摘要
利用酸催化的sol-gel法制备了纯TiO2和Pr3+(1.25%)掺杂TiO2纳米粉体,采用XRD、BET、XPS、DRS和SPS等技术对其进行了表征,以亚甲基蓝(MB)的光催化降解为探针反应,评价了其光活性,探讨了Pr3+掺杂对TiO2纳米粉体的光活性的影响机制.研究表明:与纯TiO2相比,TiO2/Pr2O3纳米粒子的光活性显著提高;掺杂Pr3+可以强烈抑制TiO2由锐钛矿向金红石的相变,阻碍晶粒生长,提高高温组织稳定性,改善粉体的表面织构特性,增加粉体的表面羟基和吸附氧含量;Pr3+掺杂能促进光生e-/h+的分离,提高光生e-/h+的氧化还原能力,改善样品表面的吸光性能.由于产生了量子尺寸效应,复合粉体的紫外吸收带边蓝移.
Pure TiO2 and 1.25wt% Pr^3＋ -doped TiO2 composite nano-particles were prepped by an acid-cam- lyzed sol-gel method and characterized by the techniques such as XRD, BET, XPS, DRS and SPS. The photo degradation of methylene blue in aqueous solution was used as a probe reaction to evaluate their photo activity. The mechanism of effects of Pr^3＋ -doping on the photo activity of TiO2 nano-particles was also discussed. The results show that the photo activity of TiO2/Pr203 composite nano-particles is much higher than that of pure TiO2. The presence of Pr^3＋ can inhibit the phase transformation from anatase to rutile, suppress the growth of the crystal grains, raise the specific surface area, improve the high temperature stabilization of pores in the composite nano-powders, increase the contents of hydroxyl groups and adsorbed oxygen on the particle sur- face. The analytical results of SPS confirm that Pr^3＋ -doping can promote the separation of the photo-produced electrons and holes, and enhance their redox power, and improve the light adsorption properties of the particle surface. All the factors above-mentioned can commonly result in the enhancement of the photo activity. For the composite nanoparticles, a quantum size effect appears, resulting in a blue shift of the absorption edge.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2007年第5期619-623,共5页
Materials Science and Technology
作者简介
姜洪泉（1970-），男，博士，教授E-mail：h．q．jianglll9@163．com
王鹏（1957-），男，教授，博士生导师．
