Synergistic pollutant degradation by Ag3PO4/Fe3O4/graphene oxide visible light–persulfate coupled system: Mechanism elucidation and performance optimization

Abstract

Herein, we investigated the synergistic degradation of p-chlorophenol by a Ag3PO4/Fe3O4/graphene oxide visible light–peroxydisulfate coupled system, probed the effects of catalyst and peroxydisulfate dosage, pH, operating mode, and coexisting substances, identified decomposition intermediates, and proposed plausible degradation pathways. The advantages of the coupled system, namely reduced agent dosage and efficient and thorough degradation, justified the involvement of a precious metal (Ag), while mechanistic investigations suggested the importance of the peroxydisulfate peroxo bond and electron transfer between multivalent metal catalyst components for degradation performance enhancement. Thus, this work facilitates the development of high-efficiency and low-cost combinations of advanced oxidation processes.

Keywords

• Photocatalysis
• Persulfate activation
• Coupled system
• Synergistic mechanism
• P-chlorophenol
• Water remediation