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Light-enhanced liquid-phase exfoliation and current photoswitching in graphene-azobenzene composites.

Döbbelin M, Ciesielski A, Haar S, Osella S, Bruna M, Minoia A, Grisanti L, Mosciatti T, Richard F, Prasetyanto EA, De Cola L, Palermo V, Mazzaro R, Morandi V, Lazzaroni R, Ferrari AC, Beljonne D, Samorì P - Nat Commun (2016)

Bottom Line: Graphene is at the centre of an ever-growing research effort due to its combination of unique properties.We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites.We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes.

View Article: PubMed Central - PubMed

Affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.

ABSTRACT
Multifunctional materials can be engineered by combining multiple chemical components, each conferring a well-defined function to the ensemble. Graphene is at the centre of an ever-growing research effort due to its combination of unique properties. Here we show that the large conformational change associated with the trans-cis photochemical isomerization of alkyl-substituted azobenzenes can be used to improve the efficiency of liquid-phase exfoliation of graphite, with the photochromic molecules acting as dispersion-stabilizing agents. We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites. We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes. These findings pave the way to the development of new optically controlled memories for light-assisted programming and high-sensitive photosensors.

No MeSH data available.


Related in: MedlinePlus

Evolution of Raman spectra on illumination.(a) Comparison of the Raman spectrum of a graphene/4-(decyloxy) azobenzene hybrid film after 90-min illumination with visible light, UV light and visible light again to probe the effect of isomerization. (b) The same experiment on azobenzene powder. (c) 4-(decyloxy)azobenzene Raman peaks C3, C4 and C5 extracted from graphs in a showing the change of peaks ratio on illumination, which confirms the isomerization. (d) Dependence upon illumination of I(C3)/I(C4) for both hybrid material and powders.
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f4: Evolution of Raman spectra on illumination.(a) Comparison of the Raman spectrum of a graphene/4-(decyloxy) azobenzene hybrid film after 90-min illumination with visible light, UV light and visible light again to probe the effect of isomerization. (b) The same experiment on azobenzene powder. (c) 4-(decyloxy)azobenzene Raman peaks C3, C4 and C5 extracted from graphs in a showing the change of peaks ratio on illumination, which confirms the isomerization. (d) Dependence upon illumination of I(C3)/I(C4) for both hybrid material and powders.

Mentions: Figure 4a plots the Raman spectra of a graphene–azobenzene film after visible and UV light illumination, acquired at 514.5 nm with power <250 μW to avoid any Raman laser-induced isomerization of azobenzene. None of the graphene Raman parameters show significant change on UV or visible light irradiation indicating negligible change in the defects and doping.


Light-enhanced liquid-phase exfoliation and current photoswitching in graphene-azobenzene composites.

Döbbelin M, Ciesielski A, Haar S, Osella S, Bruna M, Minoia A, Grisanti L, Mosciatti T, Richard F, Prasetyanto EA, De Cola L, Palermo V, Mazzaro R, Morandi V, Lazzaroni R, Ferrari AC, Beljonne D, Samorì P - Nat Commun (2016)

Evolution of Raman spectra on illumination.(a) Comparison of the Raman spectrum of a graphene/4-(decyloxy) azobenzene hybrid film after 90-min illumination with visible light, UV light and visible light again to probe the effect of isomerization. (b) The same experiment on azobenzene powder. (c) 4-(decyloxy)azobenzene Raman peaks C3, C4 and C5 extracted from graphs in a showing the change of peaks ratio on illumination, which confirms the isomerization. (d) Dependence upon illumination of I(C3)/I(C4) for both hybrid material and powders.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829665&req=5

f4: Evolution of Raman spectra on illumination.(a) Comparison of the Raman spectrum of a graphene/4-(decyloxy) azobenzene hybrid film after 90-min illumination with visible light, UV light and visible light again to probe the effect of isomerization. (b) The same experiment on azobenzene powder. (c) 4-(decyloxy)azobenzene Raman peaks C3, C4 and C5 extracted from graphs in a showing the change of peaks ratio on illumination, which confirms the isomerization. (d) Dependence upon illumination of I(C3)/I(C4) for both hybrid material and powders.
Mentions: Figure 4a plots the Raman spectra of a graphene–azobenzene film after visible and UV light illumination, acquired at 514.5 nm with power <250 μW to avoid any Raman laser-induced isomerization of azobenzene. None of the graphene Raman parameters show significant change on UV or visible light irradiation indicating negligible change in the defects and doping.

Bottom Line: Graphene is at the centre of an ever-growing research effort due to its combination of unique properties.We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites.We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes.

View Article: PubMed Central - PubMed

Affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.

ABSTRACT
Multifunctional materials can be engineered by combining multiple chemical components, each conferring a well-defined function to the ensemble. Graphene is at the centre of an ever-growing research effort due to its combination of unique properties. Here we show that the large conformational change associated with the trans-cis photochemical isomerization of alkyl-substituted azobenzenes can be used to improve the efficiency of liquid-phase exfoliation of graphite, with the photochromic molecules acting as dispersion-stabilizing agents. We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites. We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes. These findings pave the way to the development of new optically controlled memories for light-assisted programming and high-sensitive photosensors.

No MeSH data available.


Related in: MedlinePlus