Effect of Water Vapor on Microwave-Assisted Photocatalytic Oxidation of Organic Pollutants over Titania
ZHENG Yi, LI Danzhen, FU Xianzhi*(Research Institute of Photocatalysis, Fuzhou University, Fuzhou 350002, China)
It is known that the competitive adsorption of water vapor onto photocatalyst causes a negative effect on gas solid photocatalytic reaction. In this paper, the effect of water vapor on the microwave assisted photocatalytic oxidation of C 2H 4 and C 2HCl 3, with which as model organic pollutants, was examined under different reaction conditions. The results showed that H 2O was an important factor to the photocatalytic oxidation. Because polarization of different substances is quite different in microwave field, the energy of microwave was mostly absorbed by H 2O for the photocatalytic reaction with water vapor. The improvement of C 2H 4 photocatalytic reactivity was attributed to desorption of water vapor from the catalyst surface in microwave field. However, the result of C 2HCl 3 oxidation was opposite, where H 2O was required to complete the reaction.