Using NH4VO3 and AgNO3 as starting materials, Ag3VO4 powders were synthesized by liquid-phase direct precipitation method. The phases, morphologies, specific surface area and optical properties of the samples were characterized by means of XRD, SEM, BET and UV-Vis techniques. The visible light was used as light source to investigate the photocatalytic activity of Ag3VO4 for the degradation of rhodamine B solution. The results show that the as-prepared samples were monoclinic phase Ag3VO4 when pH values of the reaction mixtures are adjusted to 7. It was also demonstrated that the compositions of the samples are importantly influenced by pH value of the reaction mixture, and the particle size and morphology of the silver vanadate were largely influenced by reaction time, reaction temperature and different surfactants. UV-Vis result indicates that Ag3VO4 has a strong and wide absorption at the wavelength region of 450-800nm, and its energy band gap was 1. 90eV. The photocatalytic degradation results indicate that as-prepared samples have a high visible-light photocatalytic activity. The sample obtained at 80℃ for 8h could decolorize rhodamine B solution well, and the degradation rate of rhodamine B was up to 97. 7% after illuminating for 100min under 35W xenon lamp.%以NH4VO3和AgNO3为原料,采用液相直接沉淀法制备了Ag3VO4粉体,用XRD、SEM、BET和UV-Vis等手段对样品的物相、形貌、比表面积和光学特性进行了表征；以可见光为光源、罗丹明B为目标降解物考察了Ag3VO4的光催化活性.结果表明,反应混合物的pH值对样品的成分有重要的影响,在调节反应混合物的pH值为7时,所制备的样品为单斜相的Ag3VO4；反应时间、反应温度和表面活性剂等对Ag3VO4的尺寸和形貌有较大的影响.UV-Vis分析表明,所得样品在400～680nm有强而宽的吸收,其能带间隙Eg为1.90eV；光催化性能测试表明,样品的可见光光催化活性较高,在35W氙灯照射下,经100min降解,80℃反应8h所得样品对罗丹明B的降解率可达97.7％.
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