Formation of Ag3PO4/AgBr composites with Z-scheme configuration by an in situ strategy and their superior photocatalytic activity with excellent anti-photocorrosion performance

Abstract

A novel Ag3PO4/AgBr composite with Z-Scheme structure was constructed and synthesized via a simple in situ ion-exchange strategy on the surface of Ag3PO4 tetrahedra in an alkaline environment. The as-prepared Ag3PO4/AgBr composite has an intimate contact interface and exhibited enhanced visible-light photocatalytic activity, accompanied by superior stability toward degradation of methylene blue (MB) in aqueous solution. Also, a variety of pollutants can be degraded without selectivity, and the degradation efficiency was over 96%. Changes in the bandgap and the detailed degradation mechanism of the Ag3PO4/AgBr composite were analyzed and revealed using characterization analysis, theoretical calculations, and further designed experiments. Sufficient interfacial contact between Ag3PO4 and AgBr was favorable for transferring carriers and lengthening the lifetime of the Z-Scheme system, which simultaneously inhibit photocorrosion and maintain a high degradation rate. The trapping experiments indicate that h+ is a dominant reactive species for the degradation of MB. This Ag3PO4/AgBr photocatalyst with Z-Scheme structure shows great potential for replication and large scale impact on the environmental purification of organic pollutants.