No abstract

Numerous kinds of photocatalysts such as oxide-, nitride-or sulfide-based semiconductors, conducting polymers or graphene oxide based materials have emerged since the discovery of water splitting on TiO electrodes in . Yet, metal-oxides are still largely the main family of materials promoted into photocatalytic applications.In this chapter, we focus on the application of supported nanostructures of metal oxides, principally TiO and ZnO, for the heterogeneous photocatalysis. We emphasize the benefits of increasing the specific surface area by using the direct growth of metal-oxide nanostructures onto porous templates. "mong the numerous strategies to improve the photocatalytic activity, we detail the fabrication of semiconductor metal-oxide heterostructures promoting the charge separation under UV irradiation. We also describe how the use of plasmonic nanostructures allows the shifting of the light absorption in the visible range. Finally, we give an overview on the new strategies to increase the photocatalytic activity with new architectures and materials based on metal-oxides.

In this work, we have evidenced the impact of stoichiometry on the photocatalytic properties of ZnO nanofilms grown by atomic layer deposition (ALD).

The reversibility of redox processes is an important function for sensing and molecular electronic devices such as pH reporters or molecular switches. Here we report the electrochemical behaviour and redox reversibility of para-aminothiolphenol (PATP) after different polymerisation methods. We used electrochemical and photo-polymerisation in neutral buffers and plasma polymerisation in air to induce reversible redox states. The chemical stoichiometry and surface coverage of PATP in the polymerized layers were characterized by X-ray photoelectron spectroscopy (XPS), while cyclic voltammetry (CV) was used to measure the charge transfer, double layer capacitance and electrochemical rate of the layers during successive potential cycles. Our results show that the surface coverage of the redox active species is higher on electro-polymerised samples, however, after consecutive cycles all the methods converge to the same charge transfer, while the plasma polymerised samples achieve higher efficiency per molecule and UV polymerised samples have a higher electron transfer rate.