采用活性层包覆法在自制超细 Sn O2 胶体粒子表面包覆 Ti O2 ,制备出 Sn O2 @Ti O2 包覆型复合催化剂 ,以其对有机磷农药 DDVP的降解效果作为评价光催化活性的标准 ,对制备条件进行了优化 ,并用 XRD、TEM和 BET等手段对样品进行了表征 .结果表明 ,Sn O2 胶体乙醇溶液含水量 2 0 % ,钛酸丁酯质量分数为3 4 .5% ,灼烧温度 680℃时制得 Ti O2 含量 56.4 5%的包覆样品 Sn O2 @Ti O2 为纳米级粒子 ,且其光催化活性最佳 The active layer coating method was used to coat Ti O2 on self-made ultrafine SnO2 colloidal particles to prepare SnO2 @Ti O2-coated composite catalyst, and its degradation effect on DDVP of organophosphorus pesticide was taken as the standard to evaluate photocatalytic activity , The preparation conditions were optimized and the samples were characterized by XRD, TEM and BET.The results showed that the content of water in 20% SnO2 colloidal ethanol solution and the mass fraction of butyl titanate was 34.5% When the sintering temperature is 680 ℃, the coated sample Sn O2 @Ti O2 with a Ti O2 content of 56.4 5% is a nano-sized particle and has the best photocatalytic activity