电导法研究TiO2溶胶对水中微量氯代甲烷的光催化脱氯的作用

利用二氧化钛溶胶进行光催化氯代甲烷的水溶液．二氯甲烷、三氯甲烷、四氯甲烷溶液在二氧化钛溶胶和紫外光的作用下，分解产生氯化氢的水溶液，氯离子和氢离子使溶液的电导率增大．在光催化二氯甲烷和三氯甲烷溶液时，二氧化钛溶胶的浓度与电导率的变化值有一定的关系．当二氧化钛的浓度过高时，光照所产生的自由基和氧空穴对中间产物作用导致二氯甲烷的降解反应速度变缓，反映在电导率的变化上，电导率的增加速度变缓．选择合适的二氧化钛的浓度，将有利于二氯甲烷和三氯甲烷的光催化脱氯．随着甲烷上氯取代度的增加，催化剂对其的催化脱氯效果依次降低，光催化效果依次为：二氯甲烷、三氯甲烷和四氯甲烷．

Photo-catalytic De-chlorination of Chlorinated Methane by Titanium Oxide Sol

Titanium oxide sol was prepared by using inorganic titanium salt, and was used to photo-oxidize chloroform and chlorinated methane solution. Conductivity of solution was increased when chlorinated methane degraded under UV radiating. Addition of titanium oxide sol makes the degradation rate of chlorinated methane greater, and the conductivity will be changed. But when the added amount of the sol to solution is too much, the change rate of conductivity will be reduced for the reduced photo-oxidation of dichloromethane and trichloromethane. Suitable addition amount of the sol is benefit to photo-catalytic de-chlorination of dichloromethane and trichloromethane in solution.