((1. 中南大学 化学化工学院，长沙 410083；2. 长沙理工大学 化学与环境工程学院，长沙 410077))
摘 要: 用钛酸丁酯低温水解方法合成不同掺杂Nb5+浓度的金红石型TiO2(r-TiO2)光催化剂，采用XRD、PL、DRS和BET等技术进行了催化剂表征。在光源为高压汞灯和氙灯、Fe3+为电子受体、悬浮液的pH值为2.0的条件下，考察Nb5+的掺杂量对r-TiO2粒子的光催化分解水析氧活性的影响，并探讨了掺杂催化剂的DRS，PL光谱与光催化活性的关系。结果表明：Nb5+的掺杂量在0.5%~3.0%范围时，Nb5+掺杂没有引起r-TiO2的晶型改变，表面形成氧空位，在导带底附近形成施主能级，有利于光生电子和空穴的分离，掺杂催化剂光催化活性增强；掺杂催化剂光致发光强度与其光催化析氧活性的变化趋势一致，Nb5+掺杂量在1.0%(摩尔分数)时，PL光谱强度最大，光催化析氧活性最高，紫外光源和可见光源析氧速率分别达480 μmol/(L∙h)和78 μmol/(L∙h)；Fe3+的初始浓度为8.0 mmol/L时，催化剂析氧活性最高。
关键字: 掺杂Nb5+；r-TiO2；光催化；析氧
（(1. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;2. Changsha University of Science and Technology, College of Chemistry and Environmental Engineering,Changsha 410076, China)）
Abstract:Photo-catalyst of rutile TiO2 with different Nb5+ doping concentrations were prepared by low temperature hydrolysis using Tetrabutyl titanate(C16H36O4Ti) as raw material. Powders were characterized by XRD, PL, DRS and BET. Using Fe3+ as electron acceptor at pH 2.0 under UV irradiation and visible radiation, the effects of various Nb5+ doping concentration on the photocatalytic oxidation activity of Nb5+ doped rutile TiO2 particles were investigated. The relationships between the DRS, PL spectra with the photaocatalytic activity were also discussed. The results show that with appropriate concentration in 0.5%−3.0%, Nb5+ is doped into rutile TiO2 lattice without causing any change in rutile TiO2 crystal structure. Therefore, surface oxygen vacancies and the donor energy level near the bottom of the conduction band lead to easier separation of photoinduced electrons from holes to achieve stronger photocatalytic activity. The highest photocatalytic oxygen evolution and PL spectra intensity are achieved with the O2 evolution speed of 480 μmol/(L∙h) and 78 μmol/(L∙h) under UV irradiation and visible radiation respectively when the Nb5+ concentration was 1.0 mol%, which demonstrated certain relationship between photoluminescence performance affected by Nb5+ concentration and the photocatalytic activity. The photocatalytic oxidation activity also corresponds to the concentration of Fe3+ as electron acceptor, the best initial concentration of Fe3+ is 8.0 mmol/L
Key words: Nb5+-doped; rutile titania; photocatalytic; O2 evolution
