Synthesis and characterization of Fe-doped sulfated titania with high photocatalytic activity in visible light

Fe-doped sulfated titania (FST) photocatalysts with high photocatalytic activity under visible light irradiation were prepared by one-step thermal hydrolysis of industrial titanyl sulfate and characterized by use of XRD, FT-IR, UV-visible DRS, XPS, and N-2 adsorption-desorption. The effect of total titanium concentration on the structure of the titania photocatalysts was investigated. The photocatalytic activity of FST samples was evaluated by studying the photooxidation of methylene blue in aqueous solution under irradiation with UV light or visible light. The results indicate that Fe-doping can effectively reduce the apparent band gap energy of titania and consequently extend the spectral response range to visible light. In addition, Fe-doping is beneficial to dissociation of adsorbed H2O, and subsequent formation of surface hydroxyl groups, and promoting the separation of photogenerated electrons and holes. Sulfation has effects of orienting, stabilizing, and supporting the mesoporous structure, and also effectively increases surface acidity. All these effects enhance the photocatalytic activity of FST samples.