((1. 中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083；2. 長沙理工大學(xué) 化學(xué)與環(huán)境工程學(xué)院，長沙 410077))
摘 要: 用鈦酸丁酯低溫水解方法合成不同摻雜Nb5+濃度的金紅石型TiO2(r-TiO2)光催化劑，采用XRD、PL、DRS和BET等技術(shù)進(jìn)行了催化劑表征。在光源為高壓汞燈和氙燈、Fe3+為電子受體、懸浮液的pH值為2.0的條件下，考察Nb5+的摻雜量對r-TiO2粒子的光催化分解水析氧活性的影響，并探討了摻雜催化劑的DRS，PL光譜與光催化活性的關(guān)系。結(jié)果表明：Nb5+的摻雜量在0.5%~3.0%范圍時，Nb5+摻雜沒有引起r-TiO2的晶型改變，表面形成氧空位，在導(dǎo)帶底附近形成施主能級，有利于光生電子和空穴的分離，摻雜催化劑光催化活性增強(qiáng)；摻雜催化劑光致發(fā)光強(qiáng)度與其光催化析氧活性的變化趨勢一致，Nb5+摻雜量在1.0%(摩爾分?jǐn)?shù))時，PL光譜強(qiáng)度最大，光催化析氧活性最高，紫外光源和可見光源析氧速率分別達(dá)480 μmol/(L∙h)和78 μmol/(L∙h)；Fe3+的初始濃度為8.0 mmol/L時，催化劑析氧活性最高。
關(guān)鍵字: 摻雜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
