采用溶胶-凝胶-溶剂热路径合成H3PW12O40/TiO2和H4SiW12O40/TiO2 及其光催化降解二硝基甲苯

以非离子表面活性剂P123为结构导向剂，采用溶胶-凝胶与溶解热相结合方法，制备了两类介孔材料H₃PW₁₂O₄₀/TiO₂和H₄SiW₁₂O₄₀/TiO₂，并对其进行了表征.?X射线粉末衍射和拉曼光谱分析表明，所制催化剂为锐钛矿晶型，体系中H₃PW₁₂O₄₀和H₄SiW₁₂O₄₀的Keggin结构经400?℃焙烧后仍保持完整.?H₃PW₁₂O₄₀/TiO₂和H₄SiW₁₂O₄₀/TiO₂的平均粒径分别为15.49和7.75?nm.?N₂吸附-脱附和扫描电镜结果表明，P123的加入使催化剂的粒径减小，比表面积和孔体积明显增大，其中H₃PW₁₂O₄₀/TiO₂和H₄SiW₁₂O₄₀/TiO₂的比表面积分别高达252.2和250.0?m²/g.?紫外漫反射吸收光谱表明，与纯TiO₂相比，复合催化剂的吸收光谱发生了明显的红移，且吸收强度明显增大.?催化剂对DNT降解实验表明，在最佳操作条件下降解率可高达95%.?

Photocatalysis of dinitrotoluene decomposition by H3PW12O40/TiO2 and H4SiW12O40/TiO2 prepared by a modified sol-gel synthesis and solvothermal treatment method

Mesoporous H₃PW₁₂O₄₀/TiO₂ and H₄SiW₁₂O₄₀/TiO₂ were synthesized by combining sol-gel technology using a nonionic surfactant P123 as a structure directing agent with solvothermal treatment. X-ray diffraction and Raman spectroscopy results indicated that the TiO₂ particles had the anatase phase, and the primary Keggin structures of H₃PW₁₂O₄₀ and H₄SiW₁₂O₄₀ remained intact after calcination at 400 ℃. N₂ adsorption-desorption analysis and scanning electron microscopy showed that the specific surface area and pore volume were increased by the addition of P123. The specific surface area of H₃PW₁₂O₄₀/TiO₂ and H₄SiW₁₂O₄₀/TiO₂ increased to 252.2 and 250.0 m²/g, respectively. Ultraviolet-visible absorption spectroscopy showed that compared with pure TiO₂, an obvious red shift occurred and the absorption intensity was increased for the composite catalysts. The catalysts were tested and the degradation rate of dinitrotoluene was as high as 95% under the optimum conditions.