Fe^(3+)和Ce^(3+)掺杂对TiO_2光催化剂性能的影响

Effcts of Fe^(3+) and Ce^(3+) doping on photocatalytic performance of TiO_2 photocatalysts

采用溶胶凝胶法在玻璃纤维上涂层TiO2光催化剂,并掺杂Fe3+和Ce3+修饰TiO2光催化剂,进行了间歇式光催化降解气相苯实验,结果表明掺杂Fe3+和Ce3+均可以提高TiO2光催化剂的活性,其中0.2%Fe3+/TiO2光催化剂活性最好.借助XRD、SEM和XPS等表征手段来分析修饰前后的催化剂表面的物理化学性质变化,研究表面性质的变化对于光催化性能的影响.表征结果显示载体玻璃纤维表面均匀分布了粒径为40～60nm的锐钛型TiO2微粒,0.2%Fe3+和Ce3+掺杂后催化剂表面Ti3+浓度增大,表面羟基浓度减小.催化剂表面的Ti3+会与被吸附氧气反应形成Ti4+并同时产生活性组分O-2,氧化剂O-2在光催化降解苯反应过程中起着重要作用.

TiO2 catalysts on glass fibres were prepared by the sol-gel method, and then 0.2%o Fe^3＋ and Ce^3＋ were doped to modify the TiO2 photocatalysts. Experiments of the batch photocatalytic degradation of benzene were carried out, and the results indicated that Fe^3＋ and Ce^3＋ doping could improve the photocatalytic activity of the TiO2 catalysts, of which the 0.2% Fe^3＋/TiO2 photocatalyst was the best. XRD, SEM and XPS were used to analyze physical and chemical variation of TiO2 catalyst surfaces after Fe^3＋ and Ce^3＋ doping. The results showed that 40-60 nm size TiO2 anatase particles were deposited on glass fibre, the concentration of Ti^3＋ was increased and the concentration of hydroxyl was decreased on the surface of photocatalysts which were doped 0.2% Fe^3＋ and Ce^3＋. Ti^3＋ could adsorb oxygen and react with oxygen to produce Ti^4＋ and O2^- simultaneously on the surface of photocatalysts. Oxidant O2^- plays an important role in the photocatalytic degradation process of benzene.