低温无模板法制备TiO2多孔球及其光催化性能研究

以钛酸四丁酯为钛源,乙二醇和丙酮为溶剂,以低温无模板法制备纳米TiO2多孔微球。XRD分析可知,随着沸水处理时间的增长,纳米晶粒TiO2多孔微球的晶化程度逐渐提高。沸水处理120 min时得到的锐钛型TiO2已具有较高的晶化程度。TEM和SEM研究表明,经沸水处理后的有机前驱体表面由光滑转变粗糙,多孔结构形成。BET数据分析表明,在其它相同条件下,沸水处理120 min时得到的纳米晶粒TiO2多孔微球具有较高的BET比表面积,且介孔体积较大,表面反应活性位点较多,更有利于对RhB的吸附。光催化结果表明,沸水处理120 min时得到的的TiO2多孔微球具有较好的光催化活性,其一级反应速率常数为沸水处理30 min时得到的纳米晶粒TiO2多孔微球的11.29倍,为P25的1.74倍。这是由于纳米晶粒TiO2多孔微球的介孔结构和较高的比表面积能引入更多的表面反应活性位点所致。

Preparation of TiO2 nanocrystal porous microsphere under low temperature without template method for superior photocatalytic activity

TiO2 porous microsphere were prepared at a low temperature without template method by using tetrabutyl titanate as copper source and both ethylene glycol and acetone as solvents. XRD analysis shows that with the increase of boiling water treatment time, the crystallization degree of TiO2 nanocrystal porous microsphere increased gradually. The anatase TiO2 obtained by boiling water treatment with 120 min had a higher degree of crystallization. The results of TEM and SEM showed that the surface of organic precursor treated with boiling water changed from smooth to rough, and porous structure was formed. The analysis of BET data shows that under the same conditions, TiO2 porous microsphere prepared by boiling water treatment with 120 min had higher BET specific surface area, larger mesoporous volume and more active sites of surface reaction, which was more favorable for the adsorption of substances. The photocatalytic results show that TiO2 porous microsphere treated by boiling water with 120 min had better photocatalytic activity, the kinetic constant was 11.29 folds of that of TiO2 porous microsphere treated by boiling water with 30 min and 1.74 folds of that of P25. This is due to the fact that the mesoporous structure and high specific surface area of TiO2 microspheres could introduce more active sites of surface reaction.