以纳米SnO2·nH2O胶体粒子为基质,采用活性层包覆法制备出复合光催化剂SnO2@TiO2.用其对有机磷农药DDVP的稀释液进行降解,并用SEM、TEM、XRD、BET和XPS等手段进行了表征.结果表明:SnO2@TiO2粒径在12nm左右,比表面积为72.27m2g,由锐钛型TiO2与金红石型SnO2组成,光催化活性明显优于单一的SnO2、TiO2.其最佳用量为3.0gL,并且可重复使用.添加剂H2O2、Fe3+的最佳浓度分别为1.65mmolL和0.5mmolL. The composite SnO2 @ TiO2 photocatalyst was prepared by the active layer coating method using nanometer SnO2 · nH2O colloidal particles as the substrate. The DDVP diluted solution of organophosphorus pesticide was degraded and characterized by SEM, TEM, XRD, BET and XPS The results show that the particle size of SnO2 @ TiO2 is about 12 nm and the specific surface area is 72.27 m2  g, which is composed of anatase TiO2 and rutile SnO2, and the photocatalytic activity is better than that of single SnO2 and TiO2. The dosage is 3.0gL, and can be reused.The optimum concentrations of H2O2 and Fe3 + are 1.65mmolL and 0.5mmolL, respectively.