Preparation and Photocatalytic Application of the Composites PMo12/AgNPs Based on Polyoxometalates

Abstract

Supported catalysts, consisting of PMo12 immobilized on silver nanomaterials at different recombination time and the silver nanomaterials with different template sodium citrate amount characterized by FT-IR, XRD, SEM, UV-vis and other test methods. The results show that the AgNPs are relatively uniformed with sizes between 100–300 nm when the sodium citrate addition amount is 9.0 mL. As the reaction time of PMo12/AgNPs increases, the adhesion of AgNPs on the surface of PMo12 becomes more complete. Using PMo12 and PMo12/AgNPs composite materials as catalysts, methylene blue (MB) is photocatalytically degraded under simulated visible light conditions. The results show that PMo12 can catalyze MB effectively, and the decolorization rate reached 98.6% when the catalyst content is 2 g/L, the solution pH is 3 and the MB concentration is 5 mg/L. Under the same experimental conditions, photocatalytic performance of the PMo12/AgNPs system is better than that of the PMo12 further improved the photocatalytic degradation effect of the MB solution with a decolorization rate of 100%. The composite still keeps good photocatalytic activity and stability after three cycles of use. Finally, the catalytic mechanism of the POMs composite material is preliminarily discussed.