LiF掺杂TiO_2的制备及其光催化性能  

Preparation of LiF-Doped TiO_2 and Its Photocatalytic Performance for Degradation of Methylene Blue

作　　者：江宏富[1] 周作兴[1] 刘杏芹[1] 孟广耀[1] 

机构地区：[1]中国科学技术大学材料科学与工程系,安徽合肥230026

出　　处：《催化学报》2007年第4期377-382,共6页

基　　金：国家重点基础研究发展计划(973计划;2003CB615700).

摘　　要：采用溶胶-凝胶法制备了LiF掺杂的TiO2光催化剂,并采用X射线衍射、X射线光电子能谱和光致发光光谱等技术对样品进行了表征.以亚甲基蓝的光催化降解为反应模型,考察了LiF掺杂量、退火温度和溶液pH值对催化剂光催化性能的影响.结果表明,LiF的掺杂降低了金红石相的形成温度,同时在TiO2表面引入大量羟基氧并提高了TiO2表面氧空穴浓度,因此提高了TiO2的光催化性能.在LiF掺杂量为8%,退火温度为500℃和反应液pH值为6.6的条件下,LiF掺杂的TiO2的光催化活性是未掺杂TiO2的6倍.LiF-doped TiO2 catalysts were prepared by the sol-gel method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and photoluminescence. The photocatalyst activity for the degradation of methylene blue was evaluated, and the effects of the LiF doping amount, annealing temperature, and pH value of the reaction liquid were investigated. LiF doping favored the formation of the rutile phase, introduced a large amount of hydroxyl, and increased the oxygen vacancy concentration on the surface of TiO2, which led to the high photocatalytic activity of LiF-doped TiO2. Under the conditions of 8 % LiF doping, annealing temperature of 500 ℃, and reaction liquid pH value of 6.6, the photocatalytic activity of LiF-doped TiO2 was 5 times higher than that of undoped TiO2.

关 键 词：溶胶-凝胶法 二氧化钛 氟化锂 掺杂 亚甲基蓝 光催化降解 

分 类 号：O643.32[理学—物理化学] O644.1[理学—化学]