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

Abstract

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 as-synthesised 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.