摘要
利用XRD ,TEM ,BET和UV Vis等测试技术对商品的ZnO及TiO2 和纳米ZnO及TiO2 粒子进行了表征 .无论是商品的还是纳米的 ,在光催化氧化降解气相n C7H1 6 和SO2 及液相苯酚的反应中 ,TiO2 均表现出比ZnO高的光催化活性 ,并从光腐蚀性和表面电荷两方面分析了其原因 .在光催化氧化降解n C7H1 6 的反应中 ,ZnO粒子易失活 ,而TiO2 粒子不易失活 .但是 ,在光催化氧化降解SO2 的反应中 ,ZnO和TiO2 粒子均易失活 .SPS和XPS测试结果表明 ,光催化剂表面的导电类型由反应前的n型变成了失活后的 p型 .这主要是由于反应产物发生吸附所致 .
The commercial ZnO and TiO_2,and the nanometer ZnO and TiO_2 particles were characterized by XRD, TEM, BET and UV-Vis techniques, and their photocatalytic activity was evaluated. The results showed that the photocatalytic activity of TiO_2 is higher than that of ZnO, for either commercial or nanometer particles, in the process of degradation of gas phase n-C_7H_ 16 and SO_2 or liquid phase phenol. This result was explained by analysing the effects of light corrosion and surface charges of the photocatalysts on their activity in the process of photocatalytic reaction. Moreover,the lifetime of ZnO and TiO_2 with nanometer particles was examined. The result showed that ZnO lost its activity in the oxidative degradation of n-C_7H_ 16, while TiO_2 nearly kept it. Both ZnO and TiO_2 lost their activity in the oxidative degradation of SO_2. The deactivation mechanism was analysed by characterizing the photocatalysts using SPS and XPS methods, indicating that the deactivation possibly results from the change of the surface conduction type of semiconductor from n-type before the reaction to p-type after the deactivation owing to the adsorption of products. In addition, the deactivated photocatalysts can be regenerated to a nearly full degree by washing and drying.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第3期175-180,共6页
