溶剂热法制备纳米二氧化钛及光催化活性研究

Preparation and Photocatalytic Properties of TiO_2 by Solvothermal Synthesis

以钛酸四丁酯为钛源,氨水为溶剂,氢氟酸为氟源,利用溶剂热法制备二氧化钛粉体。利用X射线衍射(XRD)、扫描电镜(SEM)、氮气吸附脱附(BET)、傅里叶变换红外光谱(FT-IR)等技术对其进行了系统的表征,以亚甲基蓝(MB)溶液为染料,考察了氟离子修饰的TiO_2对光催化性能的影响。结果表明:用氨水为溶剂,氢氟酸为氟源制得的样品TiO_2均为锐钛矿相,氟离子以化学吸附态存在于TiO_2表面,并且氟离子的修饰增加了其晶化度,抑制了晶粒的生长,增大了晶粒的比表面积,促进了羟基自由基(·OH)的形成,从而提高了TiO_2粉体的光催化活性。

F-doped TiO2 has been prepared using tetrabutyl titanate, ammonia and hydrofluoric acid by a solvothermal method. The obtained powders were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, N2 adsorption-desorption isotherms （BET） and Fourier transform infrared （FT-IR）. The photodegradation of methylene blue （MB） solution was used to evaluate the photocatalytic activity of the catalyst under UV light irradiation. The results show that the TiO2 is of the pure anatase phase, and the fluorine atoms are mainly distributed on the surface of TiO2. The photocatalytic activity is increased by adding hydrofluoric acid, since it can increase the surface area, improve the crystallinity of the anatase phase and enhance the formation of free OH radicals.