WO3 Coupled P-TiO2 Photocatalysts with Mesoporous Structure

A series of WO3 coupled P-doped TiO2 photocatalysts with mesoporous structure were synthesized by the decomposition of the doped H3PW12O40 precursor in the framework of TiO2. The effects of P doping and WO3 coupling on the structures, surface acidity, and optical properties of TiO2 were investigated by TGA, DSC, FT-IR, XRD, NH3-TPD, SEM, TEM, XPS, UV-Vis DRS, PL, and BET surface areas. Results show that the presence of phosphorus adds thermal stability to the mesoporous TiO2 framework and addition of WO3 greatly increases the Lewis acidity of the catalyst, which leads to a higher affinity for the reaction molecules. Moreover, WO3 coupling and P doping extent light response to the visible region due the formation of extra energy levels within the band gap. The samples show high visible light photocatalytic efficiency for the degradation of methylene blue. This is mainly attributed to good visible light absorption, high adsorption affinity toward organic molecules and the low recombination rate of photogenerated electron/hole pairs.