Facile One-Step Sonochemical Synthesis and Photocatalytic Properties of Graphene/Ag₃PO₄ Quantum Dots Composites

In this study, a novel graphene/Ag₃PO₄ quantum dot (rGO/Ag₃PO₄ QD) composite was successfully synthesized via a facile one-step photo-ultrasonic-assisted reduction method for the first time. The composites were analyzed by various techniques. According to the obtained results, Ag₃PO₄ QDs with a size of 1-4 nm were uniformly dispersed on rGO nanosheets to form rGO/Ag₃PO₄ QD composites. The photocatalytic activity of rGO/Ag₃PO₄ QD composites was evaluated by the decomposition of methylene blue (MB). Meanwhile, effects of the surfactant dosage and the amount of rGO on the photocatalytic activity were also investigated. It was found that rGO/Ag₃PO₄ QDs (W_rGO:W_composite = 2.3%) composite exhibited better photocatalytic activity and stability with degrading 97.5% of MB within 5 min. The improved photocatalytic activities and stabilities were majorly related to the synergistic effect between Ag₃PO₄ QDs and rGO with high specific surface area, which gave rise to efficient interfacial transfer of photogenerated electrons and holes on both materials. Moreover, possible formation and photocatalytic mechanisms of rGO/Ag₃PO₄ QDs were proposed. The obtained rGO/Ag₃PO₄ QDs photocatalysts would have great potentials in sewage treatment and water splitting.