载Ag-TiO_2/浮石光催化性能及耐用性考察

Study on photo-catalyzing performance and durability of Ag-TiO_2/pumice

采用天然浮石作为TiO2的载体,以溶胶—凝胶法制备TiO2/浮石,并将银沉积在TiO2表面制得载Ag-TiO2/浮石光催化剂。利用XRD、SEM进行表征,考察了载Ag-TiO2/浮石的光催化性能及其耐用性能。结果表明,载Ag-TiO2/浮石对质量浓度为10 mg/L的亚甲基蓝溶液具有良好的光催化降解效果,30 min时降解率超过90%。在反复使用30次之后,反应30 min时的降解率由最初的91.5%下降到75.1%,但经再生后即可恢复其活性,说明所制备的催化剂在多次使用后存在一定程度的化学失活。扫描电镜下观察使用60次的载Ag-TiO2/浮石表面的薄膜基本完好。

Ag-TiO2/pumice has been prepared by using natural pumice as the carrier of TiO2, TiO2/pumice prepared by sol-gel method and Ag loaded on the surface of the TiO2 film. It is characterized by XRD and SEM. The photocatalyzing performance and durability of loaded Ag-TiO2/pumice are studied and investigated. The results show that loaded Ag-TiO2/pumice has very good photo-catalysis/degradation efficiency on the 10 mg/L methylene blue solution. It takes 30 minutes to degrade above 90% of the methylene blue. After Ag-TiO2/pumice has been used repeatedly 30 times, and reacted for 30 min, the degrading rate of the catalyst decreases from 91.5% to 75.1%, but after the regeneration,its activity can be recovered. It shows that the chemical deactivation of the photo-catalysts occurs to a certain extent after being used many times. It is observed under SEM that the surface film of loaded Ag- TiO2/pumice basically keeps intact, after having been used 60 times.