超声水解法制备的纳米二氧化钛光催化性能的研究

Photocatalytic Activity of TiO_2 Prepared by Ultrasonic Hydrolytic Methods

锐钛矿型纳米二氧化钛因其优良的光催化性能在环境保护中得到广泛应用.以TiCl4为钛源,水解过程中施加超声辐照,室温条件下制得了5～6nm锐钛型TiO2.考察了施加超声、煅烧温度及粒径尺寸对甲酸降解率的影响.结果表明,催化剂制备过程中施加超声影响对催化剂的光催化性能影响显著:甲酸的降解率由68.57%提高到97.13%.用超声水解法制备的纳米二氧化钛能够在较宽的煅烧温度范围里(450～650℃)保持较高的光催化活性.随粒径的减小催化剂活性提高,当粒径小于20nm时,显示量子尺寸效应.

Nanosized anatase TiO_2 has been widely used in the field of environmental protection because of its excellent performance in photocatalysis. In this paper, anatase TiO_2 with particle size ranging from 5 nm to 6 nm were abtained at room temperature by the hydrolysis of TiCl_4 under the irradiation of ultrasonication. The effect of ultrasonication, calcinations temperature and particle size on the photocatalytic activity was investigated. The results show that inflicting the ultrasonic irradation upon the preparing process markedly affects the catalyst, i.e., the degradation rate of formic acid are raised from 68.57% to 97.13% and this excellent performance can be found among a wide range of calcinations temperature. With the decrement of particle size, the photocatalytic activity increases, and the quantum size effect was found when the size of TiO_2 was less than 20 nm.