Abstract: Porous Ag-ZnO catalyst was synthesized by calcining the mixed metal oxalate precursor and subsequent exposure in air. The photocatalytic activity under ultraviolet light was evaluated by photocatalytic degradation of methyl orange.The reaction mechanism was also studied. The experimental results show that the photocatalytic activity was influenced by the calcination temperature, calcination period and the heating-up rate. The slower heating-up rate and the longer calcination period were favor of the improvement of photocatalytic activity, while the photocatalytic activity decreases with the higher calcination temperature. The difference of photocatalytic activity for the complex catalysts with exposed period was related to the variation of Ag phase in air. The optimum catalyst was obtained by calcining the precursor doped 4% Ag at 450 ℃ for 6 h at the heating-up rate of 5 ℃/min and subsequent exposure treatment for 6 d in air.

Key words: zinc oxide%photocatalysis%degradation rate%activation