Defect-mediated synthesis of AgFe/biochar derived from sago cycas to enhance the activation of peroxydisulfate: Performance and mechanism insight

In this study, a novel composited catalyst (AgFe/biochar) was synthesized using sago cycas as carbon sources by a simple method and then used to activate peroxydisulfate for the degradation of Acid Orange II. The Ag-0 in the AgFe/biochar was formed in the presence of biochar whereas the bimetallic oxide (AgFeO2) was produced in the absence of biochar, which was attributed to the role of defect in biochar. This novel catalyst exhibited remarkably higher catalytic activity, as compared to other catalysts. The scavenging experiments and electron spin resonance results indicated that it coexisted the radical and non-radical species. It is confirmed that Ag+/ Ag-0, Fe3+/Fe2+, defective sites and oxygen-containing groups in biochar were demonstrated to be extremely essential in the activating peroxydisulfate. This work not only offered a feasible approach for the synthesis of novel AgFe/biochar composites but also provided a useful method for the activation of peroxydisulfate to effectively remove organic pollutants in wastewater.