In-situ synthesis of visible-light responsive Ag2O/graphene oxide nanocomposites and effect of graphene oxide content on its photocatalytic activity

Ag2O/graphene oxide nanocomposites, as efficient photocatalysts, were prepared by an in situ method using AgNO3 and graphene oxide as reactants under controlled atmosphere. Graphene oxide is synthesised via an eco-friendly method, and the Ag2O nanoparticles displaying elongated spherical morphology are randomly distributed on the surface of GO. The assynthesised nanocomposites were characterised by different characterisation techniques. The results proved that the concentration of graphene oxide in starting solution displayed an important role in photocatalytic performance of Ag2O/graphene oxide nanocomposites. The nanocomposite materials were found to exhibit very improved photocatalytic activity for degrading methylene blue (MB) and Rhodamine B (Rh-B) under visible light irradiation. The photocatalytic activities of the composite were higher than that of P25 (a commercial TiO2 as a benchmark photocatalyst). The significantly improved photocatalytic activity of the nanocomposites could be attributed to the high charge separation and suppressed recombination of photogenerated electron-hole pairs due to GO. The effects of reaction parameters such as pH and the effect of different scavengers on the photocatalytic activity of the composite were studied.