Influence of platinum nano-particles on the photocatalytic activity of sol-gel derived TiO2 films

International audienceDifferent 1-step or 2-step photo-platinization methods have been implemented to load sol-gel TiO2 photocatalytic thin films with platinum nano-particles. These methods enable flexible variations in the amount of loaded particles, and they strongly influence the structure and size of these particles and the morphology of derived platinized films. The photocatalytic activity of platinized films has been studied. It is shown that optimal platinization conditions allow envisaging thin film photocatalysts with enhanced properties. Best performances are reached when the films are loaded with platinum particles for 30 or 60 min using a 1-step platinization method, which yields photocatalytic activities about 4 times greater than that of non-platinized films. Photocatalytic activity differences induced by the 1-step or 2-step photo-platinization methods are discussed in relation to the amount of loaded platinum together with structural and morphological features

Micro-structuration of a sol-gel architecture for channel waveguide / diffraction grating coupling

International audienc

Morphology-wettability relations in artificially structured superhydrophilic TiO2-SiO2 composite films

International audienceNaturally superhydrophilic TiO2-SiO2 composite films were deposited through a sol-gel route and the morphology of these films was artificially modified by nanosphere lithography using polystyrene spheres. Morphology changes induced by this structuration were studied by optical, scanning electron, and atomic force microscopy. The water wettability of the so-obtained films over aging under ambient atmosphere was then studied with respect to the sol composition and morphological features. This study i/confirms the assumption of a natural superhydrophilicity of composite films intrinsically induced by TiO2-SiO2 granular interfaces and ii/shows that this property can be greatly improved by artificially induced morphology features. Such features are discussed on the basis of well-established surface thermodynamic models

Nanocomposite and nanostructured coatings for LED lighting and photocatalytic applications.

International audienc

Superhydrophobic TiO2 coatings formed through a non-fluorinated wet chemistry route.

International audienceWe present a facile and low cost non-fluorinated wet chemistry route yielding rough and highly hydrophobic surfaces. This procedure is based on a nanosphere lithography (NSL) method using polystyrene (PS) spheres. Multilayer PS coatings were impregnated with a sol-gel TiO2 polymeric sol and then heat-treated at 500 degrees C. Derived NSL-structured TiO2 coatings were then grafted with hexadecyl trimethoxysilane (C16). The morphology of structured coatings was analyzed by optical, scanning electron, and atomic force microscopy, and the water wettability of TiO2 coating grafted with the C16 precursor was studied with respect to NSL features. It is shown that the synergy between the hydrophobicity imparted by the C16 precursor and roughness effects arising from NSL structuration leads to superhydrophobic coatings. In optimized conditions, the static contact angle of 11.6 mu L water droplets deposited on the surface is around 160 degrees with a corresponding tilt angle as low as 1 degrees. (C) 2013 Elsevier B.V. All rights reserved

Revêtements nano-composites nanofils / nanoparticules destinés à l’éclairage à LEDs et à la photocatalyse,

National audienc

Revêtements nano-composites nanofils / nanoparticules destinés à l’éclairage à LEDs et à la photocatalyse,

National audienc

Development of sol-gel derived ZnO nanowires (NWs) arrays for optical applications.

International audienc

Enhancement of the light extraction efficiency of sol-gel derived YAG:Ce coatings using ZnO nanowires (NWs) array.

International audienc

Elaboration of multiscale nanostructured luminescent coatings by combining ZnO nanowires and Y3Al5O12:Ce3+ luminescent coatings.

International audienc