Ag2Mo4O13 photocatalyst was prepared by the hydrothermal method using AgNO3 and (NH4)(2)MoO4 as raw materials in one step. The Ag2Mo4O13 photocatalyst was characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, N-2 adsorption measurements, and terephthalic acid photoluminescence (TA-PL) probing technique. The photocatalytic activity of the photocatalyst was evaluated by photocatalytic oxidation of methyl orange and photocatalytic reduction of nitrobenzene. The results showed that, the optimum catalyst concentration is 3 g/L, and the optimum optical thickness is 49.4. When the reaction solution was illuminated for 60 min and 10 h, and the amount of photocatalyst was 2.0 g/L, the methyl orange conversion and aniline yield were 76.4% and 63.3%, respectively. The effect of different heat treatment conditions on the photocatalytic activity of the photocatalyst was also investigated. The best preparation condition is heat treatment at 500 degrees C for 10 h. Compared with those photocatalysts prepared at any other conditions, the photoabsorption wavelength range of the photocatalyst calcined at 500 degrees C for 10 h extends greatly towards visible light and it also improves the utilization of the total spectrum. The mechanisms of influence on the photocatalytic activity were also discussed. (C) 2010 Elsevier B.V. All rights reserved.