纳米TiO_2/硅藻土复合光催化材料的制备与表征

Preparation and Characterization of Composite Photo-catalytic Material of Nano-TiO_2/Diatomite

采用酸浸法对硅藻土进行了提纯处理,以四氯化钛为前驱体,用水解沉淀法对提纯前后的硅藻土分别进行了表面包覆改性,制备了硅藻土负载TiO2复合光催化材料.通过SEM、XRD等测试手段对复合材料的成分、物相、形貌等进行了表征,并用甲基橙溶液的光催化降解率对材料的光催化性能进行了评价.结果表明,负载在硅藻土表面的TiO2晶型为锐钛型,晶粒平均尺寸12nm,纳米TiO2在硅藻土表面形成了均匀的包覆;这种硅藻土负载纳米TiO2复合光催化材料具有很强的光催化活性,对10mg/L的甲基橙溶液1.5h的脱色率达99%以上.

The diatomite was leached with sulfuric acid to remove impurity.The composite photo-catalytic material of nano-TiO2 and diatomite was prepared by surface modification of crude and purified diatomite with TiCl4 hydrolization.The chemical composition,phase and morphology of composite material were characterized by XPS,XRD and SEM,and the activity of this composite material was evaluated by photo-catalytic decoloration rate of methyl orange solution.The characterization results show that the nano-TiO2 was coated on the surface of diatomite,the crystal of TiO2 was anatase,and the average crystal size was 12 nm.The composite photo-catalytic material of nano-TiO2/purified diatomite had stronger photo-catalytic activity for methyl orange solution,and the decoloration rate was above 99% after 1.5 h photo-catalytic degradation.