Effects of surface modification and doping on the photocatalytic activity of TiO2

The photocatalytic activity of titanium dioxide prepared by different synthetic routes, including flame spray pyrolysis, and modified either by noble metal nanoparticles deposition or by surface fluorination, or by doping with non metal p-block elements was tested in both down-hill and up-hill reactions, including the degradation of organic molecules in water suspension and the parallel hydrogen peroxide production by oxygen reduction and hydrogen production from water splitting or methanol steam reforming. Photoactivity results are discussed in relation to the structure and absorption properties of the photocatalytic materials, which may affect the photocatalytic electron transfer paths. Selected examples include the effect of gold nanoparticles deposition on the photocatalytic oxidation of organic substrates, the effect of fluorine doping on the absorption and action spectra of the materials, the effects of noble metal nanoparticles deposition and of the inlet alcohol/water composition on the reaction paths involved in the photo-steam reforming methanol.