Effect of Sn-doping on Photocatalytic Activity of TiO2 Film for Degradation of Phenol

We prepared TiO2 (anatase) and Sn-doped TiO2 nanoparticlate film by Plasma-enhanced Chemical Vapor Deposition (PECVD) method. XRD and XPS experiments showed that Sn was doped into the lattice of TiO2 with a ratio of n (Sn) : n (Ti) =1 : 10. Sn-doping largely enhanced the photocatalytic activity of TiO2 film for phenol degradation. The enhancement in photoactivity by doping was discussed, based on the characterization with AFM, FTIR and EFISPS. Sn-doping produced localized level of Sn4+ in the band gap of TiO2, about 0. 4 eV below the conduction band, which could capture photogenerated electrons and reduce Oz adsorbed on the surface of TiO2 film, thus accelerated the photocatalytic reaction.