The enhanced mechanism of ZnIn2S4-CoFe2O4-BC activated peroxomonosulfate under visible light for the degradation of fluoroquinolones

• Composite photocatalytic material ZnIn 2 S 4 -CoFe 2 O 4 -BC was synthesized. • Vis/ZnIn 2 S 4 -CoFe 2 O 4 -BC/PMS system exhibits superior catalytic performance for ENR degradation. • Heterojunctions improve the efficiency of utilizing sunlight. • The activation of PMS includes metal and direct electron activation. • Intermediate and possible degradation pathways of ENR were proposed. Visible light is a sustainable method for activation peroxomonosulfate (PMS). In this study, the ZnIn 2 S 4 -CoFe 2 O 4 -BC (ZIS-CFO-BC) composite photocatalytic material was synthesized by two-step hydrothermal and solvothermal methods to enhanced the efficiency of sunlight utilization. The morphology analysis revealed ZIS and CFO particles are uniformly dispersed on the Biochar (BC) surface, forming a stable heterojunction interface. A 96.39 % removal of enrofloxacin (ENR, 2 mg/L) was achieved within a 30 min period by the Vis/ZIS-CFO-BC system. According to the quenching and EPR tests, SO 4 •− , h + , •OH, and 1 O 2 were identified as the primary active species. Valence changes were observed for both Co and Fe, indicating that this is primary site for PMS activation. The findings of the cycling and co-existing ions experiments illustrate that ZIS-CFO-BC exhibits remarkable potential for various applications. This research presents a new recyclable green material that efficiently utilizes sunlight to enhance the Fenton-like system.