F Polycrystalline TiO2 is the most used photocatalyst due to his (photo)stability, non toxicity, and cheapness. The anatase phase is generally the most photoactive allotropic phase.
F Other semiconductors (ZnO, WO3, CdS, Fe2O3, ecc.) show lower photoactivity or problems linked to their non stability and anodic corrosion under irradiation.
F Liquid-solid or gas-solid interfaces play an important role on the determination of reaction mechanism, quantum yield and deactivation of the photocatalyst. The presence of water can influence the photocatalytic process.
F Several applications of photocatalysis are present nowadays. Purification of water and air, films of TiO2 and so on. Some examples commercially available are reported in the following.