Preparation of WOx-TiO2 and the Photocatalytic Activity under Visible Irradiation

Nanocrystalline tungsten oxide doped titanium dioxide (WOx-TiO2) powders were prepared by TiCl4 hydrolysis and characterized by XRD, XPS, UV–Vis absorption spectra and TEM. Results showed that WOx not only hindered the growth of TiO2 particles but also greatly increased the transformation temperature (>800 oC) from anatase to rutile during sintering; the dominant fraction of tungsten oxides was non-stoichiometric tungsten oxide (WxOy) with Wn+ (4