热喷涂法制备的La^(3+)掺杂纳米TiO_2粉末的表征

Characterization of La^(3+) doped TiO_2 prepared by plasma spraying

采用等离子热喷涂法以钛酸四丁酯为主要原料制备出稀土离子掺杂的纳米TiO2光催化剂。通过XRD,XPS,TEM,UV-Vis等检测手段对样品进行表征,同时检测了其光催化性能,并分析了掺杂对TiO2的影响机理。结果表明,所制备的La3+掺杂纳米TiO2是锐钛矿相和金红石相混晶结构,粒径分布在10~50nm之间;La3+掺杂能够促进锐钛矿向金红石的转变,同时抑制TiO2晶粒的长大;La3+掺杂使TiO2紫外-可见吸收光谱发生红移;适量La3+掺杂能显著提高TiO2的光催化活性,最佳掺杂浓度为0.5%(与Ti原子摩尔比),甲基橙降解率在90min内可达到82.4%,比纯TiO2高出13.2%。

TiO_2 nanopowders doped by the lanthanum trivalent ion were prepared by plasma thermal spray with solution of titanium tetra-tert-butoxide. And TiO_2 were characterized by XRD, XPS TEM and UV-Vis. The photocatalytic activities were also investigated. The results showed that the prepared doped powders are the mixture structure of anatase and rutile. La^(3+) doping can promote the transformation of TiO_2 from anatase to rutile, at the same time, it can restrain TiO_2 particle growing up. La^(3+) doping greatly increases the photocatalytic activity of TiO_2, the optimal doping concentration was 0.5%, and the degradation rate of methyl orange is 82.4%, which is 13.2% higher than that with pure TiO_2.