Mechanism and improvement of the visible light photocatalysis of organic pollutants over microcrystalline AgNbO3 prepared by a sol–gel method

Abstract Microcrystalline AgNbO 3 photocatalysts were successfully prepared by a sol–gel method. The photocatalytic activities of the samples were evaluated by the degradation of various organic pollutants under visible light irradiation ( λ ≥ 420 nm). The results indicated that AgNbO 3 was favorable for adsorbing cationic dyes such as rhodamine B and methyl blue, and its photocatalytic performances were dominated by the adsorption abilities for different organic pollutants. For the degradation of rhodamine B, the sample prepared at 650 °C showed the highest photocatalytic activity and good stability due to its suitable surface area and crystallinity. On the basic of the experimental results, photo-induced holes were suggested as the main oxidation species for the pollutants decomposition over AgNbO 3 . Furthermore, the photocatalytic activity of AgNbO 3 was greatly enhanced by the addition of an electron acceptor AgNO 3 . The enhanced photocatalytic mechanism was also discussed.