超声协同光催化还原法制备Ag/TiO_2光催化剂及其活性研究

Preparation of Ag/TiO_2 Photocatalyst by Ultrasonic Assisted Photocatalytic Reduction Method and Study on Its Activity

在光催化还原反应体系中引入超声场制备了Ag/TiO2光催化剂。考察了超声频率、功率等对还原反应的影响,对所制得的负载型Ag/TiO2光催化剂进行微观性能表征,并以低浓度苯酚溶液为降解对象进行光催化氧化活性表征。结果表明,超声场的引入对光催化还原反应有很好的强化作用,促进光催化还原反应的最佳超声频率为45 kHz,同时,Ag+还原率随着超声功率的增加而增大。所制得的Ag/TiO2光催化剂具有粒径小、光催化活性高的特点。

The ultrasonic field was installed in a reactor of photocatalytic reduction reaction to improve the reaction rate, and the Ag/TiO2 photoeatalyst was prepared. Effects of the ultrasonic power and frequency on the photocatalytic reduction process were studied. And the XRD pattern and photocatalytie activity of Ag/TiO2 photocatalyst to lower concentration phenol solution were studied, respectively. The result showed that higher ultrasonic power had stronger promotion capability to reduce Ag＋ than lower ultrasonic power, and Ag＋ reduction rate had the maximum value under the optimized ultrasonic frequency of 45 kHz. The pattern of Ag^＋ indicated that the silver particles scattered as Ag element on TiO2 surface with photocatalytic-ultrasonic reactor was more uniform than that with photocatalytic reactor. The data showed that the photocatalytic activity of prepared Ag/TiO2 photocatalyst was greater than that of TiO2 photocatalyst.