Photocatalytic activity of lanthanum and sulfur co-doped TiO2 photocatalyst under visible light

A novel lanthanum and sulfur co-doped TiO2 photocatalyst was synthesized by precipitation-dipping method, and characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and UV-Vis diffuse reflectance spectroscopy. Compared with the S-doped TiO2, La-doped TiO2 and the standard Degussa P25 photocatalysts, the lanthanum and sulfur co-doped TiO2 photocatalyst (the molar percentage of La is 3.0%) calcined at 450 degrees C for 2 h showed the strongest absorption for visible light and highest activities for degradation of reactive blue 19 dye in aqueous solution under visible light(lambda>400 nm) irradiation. It was also discovered that the co-doping of lanthanum and sulfur hindered the aggregation and growth of TiO2 particles, and the doping of lanthanum reduced slightly the phase transition temperature of TiO2 from anatase to rutile.