TiO_2薄膜光催化氧化降解苯的研究

Studies on the Photodegradation of Benzene on TiO_2 Thin Film

用溶胶 凝胶法制备出薄膜型TiO2催化剂,利用XRD,Raman,SEM和UV Vis等手段对催化剂进行表征,并考察了光催化降解苯的活性和降解主要产物CO,CO2的生成速率.结果表明,制得的薄膜型TiO2颗粒均匀致密,平均粒径为30～40nm,550℃焙烧后全部晶化为锐钛矿晶型.苯的降解反应表明TiO2膜的厚度对催化剂活性有显著影响,薄膜的最佳厚度为480nm,在180min时苯降解率达91.5%,CO和CO2的生成反应属于表观零级反应.同时还对反应动力学及反应机理作了初步探索.

The TiO_2 film was prepared by using sol-gel method with Ti(OC_4H_9)_4 as a precursor, and characterized by means of XRD, Raman, SEM and UV-Vis.The results showed the TiO_2 film was densified and the film uniformity was good.The average grain size of the film was 30—40 nm,and the sample calcinated at 550 ℃ was crystallized into anatase phase entirely.Photodegradation of benzene on TiO_2 film was investigated.The experiment results indicated the film thickness had a significant influence on the activity of the photocatalyst and the optimal thickness was 480 nm.The conversion of benzene was 91.5% after 180 min and the generation of CO, CO_2 followed zero-order kinetics.In the meantime,the kinetics and mechanisms of the photodegradation of benzene were discussed.