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采用溶胶-凝胶与溶剂热相结合的方法制备了一系列介孔复合光催化剂H_4SiW_(12)O_(40)/TiO_2。通过X射线粉末衍射(XRD)、紫外-可见漫反射光谱(UV-Vis DRS)和N2吸附-脱附等检测技术对复合催化剂的组成结构、光学吸收特性及比表面积、孔径和孔容进行了表征。X射线粉末衍射分析表明,所制备的催化剂均为典型的锐钛矿晶型。紫外漫反射吸收光谱表明,与纯TiO_2相比,复合催化剂的吸收波长发生了明显红移,一定程度上拓宽了催化剂的光响应范围。N2吸附-脱附结果表明,与TiO_2相比,所制备的复合催化剂的孔径和有序性大幅度提高,粒子的聚集度明显降低。以炸药废水中典型有机污染物三硝基甲苯(TNT)为目标化合物,对所制备的复合催化剂的光催化活性进行了研究。结果表明,H4Si W_(12)O_(40)/TiO_2经修饰改性后,TNT废水中的COD降解率由70.22%提高至95.97%,反应半衰期由4.968 8 h降至1.916 4 h。
A series of mesoporous composite photocatalysts H_4SiW_ (12) O_ (40) / TiO_2 were prepared by sol - gel and solvothermal methods. The structure, optical absorption properties and specific surface area, pore size and pore volume of the composite catalysts were characterized by X-ray powder diffraction (XRD), UV-Vis DRS and N2 adsorption-desorption Characterization. X-ray powder diffraction analysis showed that the prepared catalysts are all typical anatase crystal forms. UV diffuse reflectance absorption spectra show that compared with pure TiO 2, the absorption wavelength of the composite catalyst shows a significant red shift, to a certain extent, broaden the light-response range of the catalyst. N2 adsorption - desorption results show that compared with TiO2, the prepared composite catalyst pore size and orderly increased significantly, the particle aggregation decreased significantly. The photocatalytic activity of the prepared composite catalyst was studied using TNT, a typical organic pollutant in explosive wastewater. The results showed that the COD degradation rate of TNT wastewater increased from 70.22% to 95.97% after H4Si W 12 O 40 / TiO 2 was modified and modified, and the half-life of reaction decreased from 4.968 8 h to 1.916 4 h.