超声场中sol-gel法制备纳米TiO2光催化剂的研究

本文在频率分别为20kHz、30kHz、40kHz(电功率均为500W)的超声场中制备溶胶。用光散射法测得溶胶粒子粒径分别为29．4nm、18．3nm、13．2nm，对无超声场和超声场(40kHz)制备的凝胶进行超临界乙醇干燥。用XRD、BET、TEM、DRS对上述干燥的TiO2粒子进行表征，以光催化降解罗丹明B为模型反应。结果表明，在实验范围内溶胶粒径随超声波频率的升高而减小，加超声场制备的纳米TiO2粒子光催化活性比无超声场下制备的粒子高。

Preparation of nanometer titanium dioxide by the sol-gel method in anultrasonic field

Titanium dioxide sol is prepared by the sol-gel method with respectively 20kHz, 30kHz, 40kHz (500W electric power) ultrasonic field. The diameters of the sol particles, detected by light dispersion are 29.4nm, 18.3nm, 13.2nm respectively. The gel obtained in the 40kHz ultrasonic field and in no-ultrasonic field (nature state) is dried by supercritical ethanol. The dried titanium dioxide particles are then charactered by XRD, BET, TEM, DRS. Degradation of rhodamine B by photocatalysis is regarded as model reaction. Experimental result displays that the diameter of the sol particle reduces with the increasing frequency of ultrasound and that the photocatalystic activity of nanosized titanium dioxide particle prepared in ultrasonic field is superior to that of the particle prepared without any ultrasonic field.