复合催化剂H_4SiW_(12)O_(40)/TiO_2的制备及其光催化降解TNT研究  

On the preparation of H_4SiW_(12)O_(40)/TiO_2 and its photocatalytic activity for the trinitrotoluene decomposition

作　　者：尚海茹[1] 冯长根[2] 孙良[1] 甘强[2] 

机构地区：[1]北京理工大学数学学院,北京100081 [2]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《安全与环境学报》2016年第4期288-292,共5页Journal of Safety and Environment

基　　金：北京理工大学基础研究基金项目(20130242014;20150242007)

摘　　要：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。The paper aims at introducing its experience in successful synthesis of mesoporous materials known as H_4SiW_（12）O_（40）/TiO_2 by integrated application of the sol-gel technology and the solvo-thermal treating process. For the said research purpose,we have first of all carefully identified and determined the structure of the catalysts by X-ray diffraction（ XRD）,their optical absorption features were characterized by UV-Vis diffused reflection spectrum（ UV-Vis DRS）,the specific surface area,pore size and pore volume through the nitrogen adsorption-desorption analysis.The X-ray diffraction results demonstrate that the catalysts we have been working with are uniform in anatase phase. When the modification is done,the average crystal size of H_4SiW_（12）O_（40）/TiO_2 has been found reduced to 7. 75 nm. The UV-Vis diffused reflection spectrum have shown that the absorption wavelength of the composite film tends to be red-shifted with the enhance of the utility ratio of the light after H_4SiW_（12）O_（40）is doped in comparison with the pure TiO_2. At the same time,the analysis over the N2adsorption-desorption comparison and control indicates that the orderliness of the aperture has been remarkably intensified with the aggregation of the particles being inhibited effectively in comparison with TiO_2. Furthermore,the specific surface area and the pore volume increased by adding P123 to it,the specific surface area of H4 Si W12O40/ TiO_2（ 1 g P123） has been enlarged to 240. 36 m^2/ g from 179. 3 m^2/ g. Therefore,the enlarged surface area is now in a position to offer much greater active sites for the heterogeneous photocatalysis,which have been empowered with the higher photocatalytic dynamic activity. When we have investigated and examined the photocatalytic activities of the prepared catalysts via the degradation of the typical nitro-compound trinitrotoluene（ TNT）,we have made sure that the photocatalytic degradation of TNT is well in accord with the apparent first-order reaction. It

关 键 词：环境工程学 多金属氧酸盐 二氧化钛 光催化降解 三硝基甲苯 

分 类 号：X703.1[环境科学与工程—环境工程]