La~（3＋）/Ce~（4＋）掺杂对TiO_2光催化活性的影响

以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备纯的及掺杂稀土的TiO2,重点考察了退火温度对纳米颗粒晶相转变的影响。通过光催化降解实验,探讨了退火温度、退火时间、稀土离子掺杂浓度等因素对TiO2光催化活性的影响。结果表明,TiO2粉末在400℃下为锐钛矿型,具有很高的光催化活性;掺杂的TiO2纳米样品在短时间内降解均较未掺杂TiO2纳米样品的催化活性高;掺La3＋最佳摩尔分数为0.05,掺Ce4＋最佳摩尔分数为0.20,最佳退火温度为400℃,退火时间为9 h。掺La3＋量相对较少时催化活性高,而掺Ce4＋的纳米粉体在相对较高的浓度下可达到完全降解。

Influence of La3+ and Ce4+ on the Photocatalytic Activity of TiO2

TiO2 nanopowders doped with La3＋ or Ce4＋ can be prepared by sol-gel method using tetrabutyl titanate as precursor to inspect the annealing temperature on the crystal structure of TiO2.The photocatalytic degradation experiments are done for TiO2 photocatalytic activity on the different burning temperature,calcined time,and La3＋ or Ce4＋doped concentration.The results show that,TiO2 powder at 400 ℃ is anatase with a high-activity;the doped TiO2 samples show higher photocatalytic activity than the undoped ones in short time;and the best moore score of La3＋doping concentration is 0.05,Ce4＋ doping concentration is 0.20,and the best calcined temperature is 400 ℃,calcined time is 9 h.The former shows higher photocatalytic activity at low doping concentration while the latter achieves complete degradation at relative high concentration.