Preparation and characterization of ZnO/TiO2, SO42−/ZnO/TiO2 photocatalyst and their photocatalysis

A novel binary oxide photocatalyst ZnO/TiO2 was prepared by a new modified sol–gel method using citric acid as a complex reagent and its photocatalytic activity was investigated. The factors, such as the ratio of amount of doped zinc ion, the precursors, and the calcination temperature on the activities of ZnO/TiO2 photocatalyst, were investigated. SO42−/ZnO/TiO2 was prepared by sulfating the dry gels of ZnO/TiO2 with H2SO4 solution. It was showed that the addition of ZnO could enhance the activity significantly, and sulfating ZnO/TiO2 with sulfuric acid resulted to dramatic enhancement, the degradation ratio of methyl orange could be up to 71.9%, compared with 55% of degradation of ZnO/TiO2 catalyst.