Efficient solar photocatalyst based on Ag3PO4/graphene nanosheets composite for photocatalytic decolorization of dye pollutants

Abstract

Silver orthophosphate-graphene nanosheets composite (Ag3PO4-GNs) has been fabricated using a facile hydrothermal method. The Ag3PO4-GNs were characterized using XRD, UV–vis DRS and SEM. The photocatalytic activity of Ag3PO4-GNs was evaluated by photocatalytic decolorization of dye aqueous solutions under simulated solar light irradiation. It was observed that Ag3PO4 nanoparticles in Ag3PO4-GNs were attached on the surface of graphene nanosheets.The introduction of graphene nanosheets enhanced remarkably the visible light absorption region of Ag3PO4-GNs compared with bare Ag3PO4. The photocatalytic activity of Ag3PO4-GNs is nearly twice as high as that of the pure Ag3PO4. The removal efficiency can reach more than 90 % by Ag3PO4-GNs under simulated solar light irradiation within 25 min, which might mainly be attributed to high adsorption capacity, extended light absorption range and efficient charge separation. After irradiation for 60 min, 84.70 % TOC mineralization was achieved by Ag3PO4-GNs. Based on the results of detection of active species, the direct oxidization of dye pollutants in aqueous solution by holes takes a major role in the whole decolorization process by Ag3PO4-GNs. As a result, Ag3PO4-GNs with the high photocatalytic activity are proven to be an excellent light photocatalyst for potentially scalable removal of dyes in aqueous solutions and other environmental remediation under simulated solar light irradiation.