Nb^5＋掺杂r-TiO2的光催化分解水析氧活性  

Photocatalytic oxidation of water to O_2 over Nb^(5+)-dopant of r-TiO_2

作　　者：吴道新[1] 陈启元[1] 李洁[1] 尹周澜[1] 

机构地区：[1]中南大学化学化工学院

出　　处：《中国有色金属学报》2008年第1期171-176,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家高技术研究发展计划资助项目(2002AA327140)

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480μmol/(L.h)和78μmol/(L.h);Fe3+的初始浓度为8.0 mmol/L时,催化剂析氧活性最高。Photo-catalyst of rutile TiO2 with different Nb^5＋ 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 Fe^3＋ as electron acceptor at pH 2.0 under UV irradiation and visible radiation, the effects of various Nb^5＋ doping concentration on the photocatalytic oxidation activity of Nb^5＋ doped ruffle 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%, Nb^5＋ is doped into ruffle TiO2 lattice without causing any change in ruffle 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 480μmol/（L·h） and 78 μmol/（L·h） under UV irradiation and visible radiation respectively when the Nb^5＋ concentration was 1.0 mol%, which demonstrated certain relationship between photoluminescence performance affected by Nb^5＋ concentration and the photocatalytic activity. The photocatalytic oxidation activity also corresponds to the concentration of Fe^3＋ as electron acceptor, the best initial concentration of Fe^3＋ is 8.0 mmol/L

关 键 词：掺杂Nb^5+ r-TiO2 光催化 析氧 

分 类 号：O643.32[理学—物理化学]