纳米SnO2／TiO2／MMT制备及其光催化性能

Preparation of nano SnO_2/TiO_2/MMT and its photocatalytic reactivity

比较不同制备方法制得的复合催化剂，由超临界干燥法制备的光催化剂具有粒径小，分散性好，光催化活性高等特点．以TiCl4为原料，采用溶胶凝胶法结合超临界流体干燥法（SCFD）SU备了纳米级SnO2/TiO2／MMT（蒙脱土）复合光催化剂．采用XRD和TEM对样品进行了表征．结果表明：TiO2以锐钛矿型形式存在，催化剂粒径在13—20nm．以活性红X-3B溶液、活性橙K—NG和活性紫X-2R为反应模型，对所得催化剂的催化活性进行了评价，降解率分别达到99．9％、99．6％和99．5％，催化剂循环利用时仍具有较高的催化活性．

Compared with the composite photocatalysts, it was found that the photocatalysts prepared by SCFD method had small particle size, good dispersibility and high activity. SnO2/TiO2/MMT （montmorillonite） nanocomposite photocatalysts were prepared using TiCl4 as precursors by sol-gel method and supercritical fluid drying （SCFD） method. The catalysts were characterized by the means of XRD and TEM. The results showed that TiO2 existed in anatase type, and the catalyst particle size was 13-20 nm. The photocatalytic activity was e- valuated using Reactive Red X-3B, Reactive Orange K-NG and Reactive Violet X-2R as reaction models, and the degradation rate was 99.9%, 99.6% and 99.5%, respectively. The recycled catalyst still had high catalytic reactivity.