Study on the effect and mechanism of the coupling between microwave and photocatalysis

The TiO2 and SO42-/TiO2 catalysts were prepared by sol-gel method and charaterized by X-ray diffraction, N-2 absorption analysis applying BET method, and microwave absorption spectrum. Photocatalytic oxidation Of C2H4 in air stream was studied. The results(see Fig. 1) showed that the photocatalytic activity of both SO24-/TiO2 and TiO2 catalysts was obviously increased under the reaction condition of ultraviolet(UV) combined with microwave(MW). The time resolved UV-Vis absorption spectrum substantiated that absorptivity of UV of catalysts was effectively enhanced in the presence of microwave field(see Fig. 2). The improvement on photocatalytic activity was attributed to the polarization effect of the highly defected catalysts in microwave field, which increased the transition probability of photon-generated electrons and decreased the electron-hole recombination on semiconductor surface.