The synergistic effect of graphene oxide and silver vacancy in Ag3PO4-based photocatalysts for rhodamine B degradation under visible light

Spherical-like Ag3PO4 and graphene oxide (GO) wrapped Ag3PO4 (Ag3PO4@GO) composites with different GO contents were successfully synthesized via facile co-precipitation and ultrasonic processes. The morphologies, structures, and surface bonds of the samples were characterized by SEM, TEM, XRD, FTIR, and XPS spectroscopy. Furthermore, photocatalytic activities toward rhodamine B (RhB) degradation of these samples under visible light were evaluated. The experimental results indicated that the breaking of the weak Ag-O bond led to silver vacancies (V-Ag) in Ag3PO4 lattice, which acted as trapping centers of photo-generated holes. The enhanced photocatalytic performance of the Ag3PO4@GO samples could be explained by the synergistic effect of V-Ag and GO. Ag3PO4 hybrid with 10 mg GO (Ag3PO4@10GO) was turned out to have the highest content of V-Ag, thus leading to the optimum improvement of photocatalytic activity.