The thin films of TiO2 doped by Sn or Nb were prepared by sol-gel method under process control. The effects of Sn and Nb doping on the structural, optical, and photo-catalytic properties of applied thin films have been studied by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and UV-Vis absorption spectroscopy. Surface chemical state of thin films was examined by atomic X-ray photoelectron spectroscopy (XPS). XRD results suggest that adding impurities has a great effect on the crystallinity and particle size of TiO2. Titania rutile phase formation in thin film was promoted by Sn4+ addition but was inhibited by Nb5+ doping. The activity of the photocatalyst was evaluated by photocatalytic degradation kinetics of aqueous methylen Blue (MB) under UV and Visible radiation. The results show that the photocatalytic activity of the Sn-doped TiO2 thin film have a larger degradation efficieny than Nb-doped TiO2 under visible light, but under UV light photocatalytic activity of the Nb-doped TiO2 thin film is better.
