稀土Ho掺杂TiO2纳米晶的光催化性能研究  

STUDY ON THE PHOTOCATALYTIC ACTIVITY OF RARE EARTH Ho-DOPED TiO_2 NANO-CRYSTALLINE

作　　者：蔡河山[1] 刘国光[2] 黎晓霞[1] 吕文英[2] 余林[2] 

机构地区：[1]佛山科学技术学院资源环境系,广东佛山528000 [2]广东工业大学环境科学与工程学院,广东广州510006

出　　处：《水处理技术》2008年第5期37-39,49,共4页Technology of Water Treatment

基　　金：国家自然科学基金资助(20677012);广东省科技计划项目(2006A36701003)

摘　　要：采用酸催化的溶胶-凝胶法制备出了具有高光催化活性的稀土Ho掺杂TiO2纳米晶光催化剂,以甲基橙的光催化降解为探针反应,从表观降解率和TOC去除率两个指标评价了样品在不同焙烧温度、Ho掺杂量和反应气氛下的光催化活性。结果表明,在光催化降解甲基橙的试验中,500℃焙烧制得的0.5%Ho-TiO2样品表现出最佳的光催化活性,其降解速率比同等条件下制得的纯TiO2提高了3.31倍。光催化反应进行15min后对甲基橙的表观降解率达99.85%,反应进行30min后对甲基橙水溶液TOC的去除率为79.61%,TOC的去除效果滞后于色度的去除。不通空气时,样品对甲基橙的降解率最差,降解速率明显滞后于通空气和氧气的情况且通氧气的降解效果更好。High photocatalytic activity rare earth Ho-doped TiO2 nano-sized photocatalysts were prepared by an acid-catalyzed sol-gel method. The photocatalytic decomposition of methyl orange in aqueous solution was used as a probe reaction to estimate their photocatalytic activities according to two evaluation indices of apparent decomposition rate and TOC removal rate. The photocatalytic activities of TiO2 samples with various Ho dopants calcined at different temperatures and in different reaction atmospheres were investigated. The results showed that the 0.5%Ho-doped TiO2 calcined at 500 ℃ exhibited the highest photocatalytic activity in the experiment ofphotocatalytic decomposition of methyl orange. Its apparent decomposition rate constant was 3.31 times higher than that of the pure TiO2 prepared at the same condition. The apparent decomposition rate of methyl orange on 0.5% Ho-TiO2 calcined at 500 ℃ was up to 99.85% after 15 min, but the TOC removal rate was only 79.61% after 30 min. The TOC removal rate was inferior to the apparent decomposition rate of methyl orange. Moreover, the apparent decomposition rate of methyl orange on Ho-doped TiO2 in O2 reaction atmosphere was optimal.

关 键 词：二氧化钛 钬掺杂 TOC 反应气氛 光催化活性 

分 类 号：TQ034[化学工程]