溶胶-凝胶法制备Ce3+掺杂TiO2的研究

摘要

Using tetra butyl titanate as staring material, nano-TiO2doped with Ce3+was prepared by sol-gel method and the photocatalytic activity under ultra-violet light was evaluated by photocatalytic degradation of methyl blue. The microstructure and properties were analyzed by TG-DTA, XRD, FE-SEM, TEM, and UV-Vis. The results show that doping nano-TiO2with Ce3+causes the red-shift (54 nm) of the optical absorption edge, and the increase of its UV-Vis light absorption; when heated at 550 °C and doped with Ce3+to the ratio of n(Ce3+) : n(TiO2)= 0.05%, the Ce3+-doped TiO2keeps anatase as the main phase and the particle size is 24.9 nm. The degradation rate of methyl blue after four hours of reaction is 85.15%. Rutile appears with the increase of the heat treatment temperature, and the degradation rate of Ce3+-doped sample is increased to 85.52%. So Ce3+-doped TiO2has better photocatalytic properties than the undoped TiO2.%以钛酸丁酯为主要原料,采用溶胶-凝胶法制备了Ce3+掺杂的TiO2纳米粉体,并以亚甲基蓝溶液为目标降解物,研究了掺杂TiO2纳米粉体在紫外光作用下的光吸收和光催化性能.通过TG-DTA、XRD、FE-SEM、TEM、UV-Vis吸收谱等测试手段对样品的结构与性能进行了表征,分析了Ce3+掺杂对TiO2纳米粉体吸收光谱的影响.结果表明,Ce3+掺杂使得TiO2纳米粉体对紫外-可见光的吸收增大,TiO2纳米粉体吸收带发生红移,与纯TiO2相比,红移了54 nm左右;当处理温度为550 ℃,掺杂体系为n(Ce3+):n(TiO2) = 0.05%时,样品结晶完整,主晶相为锐钛矿型,粒径约为24.9 nm,反应4 h降解率达85.15%;随着热处理温度上升,金红石相的出现,同等条件下n(Ce3+):n(TiO2) = 0.05%的光催化降解率也增大,最高达85.52%,优于同等条件下制备的未掺杂的纯TiO2粉体.