复合催化剂SO_4^(2-)-H_3PW_(12)O_(40)/TiO_2(P123)的制备及其光催化降解二硝基甲苯  

Preparation of SO_4^(2-)-H_3PW_(12)O_(40)/TiO_2(P123) and It's Photocatalytic Activity for Dinitrotoluene Decomposition

作　　者：尚海茹[1] 刘霞[2] 冯长根[1] 

机构地区：[1]北京理工大学爆炸科学与技术国家重点实验室,北京100081 [2]中国农业大学理学院,北京100193

出　　处：《科技导报》2013年第36期20-25,共6页Science & Technology Review

基　　金：中国工程物理研究院化工材料研究所资助项目;《科技导报》博士生创新研究计划资助项目(kjdb2011005)

摘　　要：采用溶胶-凝胶与溶剂热相结合的方法制备了系列介孔复合光催化剂SO42--H3PW12O40/TiO2(P123),并对其进行了表征和分析。N2吸附表面分析及扫描电镜(SEM)图片显示,复合催化剂的粒径明显减小,比表面积高达211m2/g,是TiO2的5倍。紫外漫反射吸收光谱(UV-Vis)显示,与TiO2相比,复合催化剂的吸收光谱发生了明显的红移,且吸收强度明显增强。运用L16(45)的正交实验设计探讨了H3PW12O40负载量、模板剂P123的添加量、溶液初始pH值、催化剂加入量以及H2SO4浓度5个因素对二硝基甲苯(DNT)降解性能的影响,并对正交实验结果进行了直观分析和方差分析。结果表明,该降解过程符合L-H表观一级反应动力学,在催化剂用量为1.2g/L、H3PW12O40负载量为20%、模板剂P123的加入量为2g、溶液初始pH为2、H2SO4的浓度为1mol/L条件下,经氙灯光源辐照4h后,DNT的降解率达到98.7%,DNT降解的半衰期为0.7162h,取得了良好的光催化效果。Mesoporous materials SO^2-4-H3PW,2O40/TiO2（P123）were synthesized by combining sol-gel technology and solvothermal treatment. Nitrogen adsorption-desorption analysis and Scanning Electron Microscopy （SEM） results suggest that the specific surface area of SO^24-- H3PW,2040/TiO2 （2gP123） is 21 l m^2/g, which is five times higher than that of pure TiO2. The average particle size of composite catalyst decreases obviously. Results of ultraviolet-visible absorption spectra （UV-Vis） show that, compared with pure TiO2, an obvious redshift of composite catalysts was observed and the absorption intensity of the band increased significantly. By means of the orthogonal design method of L6（45）, the influence of various operating parameters on the dinitrotoluene （DNT） degradation were investigated, including H3PW12O40 loadings, dosage of template agent P123, initial pH value of the solution, catalyst dosage and the concentration of H2SO4, then the intuitionistic analysis and variance analysis were performed. Kinetics results show that the photocatalytic degradation of DNT fits the apparent first-order reaction. The conversion of DNT reached 98.7% after xenon lamp irradiating for 4h under optimum operating conditions： 1.2g/L catalyst dosage, 20% H3PWt2040 loading, 2g dosage of P123, pH value 2 and lmol/L H2SO4. The half-life of DNT degradation is 0.7162h. The experimental results demonstrate that the photocatalytic effect is good.

关 键 词：多金属氧酸盐 二氧化钛 光催化 二硝基甲苯 正交设计 

分 类 号：X703[环境科学与工程—环境工程] O643.32[理学—物理化学]