, date = {2019-01-29}, journal = {Nature Catalysis}, volume = {2}, pages = {114-122}, abstract = {Catalytic reactions occur readily at the sites of starting materials that are both innately reactive and sterically accessible, or that are predisposed by a functional group amenable to direct a catalyst. However, selective reactions at unbiased sites of substrates remain challenging and typically require additional preactivation steps or the use of highly reactive reagents. Here we report dual-catalytic transition metal systems that merge a reversible activation cycle with a functionalization cycle, which together enable the functionalization of substrates at their inherently unreactive sites. By engaging the Ru- or Fe-catalysed equilibrium between an alcohol and an aldehyde, methods for Pd-catalysed β-arylation of aliphatic alcohols and Rh-catalysed γ-hydroarylation of allylic alcohols were developed. The mild conditions, functional group tolerance and broad scope (81 examples) demonstrate the synthetic applicability of the dual-catalytic systems. This work highlights the potential of the multicatalytic approach to address challenging transformations to circumvent multistep procedures and the use of highly reactive reagents in organic synthesis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Catalytic reactions occur readily at the sites of starting materials that are both innately reactive and sterically accessible, or that are predisposed by a functional group amenable to direct a catalyst. However, selective reactions at unbiased sites of substrates remain challenging and typically require additional preactivation steps or the use of highly reactive reagents. Here we report dual-catalytic transition metal systems that merge a reversible activation cycle with a functionalization cycle, which together enable the functionalization of substrates at their inherently unreactive sites. By engaging the Ru- or Fe-catalysed equilibrium between an alcohol and an aldehyde, methods for Pd-catalysed β-arylation of aliphatic alcohols and Rh-catalysed γ-hydroarylation of allylic alcohols were developed. The mild conditions, functional group tolerance and broad scope (81 examples) demonstrate the synthetic applicability of the dual-catalytic systems. This work highlights the potential of the multicatalytic approach to address challenging transformations to circumvent multistep procedures and the use of highly reactive reagents in organic synthesis. |
Ye Wang Amine Slassi, Marc-Antoine Stoeckel Simone Bertolazzi Jerôme Cornil David Beljonne Paolo Samorì Doping of Monolayer Transition-Metal Dichalcogenides via Physisorption of Aromatic Solvent Molecules Article de journal Dans: J. Phys. Chem. Lett, 10 (3), p. 540-547, 2019. @article{Wang2019, title = {Doping of Monolayer Transition-Metal Dichalcogenides via Physisorption of Aromatic Solvent Molecules}, author = {Ye Wang, Amine Slassi, Marc-Antoine Stoeckel, Simone Bertolazzi, Jerôme Cornil, David Beljonne , Paolo Samorì}, editor = {Copyright © 2019 American Chemical Society }, url = {https://pubs.acs.org/doi/10.1021/acs.jpclett.8b03697}, doi = {10.1021/acs.jpclett.8b03697}, year = {2019}, date = {2019-01-16}, journal = {J. Phys. Chem. Lett}, volume = {10}, number = {3}, pages = {540-547}, abstract = {Two-dimensional (2D) transition-metal dichalcogenides (TMDs) recently emerged as novel materials displaying a wide variety of physicochemical properties that render them unique scaffolds for high-performance (opto)electronics. The controlled physisorption of molecules on the TMD surface is a viable approach for tuning their optical and electronic properties. Solvents, made of small aromatic molecules, are frequently employed for the cleaning of the 2D materials or as a “dispersant” for their chemical functionalization with larger (macro)molecules, without considering their potential key effect in locally modifying the characteristics of 2D materials. In this work, we demonstrate how the electronic and optical properties of a mechanically exfoliated monolayer of MoS2 and WSe2 are modified when physically interacting with small aromatic molecules of common solvents. Low-temperature photoluminescence (PL) spectra recorded at 78 K revealed that physisorbed benzene derivatives could modulate the charge carrier density in monolayer TMDs, hence affecting the switching between a neutral exciton and trion (charged exciton). By combining experimental evidence with density functional theory calculations, we confirm that charge-transfer doping on TMDs depends not only on the difference in chemical potential between molecules and 2D materials but also on the thermodynamic stability of physisorption. Our results provide unambiguous evidences of the great potential of optical and electrical tuning of monolayer MoS2 and WSe2 by physisorption of small aromatic solvent molecules, which is highly relevant for both fundamental studies and device application purposes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two-dimensional (2D) transition-metal dichalcogenides (TMDs) recently emerged as novel materials displaying a wide variety of physicochemical properties that render them unique scaffolds for high-performance (opto)electronics. The controlled physisorption of molecules on the TMD surface is a viable approach for tuning their optical and electronic properties. Solvents, made of small aromatic molecules, are frequently employed for the cleaning of the 2D materials or as a “dispersant” for their chemical functionalization with larger (macro)molecules, without considering their potential key effect in locally modifying the characteristics of 2D materials. In this work, we demonstrate how the electronic and optical properties of a mechanically exfoliated monolayer of MoS2 and WSe2 are modified when physically interacting with small aromatic molecules of common solvents. Low-temperature photoluminescence (PL) spectra recorded at 78 K revealed that physisorbed benzene derivatives could modulate the charge carrier density in monolayer TMDs, hence affecting the switching between a neutral exciton and trion (charged exciton). By combining experimental evidence with density functional theory calculations, we confirm that charge-transfer doping on TMDs depends not only on the difference in chemical potential between molecules and 2D materials but also on the thermodynamic stability of physisorption. Our results provide unambiguous evidences of the great potential of optical and electrical tuning of monolayer MoS2 and WSe2 by physisorption of small aromatic solvent molecules, which is highly relevant for both fundamental studies and device application purposes. |
Witomska Samanta Liu Zhaoyang, Czepa Wlodzimierz Aliprandi Alessandro Pakulski Dawid Pawluc Piotr Ciesielski Artur Samori Paolo Graphene Oxide Hybrid with Sulfur–Nitrogen Polymer for High-Performance Pseudocapacitors Article de journal Dans: J. Am. Chem. Soc., 141 (1), p. 482-487, 2019. @article{, title = {Graphene Oxide Hybrid with Sulfur–Nitrogen Polymer for High-Performance Pseudocapacitors}, author = {Witomska Samanta , Liu Zhaoyang , Czepa, Wlodzimierz , Aliprandi, Alessandro , Pakulski, Dawid , Pawluc, Piotr , Ciesielski, Artur , Samori Paolo ,}, editor = {Copyright © 2019 American Chemical Society}, url = {https://pubs.acs.org/doi/10.1021/jacs.8b11181}, doi = {10.1021/jacs.8b11181}, year = {2019}, date = {2019-01-09}, journal = {J. Am. Chem. Soc.}, volume = {141}, number = {1}, pages = {482-487}, abstract = {Toward the introduction of fast faradaic pseudocapacitive behavior and the increase of the specific capacitance of carbon-based electrodes, we covalently functionalized graphene oxide with a redox active thiourea-formaldehyde polymer, yielding a multifunctional hybrid system. The multiscale physical and chemical characterization of the novel 3-dimensional hybrid revealed high material porosity with high specific surface area (402 m2 g–1) and homogeneous element distribution. The presence of multiple functional groups comprising sulfur, nitrogen, and oxygen provide additional contribution of Faradaic redox reaction in supercapacity performance, leading to a high effective electrochemical pseudocapacitance. Significantly, our graphene-based 3-dimensional thiourea-formaldehyde hybrid exhibited specific capacitance as high as 400 F g–1, areal capacitance of 160 mF cm–2, and an energy density of 11.1 mWh cm–3 at scan rate of 1 mV s–1 with great capacitance retention (100%) after 5000 cycles at scan rate of 100 mV s–}, keywords = {}, pubstate = {published}, tppubtype = {article} } Toward the introduction of fast faradaic pseudocapacitive behavior and the increase of the specific capacitance of carbon-based electrodes, we covalently functionalized graphene oxide with a redox active thiourea-formaldehyde polymer, yielding a multifunctional hybrid system. The multiscale physical and chemical characterization of the novel 3-dimensional hybrid revealed high material porosity with high specific surface area (402 m2 g–1) and homogeneous element distribution. The presence of multiple functional groups comprising sulfur, nitrogen, and oxygen provide additional contribution of Faradaic redox reaction in supercapacity performance, leading to a high effective electrochemical pseudocapacitance. Significantly, our graphene-based 3-dimensional thiourea-formaldehyde hybrid exhibited specific capacitance as high as 400 F g–1, areal capacitance of 160 mF cm–2, and an energy density of 11.1 mWh cm–3 at scan rate of 1 mV s–1 with great capacitance retention (100%) after 5000 cycles at scan rate of 100 mV s– |
Chang-Bo Huang; Samanta, Witomska; Alessandro Aliprandi; Marc-Antoine Stoeckel; Massimo Bonini; Artur Ciesielski* & Paolo Samorì* Molecule–Graphene Hybrid Materials with Tunable Mechanoresponse: Highly Sensitive Pressure Sensors for Health Monitoring Article de journal Dans: Advanced Materials, 31(1), 1804600, 2019. @article{Huang2018, title = {Molecule–Graphene Hybrid Materials with Tunable Mechanoresponse: Highly Sensitive Pressure Sensors for Health Monitoring}, author = {Chang-Bo Huang; Samanta, Witomska; Alessandro Aliprandi; Marc-Antoine Stoeckel; Massimo Bonini; Artur Ciesielski* & Paolo Samorì*}, editor = {Wiley Online Library }, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201804600}, doi = {10.1002/adma.201804600}, year = {2019}, date = {2019-01-04}, journal = {Advanced Materials, 31(1), 1804600}, abstract = {The development of pressure sensors is crucial for the implementation of electronic skins and for health monitoring integrated into novel wearable devices. Tremendous effort is devoted toward improving their sensitivity, e.g., by employing microstructured electrodes or active materials through cumbersome processes. Here, a radically new type of piezoresistive pressure sensor based on a millefeuille‐like architecture of reduced graphene oxide (rGO) intercalated by covalently tethered molecular pillars holding on‐demand mechanical properties are fabricated. By applying a tiny pressure to the multilayer structure, the electron tunnelling ruling the charge transport between successive rGO sheets yields a colossal decrease in the material's electrical resistance. Significantly, the intrinsic rigidity of the molecular pillars employed enables the fine‐tuning of the sensor's sensitivity, reaching sensitivities as high as 0.82 kPa−1 in the low pressure region (0–0.6 kPa), with short response times (≈24 ms) and detection limit (7 Pa). The pressure sensors enable efficient heartbeat monitoring and can be easily transformed into a matrix capable of providing a 3D map of the pressure exerted by different objects. }, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of pressure sensors is crucial for the implementation of electronic skins and for health monitoring integrated into novel wearable devices. Tremendous effort is devoted toward improving their sensitivity, e.g., by employing microstructured electrodes or active materials through cumbersome processes. Here, a radically new type of piezoresistive pressure sensor based on a millefeuille‐like architecture of reduced graphene oxide (rGO) intercalated by covalently tethered molecular pillars holding on‐demand mechanical properties are fabricated. By applying a tiny pressure to the multilayer structure, the electron tunnelling ruling the charge transport between successive rGO sheets yields a colossal decrease in the material's electrical resistance. Significantly, the intrinsic rigidity of the molecular pillars employed enables the fine‐tuning of the sensor's sensitivity, reaching sensitivities as high as 0.82 kPa−1 in the low pressure region (0–0.6 kPa), with short response times (≈24 ms) and detection limit (7 Pa). The pressure sensors enable efficient heartbeat monitoring and can be easily transformed into a matrix capable of providing a 3D map of the pressure exerted by different objects. |
Rizzi, Vito ; Prasetyanto, Eko Adi ; Chen, Pengkun ; Gubitosa, Jennifer ; Fini, Paola ; Agostiano, Angela ; De Cola, Luisa ; Cosma, Pinalysa "Amino grafted MCM-41 as highly efficient and reversible ecofriendly adsorbent material for the Direct Blue removal from wastewater" Article de journal Dans: JOURNAL OF MOLECULAR LIQUIDS, 273 , p. 435-446 , 2019. @article{Rizzi2019, title = {"Amino grafted MCM-41 as highly efficient and reversible ecofriendly adsorbent material for the Direct Blue removal from wastewater"}, author = {Rizzi, Vito and Prasetyanto, Eko Adi and Chen, Pengkun and Gubitosa, Jennifer and Fini, Paola and Agostiano, Angela and De Cola, Luisa and Cosma, Pinalysa}, editor = {JOURNAL OF MOLECULAR LIQUIDS}, doi = {10.1016/j.molliq.2018.10.060}, year = {2019}, date = {2019-01-01}, journal = {JOURNAL OF MOLECULAR LIQUIDS}, volume = { 273}, pages = {435-446 }, abstract = {The very high adsorption efficiency of Direct Blue (DB), an anionic toxic azo dye, onto amino grafted mesoporous silica nanoparticles (MCM-41), was studied in this paper, for possible industrial applications. Interesting challenges and advances are proposed in this field, presenting an adsorbent able to efficiently and rapidly remove the anionic dye from water. The important added value of this work regards the system recycle, which allows both the DB and adsorbent material recover, with a global reduction of the environmental impact, in the viewpoint of the green economy. Indeed, this paper is the first example of very fast removal and recycle of great amounts of DB with adsorbent materials characterized by impressive adsorption/desorption capacities, at least of around 300 mg/g for each adsorption cycle, potentially increasable by performing consecutive cycles of DB adsorption/desorption. In detail, the MCM-41 amino functionalization (MCM-41-NH2) was obtained after (MCM-41-POST) and during (MCM-41-PRE) the synthesis of MCM-41, obtaining materials with different behavior towards the DB adsorption. The MCM-41-NH2 surface features and porous structure, before and after the dye adsorption, were carefully characterized. Considering the adsorption process, for investigating the nature of the DB/MCM-41-NH2 interaction, several parameters were studied: the contact time, the DB solutions pH values, adsorbent material and dye amount, with the additional analysis of how the adsorption process was influenced by the presence of electrolytes. The isotherms of adsorption were also considered. Although MCM-41-PRE exhibited a higher affinity towards DB molecules, the MCM-41-POST were able to rapidly desorb it, thus recycling both DB and the adsorbent material. (C) 2018 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The very high adsorption efficiency of Direct Blue (DB), an anionic toxic azo dye, onto amino grafted mesoporous silica nanoparticles (MCM-41), was studied in this paper, for possible industrial applications. Interesting challenges and advances are proposed in this field, presenting an adsorbent able to efficiently and rapidly remove the anionic dye from water. The important added value of this work regards the system recycle, which allows both the DB and adsorbent material recover, with a global reduction of the environmental impact, in the viewpoint of the green economy. Indeed, this paper is the first example of very fast removal and recycle of great amounts of DB with adsorbent materials characterized by impressive adsorption/desorption capacities, at least of around 300 mg/g for each adsorption cycle, potentially increasable by performing consecutive cycles of DB adsorption/desorption. In detail, the MCM-41 amino functionalization (MCM-41-NH2) was obtained after (MCM-41-POST) and during (MCM-41-PRE) the synthesis of MCM-41, obtaining materials with different behavior towards the DB adsorption. The MCM-41-NH2 surface features and porous structure, before and after the dye adsorption, were carefully characterized. Considering the adsorption process, for investigating the nature of the DB/MCM-41-NH2 interaction, several parameters were studied: the contact time, the DB solutions pH values, adsorbent material and dye amount, with the additional analysis of how the adsorption process was influenced by the presence of electrolytes. The isotherms of adsorption were also considered. Although MCM-41-PRE exhibited a higher affinity towards DB molecules, the MCM-41-POST were able to rapidly desorb it, thus recycling both DB and the adsorbent material. (C) 2018 Elsevier B.V. All rights reserved. |
Travaglini, Leana ; Picchetti, Pierre ; Totovao, Ricardo ; Prasetyanto, Eko Adi ; De Cola, Luisa "Highly degradable imine-doped mesoporous silica particles" Article de journal Dans: MATERIALS CHEMISTRY FRONTIERS, 3 (1), p. 111-119 , 2019. @article{Travaglini2019b, title = {"Highly degradable imine-doped mesoporous silica particles"}, author = {Travaglini, Leana and Picchetti, Pierre and Totovao, Ricardo and Prasetyanto, Eko Adi and De Cola, Luisa}, editor = {MATERIALS CHEMISTRY FRONTIERS}, doi = {10.1039/c8qm00438b}, year = {2019}, date = {2019-01-01}, journal = {MATERIALS CHEMISTRY FRONTIERS}, volume = {3}, number = {1}, pages = {111-119 }, abstract = {The degradation of mesoporous silica particles (MSPs) in water is a key aspect that boosts their use especially in bio-related fields. Although MSP degradation in aqueous media has been proven, big efforts have been devoted to tuning silica dissolution in order to obtain functional materials whose degradation can be finely controlled and enhanced, to tackle the issue of bioaccumulation. In particular, the introduction of stimuli-responsive functional groups into the silica framework was proven to be a successful strategy. Yet, the fast dissolution of silica particles in aqueous media in the absence of external stimuli has to be fully addressed. In this context, we reported herein the preparation and thorough characterisation of MSPs containing imine groups embedded within the silica framework (Im-MSPs). Particles with different contents of imine groups have been investigated in order to assess the effect on the physicochemical properties and the Im-MSPs showed fast degradation in both acidic and neutral aqueous solutions, at a rate that depended on the pH value. Of special interest is their fast degradation at acidic pH, where instead MSPs are normally more stable. The described results unveil the potential of these particles in applications that require a fast degradation in aqueous media.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The degradation of mesoporous silica particles (MSPs) in water is a key aspect that boosts their use especially in bio-related fields. Although MSP degradation in aqueous media has been proven, big efforts have been devoted to tuning silica dissolution in order to obtain functional materials whose degradation can be finely controlled and enhanced, to tackle the issue of bioaccumulation. In particular, the introduction of stimuli-responsive functional groups into the silica framework was proven to be a successful strategy. Yet, the fast dissolution of silica particles in aqueous media in the absence of external stimuli has to be fully addressed. In this context, we reported herein the preparation and thorough characterisation of MSPs containing imine groups embedded within the silica framework (Im-MSPs). Particles with different contents of imine groups have been investigated in order to assess the effect on the physicochemical properties and the Im-MSPs showed fast degradation in both acidic and neutral aqueous solutions, at a rate that depended on the pH value. Of special interest is their fast degradation at acidic pH, where instead MSPs are normally more stable. The described results unveil the potential of these particles in applications that require a fast degradation in aqueous media. |
2018 |
Agostino Galanti; Valentin, Diez-Cabanes; Jasmin Santoro; Michal Valášek; Andrea Minoia; Marcel Mayor; Jérôme Cornil; Paolo Samorì; Electronic Decoupling in C3-Symmetrical Light-Responsive Tris(Azobenzene) Scaffolds: Self-Assembly and Multiphotochromism Article de journal Dans: J. Am. Chem. Soc., 2018, 140 (47), 16062–16070, 2018. @article{Galanti2018, title = {Electronic Decoupling in C3-Symmetrical Light-Responsive Tris(Azobenzene) Scaffolds: Self-Assembly and Multiphotochromism}, author = {Agostino, Galanti; Valentin, Diez-Cabanes; Jasmin, Santoro; Michal, Valášek; Andrea, Minoia; Marcel, Mayor; Jérôme, Cornil; Paolo, Samorì;}, editor = {ACS Publcation}, url = {https://pubs.acs.org/doi/10.1021/jacs.8b06324}, doi = {10.1021/jacs.8b06324}, year = {2018}, date = {2018-10-31}, journal = {J. Am. Chem. Soc., 2018, 140 (47), 16062–16070}, abstract = {We report the synthesis of a novel C3-symmetrical multiphotochromic molecule bearing three azobenzene units at positions 1, 3, 5 of the central phenyl ring. The unique geometrical design of such a rigid scaffold enables the electronic decoupling of the azobenzene moieties to guarantee their simultaneous isomerization. Photoswitching of all azobenzenes in solution was demonstrated by means of UV–vis absorption spectroscopy and high performance liquid chromatography (HPLC) analysis. Scanning tunneling microscopy investigations at the solid–liquid interface, corroborated by molecular modeling, made it possible to unravel the dynamic self-assembly of such systems into ordered supramolecular architectures, by visualizing and identifying the patterns resulting from three different isomers, thereby demonstrating that the multiphotochromism is retained when the molecules are confined in two dimensions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report the synthesis of a novel C3-symmetrical multiphotochromic molecule bearing three azobenzene units at positions 1, 3, 5 of the central phenyl ring. The unique geometrical design of such a rigid scaffold enables the electronic decoupling of the azobenzene moieties to guarantee their simultaneous isomerization. Photoswitching of all azobenzenes in solution was demonstrated by means of UV–vis absorption spectroscopy and high performance liquid chromatography (HPLC) analysis. Scanning tunneling microscopy investigations at the solid–liquid interface, corroborated by molecular modeling, made it possible to unravel the dynamic self-assembly of such systems into ordered supramolecular architectures, by visualizing and identifying the patterns resulting from three different isomers, thereby demonstrating that the multiphotochromism is retained when the molecules are confined in two dimensions. |
Jorge Leira-Iglesias Alessandra Tassoni, Takuji Adachi Michael Stich Thomas Hermans M Oscillations, travelling fronts and patterns in a supramolecular system Article de journal Dans: 2018, ISSN: 1748-3387, 1748-3395. @article{Hermans2018, title = {Oscillations, travelling fronts and patterns in a supramolecular system}, author = {Jorge Leira-Iglesias, Alessandra Tassoni, Takuji Adachi, Michael Stich,Thomas M. Hermans}, editor = {Nature Nanotechnology}, url = {http://www.nature.com/articles/s41565-018-0270-4}, doi = {10.1038/s41565-018-0270-4}, issn = {1748-3387, 1748-3395}, year = {2018}, date = {2018-10-15}, abstract = {Supramolecular polymers, such as microtubules, operate under non-equilibrium conditions to drive crucial functions in cells, such as motility, division and organelle transport1. In vivo and in vitro size oscillations of individual microtubules2,3 (dynamic instabilities) and collective oscillations4 have been observed. In addition, dynamic spatial structures, like waves and polygons, can form in non-stirred systems5. Here we describe an artificial supramolecular polymer made of a perylene diimide derivative that displays oscillations, travelling fronts and centimetre-scale self-organized patterns when pushed far from equilibrium by chemical fuels. Oscillations arise from a positive feedback due to nucleation–elongation–fragmentation, and a negative feedback due to size-dependent depolymerization. Travelling fronts and patterns form due to self-assembly induced density differences that cause system-wide convection. In our system, the species responsible for the nonlinear dynamics and those that self-assemble are one and the same. In contrast, other reported oscillating assemblies formed by vesicles6, micelles7 or particles8 rely on the combination of a known chemical oscillator and a stimuli-responsive system, either by communication through the solvent (for example, by changing pH7,8,9), or by anchoring one of the species covalently (for example, a Belousov–Zhabotinsky catalyst6,10). The design of self-oscillating supramolecular polymers and large-scale dissipative structures brings us closer to the creation of more life-like materials11 that respond to external stimuli similarly to living cells, or to creating artificial autonomous chemical robots12.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Supramolecular polymers, such as microtubules, operate under non-equilibrium conditions to drive crucial functions in cells, such as motility, division and organelle transport1. In vivo and in vitro size oscillations of individual microtubules2,3 (dynamic instabilities) and collective oscillations4 have been observed. In addition, dynamic spatial structures, like waves and polygons, can form in non-stirred systems5. Here we describe an artificial supramolecular polymer made of a perylene diimide derivative that displays oscillations, travelling fronts and centimetre-scale self-organized patterns when pushed far from equilibrium by chemical fuels. Oscillations arise from a positive feedback due to nucleation–elongation–fragmentation, and a negative feedback due to size-dependent depolymerization. Travelling fronts and patterns form due to self-assembly induced density differences that cause system-wide convection. In our system, the species responsible for the nonlinear dynamics and those that self-assemble are one and the same. In contrast, other reported oscillating assemblies formed by vesicles6, micelles7 or particles8 rely on the combination of a known chemical oscillator and a stimuli-responsive system, either by communication through the solvent (for example, by changing pH7,8,9), or by anchoring one of the species covalently (for example, a Belousov–Zhabotinsky catalyst6,10). The design of self-oscillating supramolecular polymers and large-scale dissipative structures brings us closer to the creation of more life-like materials11 that respond to external stimuli similarly to living cells, or to creating artificial autonomous chemical robots12. |
Aliprandi, Alessandro; Marco, Brian Di N; Cola, Luisa De "Transition metal complexes in ECL: diagnostics and biosensing" Article de journal Dans: Photochemistry, 46 , p. 319–351, 2018, ISBN: 978-1-78801-336-9. @article{Aliprandi2018, title = {"Transition metal complexes in ECL: diagnostics and biosensing"}, author = {Alessandro Aliprandi and Brian N. Di Marco and Luisa De Cola}, editor = {Photochemistry}, url = {https://doi.org/10.1039/9781788013598-00319}, isbn = { 978-1-78801-336-9}, year = {2018}, date = {2018-09-03}, journal = {Photochemistry}, volume = {46}, pages = {319–351}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Uzunov, N M; Melendez-Alafort, L; Bello, M; Cicoria, G; Zagni, F; De Nardo, L; Selva, A; Mou, L; Rossi-Alvarez, C; Pupillo, G; Di Domenico, G; Uccelli, L; Boschi, A; Groppi, F; Salvini, A; Taibi, A; Duatti, A; Martini, P; Pasquali, M; Loriggiola, M; Marengo, M; Strada, L; Manenti, S; Rosato, A; Esposito, J Radioisotopic purity and imaging properties of cyclotron-produced Tc-99m using direct Mo-100(p,2n) reaction Article de journal Dans: PHYSICS IN MEDICINE AND BIOLOGY, 63 (18), 2018, ISSN: 0031-9155. @article{uzunov_radioisotopic_2018, title = {Radioisotopic purity and imaging properties of cyclotron-produced Tc-99m using direct Mo-100(p,2n) reaction}, author = {Uzunov, N. M. and Melendez-Alafort, L. and Bello, M. and Cicoria, G. and Zagni, F. and De Nardo, L. and Selva, A. and Mou, L. and Rossi-Alvarez, C. and Pupillo, G. and Di Domenico, G. and Uccelli, L. and Boschi, A. and Groppi, F. and Salvini, A. and Taibi, A. and Duatti, A. and Martini, P. and Pasquali, M. and Loriggiola, M. and Marengo, M. and Strada, L. and Manenti, S. and Rosato, A. and Esposito, J.}, doi = {10.1088/1361-6560/aadc88}, issn = {0031-9155}, year = {2018}, date = {2018-09-01}, journal = {PHYSICS IN MEDICINE AND BIOLOGY}, volume = {63}, number = {18}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Gobbi, Marco ; Bonacchi, Sara ; Lian, Jian X; Vercouter, Alexandre ; Bertolazzi, Simone ; Zyska, Bjoern ; Timpel, Melanie ; Tatti, Roberta ; Olivier, Yoann ; Hecht, Stefan ; Nardi, Marco V; Beljonne, David ; Orgiu, Emanuele ; Samori, Paolo Collective molecular switching in hybrid superlattices for light-modulated two-dimensional electronics (vol 9, 3689, 2018) Article de journal Dans: NATURE COMMUNICATIONS, 9 , 2018, ISSN: 2041-1723. @article{gobbi_collective_2018-1, title = {Collective molecular switching in hybrid superlattices for light-modulated two-dimensional electronics (vol 9, 3689, 2018)}, author = {Gobbi, Marco and Bonacchi, Sara and Lian, Jian X. and Vercouter, Alexandre and Bertolazzi, Simone and Zyska, Bjoern and Timpel, Melanie and Tatti, Roberta and Olivier, Yoann and Hecht, Stefan and Nardi, Marco V. and Beljonne, David and Orgiu, Emanuele and Samori, Paolo}, doi = {10.1038/s41467-018-05541-6}, issn = {2041-1723}, year = {2018}, date = {2018-09-01}, journal = {NATURE COMMUNICATIONS}, volume = {9}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Publications (FR)
2019 |
Tuning the Optical and Electrical Properties of Few‐Layer Black Phosphorus via Physisorption of Small Solvent Molecules Article de journal Dans: Small, 15 , p. 1903432, 2019. |
Covalently linked donor–acceptor dyad for efficient single material organic solar cells Article de journal Dans: Chem. Commun, 55 , p. 14202–14205, 2019. |
From Supramolecular Chemistry to Complex Chemical Systems Article de journal Dans: Chem. Eur. J, 25 , p. 13229–13230, 2019. |
Dynamic covalent conjugated polymer epitaxy on graphene Article de journal Dans: J. Mater. Chem. C, 7 , p. 12240–12247, 2019. |
Liquid‐Gated Transistors Based on Reduced Graphene Oxide for Flexible and Wearable Electronics Article de journal Dans: Adv. Funct. Mater., 29 , p. 1905375, 2019. |
Boosting and Balancing Electron and Hole Mobility in Single- and Bilayer WSe2 Devices via Tailored Molecular Functionalization Article de journal Dans: ACS Nano, 13 , p. 11613–11622, 2019. |
Photomodulation of Two-Dimensional Self-Assembly of Azobenzene–Hexa-peri-hexabenzocoronene–Azobenzene Triads Article de journal Dans: Chem. Mater., 31 , p. 6979–6985, 2019. |
Controlling Ambipolar Transport and Voltage Inversion in Solution-Processed Thin-Film Devices through Polymer Blending Article de journal Dans: Chem. Mater., 31 , p. 6491–6498, 2019. |
Tuning graphene transistors through ad hoc electrostatics induced by a nanometer-thick molecular underlayer Article de journal Dans: Nanoscale, 11 , p. 19705–19712, 2019. |
Oxacycle‐Fused [1]Benzothieno[3,2‐b][1]benzothiophene Derivatives: Synthesis, Electronic Structure, Electrochemical Properties, Ionisation Potential, and Crystal Structure Article de journal Dans: ChemPlusChem, 84 , p. 1263–1269, 2019. |
π‐Conjugated Molecules: From Structure to Function Article de journal Dans: ChemPlusChem, 84 , p. 1177–1178, 2019. |
Enhancement of Charge Transport in Polythiophene Semiconducting Polymer by Blending with Graphene Nanoparticles Article de journal Dans: ChemPlusChem, 84 , p. 1366–1374, 2019. |
3D hybrid networks of gold nanoparticles: mechanoresponsive electrical humidity sensors with on-demand performances Article de journal Dans: Nanoscale, 11 , p. 19319–19326, 2019. |
Modulating the Charge Transport in 2D Semiconductors via Energy‐Level Phototuning Article de journal Dans: Adv. Mater., 31 , p. 1903402, 2019. |
Water-Dispersed High-Quality Graphene: A Green Solution for Efficient Energy Storage Applications Article de journal Dans: ACS Nano, 13 , p. 9431–9441, 2019. |
2D hybrid networks of gold nanoparticles: mechanoresponsive optical humidity sensors Article de journal Dans: Nanoscale, 11 , p. 19315–19318, 2019. |
Tailoring the physicochemical properties of solution-processed transition metal dichalcogenides via molecular approaches Article de journal Dans: Chem. Commun, 55 , p. 8900–8914, 2019. |
Charge transport enhancement in supramolecular oligothiophene assemblies using Pt(II) centers as a guide Article de journal Dans: J. Mater. Chem. A, 7 , p. 16777–16784, 2019. |
Unconventional Nanofabrication for Supramolecular Electronics Article de journal Dans: Advanced Materials, 31 (1900599), 2019. |
Production and Patterning of Liquid Phase–Exfoliated 2D Sheets for Applications in Optoelectronics Article de journal Dans: Advanced Functional Materials, 29 (1901126), 2019. |
A New Class of Rigid Multi(azobenzene) Switches Featuring Electronic Decoupling: Unravelling the Isomerization in Individual Photochromes Article de journal Dans: American Chemical Society, 141 , p. 9273−9283, 2019. |
Functionalization of 2D Materials with Photosensitive Molecules: From Light‐Responsive Hybrid Systems to Multifunctional Devices Article de journal Dans: Advanced Optical Materials, 7 , p. 1900286, 2019. |
Interface Engineering in Organic Devices Article de journal Dans: Advanced Materials Technologies, 4 (1900303), 2019. |
Synthesis and breakdown of universal metabolic precursors promoted by iron Article de journal Dans: Nature, 569 , p. 104-107, 2019. |
Tuning and controlling the shape of mesoporous silica particles with CTAB/sodium deoxycholate catanionic mixtures Article de journal Dans: MICROPOROUS AND MESOPOROUS MATERIALS, 279 , p. 423-431, 2019. |
Persian waxing of graphite: towards green large-scale production of graphene Article de journal Dans: Chem. Commun 2019, 55 , p. 5331-5334, 2019. |
Two-dimensional self-assembly and electrical properties of the donor-acceptor tetrathiafulvalene-polychlorotriphenylmethyl radical on graphite substrates Article de journal Dans: Journal of Applied Physics, 125 (142909), 2019. |
A Universal Approach toward Light-Responsive Two-Dimensional Electronics: Chemically Tailored Hybrid van der Waals Heterostructures Article de journal Dans: ACS Nano 2019, 13 (4), p. 4814-4825, 2019. |
Blue-emitting bolaamphiphilic zwitterionic iridium(iii) complex Article de journal Dans: DALTON TRANSACTIONS, 48 (11), p. 3664-3670 , 2019. |
Enhancement of the Electron−Phonon Scattering Induced by Intrinsic Surface Plasmon−Phonon Polaritons Article de journal Dans: ACS Photonics 2019, 6 (4), pp 1073–1081, 6 (4), p. 1073-1081, 2019. |
Nonvolatile Memories Based on Graphene and Related 2D Materials Article de journal Dans: Advanced Materials, 31 (Issue 10), p. 1806663, 2019. |
Thermally Limited Force Microscopy on Optically Trapped Single Metallic Nanoparticles Article de journal Dans: PHYSICAL REVIEW APPLIED , 11 ( 034023), 2019. |
Recreating ancient metabolic pathways before enzymes. Article de journal Dans: Bioorganic & Medicinal Chemistry, 2019. |
High‐Performance Graphene‐Based Cementitious Composites Article de journal Dans: ADVANCED SCIENCE, 6 (1801195), 2019. |
Optically switchable organic light-emitting transistors Article de journal Dans: Nature Nanotechnology, 14 , p. 347-353, 2019. |
Synthesis of new Mn19 analogues and their structural, electrochemical and catalytic properties Article de journal Dans: Dalton Transactions, (15), 2019. |
Tilting a ground-state reactivity landscape by vibrational strong coupling Article de journal Dans: Science, 363 (6427), p. 615-619, 2019. |
Nano-Subsidence-Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays Article de journal Dans: ACS Nano, 13 (2), p. 2654–2662, 2019. |
Novel Keplerate type polyoxometalate-surfactant-graphene hybrids as advanced electrode materials for supercapacitors Article de journal Dans: Energy Storage Materials, 17 (February 2019), p. p 186-193, 2019. |
Catalytic Transition Metal Systems for Functionalization of Unreactive Sites of Molecules Article de journal Dans: Nature Catalysis, 2 , p. 114-122, 2019. |
Doping of Monolayer Transition-Metal Dichalcogenides via Physisorption of Aromatic Solvent Molecules Article de journal Dans: J. Phys. Chem. Lett, 10 (3), p. 540-547, 2019. |
Graphene Oxide Hybrid with Sulfur–Nitrogen Polymer for High-Performance Pseudocapacitors Article de journal Dans: J. Am. Chem. Soc., 141 (1), p. 482-487, 2019. |
Molecule–Graphene Hybrid Materials with Tunable Mechanoresponse: Highly Sensitive Pressure Sensors for Health Monitoring Article de journal Dans: Advanced Materials, 31(1), 1804600, 2019. |
"Amino grafted MCM-41 as highly efficient and reversible ecofriendly adsorbent material for the Direct Blue removal from wastewater" Article de journal Dans: JOURNAL OF MOLECULAR LIQUIDS, 273 , p. 435-446 , 2019. |
"Highly degradable imine-doped mesoporous silica particles" Article de journal Dans: MATERIALS CHEMISTRY FRONTIERS, 3 (1), p. 111-119 , 2019. |
2018 |
Electronic Decoupling in C3-Symmetrical Light-Responsive Tris(Azobenzene) Scaffolds: Self-Assembly and Multiphotochromism Article de journal Dans: J. Am. Chem. Soc., 2018, 140 (47), 16062–16070, 2018. |
Oscillations, travelling fronts and patterns in a supramolecular system Article de journal Dans: 2018, ISSN: 1748-3387, 1748-3395. |
"Transition metal complexes in ECL: diagnostics and biosensing" Article de journal Dans: Photochemistry, 46 , p. 319–351, 2018, ISBN: 978-1-78801-336-9. |
Radioisotopic purity and imaging properties of cyclotron-produced Tc-99m using direct Mo-100(p,2n) reaction Article de journal Dans: PHYSICS IN MEDICINE AND BIOLOGY, 63 (18), 2018, ISSN: 0031-9155. |
Collective molecular switching in hybrid superlattices for light-modulated two-dimensional electronics (vol 9, 3689, 2018) Article de journal Dans: NATURE COMMUNICATIONS, 9 , 2018, ISSN: 2041-1723. |