La^(3+)掺杂对纳米TiO_2微观结构及光催化性能的影响

Photocatalytic Activity of Lanthanum DopedNanometer Titanium Dioxide

以钛酸丁酯和氯化镧为原料 ,采用溶胶 -凝胶法制备了La3 +掺杂TiO2 纳米粉体 ,讨论了不同掺杂浓度、不同热处理温度的样品催化降解刚果红染料实验中的光催化活性 ,并通过X射线衍射 (XRD)、透射电镜(TEM)分析了La3 +掺杂TiO2 样品的相组成、晶胞参数和晶粒大小对光催化活性的影响。结果表明 :La3 +掺杂能够显著提高TiO2 粒子的光催化活性 ,最佳掺杂浓度为 10 0∶3 0 ,最佳热处理温度为 6 0 0℃ ;La3 +掺杂的TiO2 的相组成是影响光催化活性的决定性因素 ;晶格膨胀程度及晶粒大小对光催化活性的影响 ,主要是在相组成相同或相近时才体现得比较明显。

The nanometer TiO-2 powders doped with La 3+ were prepared from Ti(OC-4H 9)-4 and LaCl-3 by Sol-Gel processing.The photocatalytic activity of samples at different doping concentration and different heat treatment temperature in photocatalytic degradation of congo red was discussed.The influence of phase composition,cell parameters and crystallite sizes on the photocatalytic activity of La 3+ doped TiO-2 samples were nalyzed by X-ray diffraction(XRD) and transmission electron microscopy(TME) measurement.Results showed that La 3+ doping increased the photocatalytic activity of TiO-2 greatly, the fitting doping concentration was 100∶3.0, the fitting heat treatment temperature was 600℃;phase composition of La 3+ doped TiO-2 was the determinant factor which influenced the photocatalytic activity;the influence of crystal lattice expanding and crystal size were notable only when the phase content was equal or similar.