Photocatalytic activity of Sn-doped ZnO synthesized via peroxide route

ZnO*ZnO2 mixture was prepared by thermal hydrolysis of a zinc peroxo-complex precursor in presence of Sn2+ and Sn4+ ions. The effect of different tin valence states on structure and photocatalytic properties of the resulting products was investigated. All samples before annealing contained ZnO2 and except one sample also SnO2. Microstructural analysis showed a difference in morphology between the two sets of samples. A difference was also observed for the specific surface area. The photocatalytic decolorization of Orange II dye was employed to determine the photocatalytic activity of the samples; Sn2+ doped samples were more active than Sn4+ doped ZnO samples. Temperature 600 degrees C was optimal for annealing - the sample ZnP150Sn(2) annealed at 600 degrees C had the highest rate constant (0.0730 min (-1)) among the samples. Additional increase of Sn2+ amount led to further increase in rate constant (0.0937 min (-1) for the sample ZnP200Sn2) up to a certain point.