Abstract: | Titanium dioxide semiconductor systems with excellent stability of photo-electric chemistry, no poison, cheap, and high separation efficiency of photogenerated charges, consequently, high photocatalytic activity, have been the subject of extensive investigation because of their promise in the photovoltaic[1], photocatalytic[2], and battery applications[3]. The efficiencies of these materials in photovoltaic and photocatalytic applications depend strongly upon the trapping and recombination energetics, i.e., electrons and holes and the conversion of light. Nanosized TiO2 particles present much higher photocatalytic activity due to larger effective surface areas, higher densities of. surface states, shorter distance of photogenerated charges from inner to the surfaces of TiO2 particles resulting in higher separation efficiency of electron-hole pairs, and quantum size effect. |