Synthesis of graphene oxide–Ag2CO3 composites with improved photoactivity and anti-photocorrosion

Abstract

Graphene oxide–Ag₂CO₃ (GO–Ag₂CO₃) composites have been prepared by a simple and effective precipitation method, and found to exhibit a higher photocatalytic activity toward degradation of organic dyes, including rhodamine B, methylene blue and methyl orange, in aqueous solution, than pure Ag₂CO₃ crystal under visible light. The Ag₂CO₃ crystal with 0.9 wt% GO content exhibited the highest photodegradation efficiency for organic dyes, which was 2 times that of pure Ag₂CO₃ crystal. The improved photocatalytic activity of GO–Ag₂CO₃ composites was attributed to the corporative effects of high-surface-area of GO sheets, enhanced absorption of organic dyes, small band gap, more efficient separation of photogenerated electron–hole pairs, and good electron acceptor properties of GO. The photocorrosion of Ag₂CO₃ crystal can be efficiently inhibited by GO, since the transfer of photogenerated electrons from the surface of Ag₂CO₃ crystal to GO sheets can reduce the possibility of decomposing Ag⁺ to Ag⁰, which resulted in an improved stability and recyclability of the GO–Ag₂CO₃ composite in the photocatalytic reaction. This facile and straightforward method has promising applications in the fabrication of different graphene oxide-based heterostructure photocatalysts.