【摘要】 硅藻土是一种天然生物成因的SiO₂.采用硅藻土做载体,用溶胶一凝胶法制备TiO₂/硅藻土复合光催化剂,TiO₂呈薄膜状负载在硅藻土上,部分团聚成颗粒状.在紫外光条件下负载TiO₂硅藻土对亚甲基蓝具有良好的光催化降解性能,36h后对亚甲基蓝的脱除率为90%,48h达到98%,降解效果好.纯硅藻土48h后对亚甲基蓝的脱除率仅为35%左右.负载TiO₂硅藻土对亚甲基蓝的光降解性能受TiO₂的同质多像结构影响.随着锐钛矿含量增加,负载TiO₂硅藻土的光降解性能增强.但是,当温度进一步升高,TiO₂由锐钛矿型转化为金红石型,负载TiO₂硅藻土的光降解性能随之降低.添加H₂O₂明显提高亚甲基蓝溶液的降解效果.更多还原

【Abstract】 TiO₂-mounted diatomite photocatalysts were prepared by a sol-gel method with diatomite support,a kind of natural biological diatomaceous silica earth.SEM observation shows that TiO2 is well mounted on the surface of diatomite as films and some particles. TiO2-mounted diatomite decomposes efficiently methylene blue （MB） under UV irradiation.Within 36h irradiation,about 90% MB is decomposed by TiO₂/diatomite photocatalyst.After 48h irradiation,MB is decomposed ahnost completely （about 98%）.However only 35% MB is decomposed by pure diatomite after 48h irradiation. With the increasing heat-treatment temperatures,the photocatalytic activity of the TiO₂/diatomite is increased with the formed anatase type of TiO₂ increasing,but decreased with rutile type of TiO₂ formed at 700℃C and 900℃.Adding H₂O₂ in MB solution can improve the efficiency of the TiO₂- mounted diatomite photocatalysts greatly.更多还原