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New visible-light driven plasmonic photocatalysts

Rémi Dessapt (MC), Hélène Serier-Brault (MC), Stéphane Jobic (DR), Khadija Hakouk (PhD student)

Ag@metal-oxide semiconductor hybrid nanostructures are plasmonic photocatalysts which combine the localized surface plasmon resonance of the silver metal nanoparticles (NPs) with photoinduced electron transfers into the metal oxide. These materials are of great interest in visible-light induced water splitting, pollutant destruction and bacterial disinfection.We develop a new strategy for the synthesis of plasmonic nanostructures by an « all solid-state » photodeposition method from photoresponsive silver polyoxometalates. The 1D nanocomposite Ag@Ag2Mo3O10.2H2O (Figure 1) is in-situ elaborated by exposing Ag2Mo3O10∙2H2O ultrathin nanowires under a low-power UV irradiation. Quasi spherical silver metal NPs with an average diameter around 10 nm are photogenerated at the surface of the semiconductor according to a mechanism which implies the concomitant reduction of Ag+ and Mo6+ ions. This novel approach is a promising alternative to classical photodeposition methods involving solid-liquid interfaces.

Extreme nanowires

Eric Faulques (DR)

Achieving confined crystal growth in one dimension (1D) of semiconducting and insulating materials inside small diameter carbon nanotubes is a topic of great physical interest which has been successfully realized by several groups in the world using various synthesis methods. These tiny 1D crystals have no analogues in the 3D realm and their bulk physical properties can be profoundly changed by encapsulation. British scientists at the University of Warwick have coined these crystalline structures “extreme nanowires” since they are ultimately thin (one or two-atom thick for the smallest diameters). Furthermore, filled carbon nanotubes can have their own electronic properties drastically modified due to the charge transfer induced by electron-donor or electron-acceptor fillers. Aside from molecular species, clusters, fullerenes, graphene nanoribbons, and elemental forms, a wide variety of binary crystals have been encapsulated in carbon nanotubes like oxides/hydroxides, metal halides, and chalcogenides.

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