原位红外光谱法研究La/TiO_2对有机污染物的光催化降解  

In Situ FTIR Study on Photocatalytic Degradation of Organic Contaminants over La^(3+)-doped TiO_2

作　　者：黄雅丽[1] 李旦振[2] 付贤智[2] 王绪绪[2] 

机构地区：[1]闽江学院化学与化学工程系,福州350108 [2]福州大学光催化研究所,福州350002

出　　处：《无机化学学报》2006年第7期1275-1281,共7页Chinese Journal of Inorganic Chemistry

基　　金：闽江学院科研育苗项目(No.YKY03004)

摘　　要：本工作采用改进的溶胶-凝胶法和浸渍法制备了TiO2掺杂稀土离子La3+的La/TiO2光催化剂,运用XRD、N2吸附脱附、紫外可见漫反射光谱(DRS)、表面光电压谱(SPS)等手段进行表征,同时利用原位红外技术考察了La/TiO2样品光催化降解乙烯、丙酮、苯的气-固相光催化氧化反应,对其光催化降解有机污染物的过程进行了研究。结果表明,TiO2经适量La3+掺杂后,锐钛矿晶型的含量增加,晶粒度减小,比表面积增大,禁带宽度增加,表面光电压信号增强,光生电子-空穴对有效分离;La/TiO2样品对乙烯、丙酮、苯的光催化性能与纯TiO2相比均有不同程度的改善,乙烯可以被光催化氧化完全矿化生成CO2,而丙酮被光催化氧化可能生成中间产物丙酸,苯被光催化氧化可能生成中间产物苯酚和苯醌。The La^3＋-doped TiO2 photocatalyst was prepared by the improved sol-gel and impregnation method. XRD, N2 adsorption, UV-Vis diffuse reflection spectroscopy and surface photovohage spectroscopy （SPS） were applied to study the effect of La^3＋doping. At the same time, the photocatalytic process of TiO2 and La^3＋-doped TiO2 catalysts for degradation of ethylene, acetone, benzene were further studied by means of in situ FTIR. The result indicated that La^3＋ doping could enhance the photocatalytic activities of ethylene, acetone, benzene to some extend as compared with pure TiO2. The increase in photoactivity is probably due to higher content of anatase, smaller particle size , higher specific surface area and lager band gap. In addition, the higher photocatalytic activity of La^3＋-doped TiO2 may be attributed to the stronger photovoltage signal and the effective separation of photo-generated electron-hole pairs. The result also showed that ethylene could be photocatalytically oxidized to CO2. The acetone and benzene may be photocatalytically oxidized to propionic acid and phenol, quinone, respectively.

关 键 词：TIO2 La^3+掺杂 光催化氧化 原位红外光谱 有机污染物 

分 类 号：O613.72[理学—无机化学] O614.411[理学—化学]