Synergistic coupling Co3Fe7 alloy and CoFe2O4 spinel for highly efficient removal of 2,4-dichlorophenol by activating peroxymonosulfate

Efficient wastewater restoration depends on the robustness and capability of the catalyst to promote sophisticated decontamination technologies. In this study, Co3Fe7–CoFe2O4 nanoparticles (NPs) prepared by facile pyrolysis were completely characterized and used to decompose 2,4-dichlorophenol (2,4-DCP). Furthermore, the catalytic performance and relevant mechanisms involved in the activation of peroxymonosulfate (PMS) were also investigated. The optimal conditions were achieved at the catalyst loading of 0.05 g L−1, PMS dosage of 1.26 g L−1, and pH of 7.7 through the response surface methodology by using the Box–Behnken design model. Under optimal conditions, 97.1% efficiency of 2,4-DCP removal was obtained within 30 min. Moreover, the quenching experiments and electron paramagnetic resonance result indicated that sulfate (SO4•−) and hydroxyl (HO•) radicals were considered as the dominant reactive oxygen species, which resulted in the effective removal of 2,4-DCP in the Co3Fe7-CoFe2O4/PMS system. Moreover, Co3Fe7-CoFe2O4 showed efficient catalytic performance in continuous five runs and exhibited less metal leaching of 0.052 and 0.036 mg L−1 for Co and Fe species, respectively. Furthermore, no considerable change was observed in the structural characteristics of the fresh and used Co3Fe7–CoFe2O4 catalytic system. The above-mentioned results indicated that the synergistic effects between Co3Fe7 alloy and CoFe2O4 spinel not only significantly improved the activity and long-term durability of the catalyst, but also accelerated the Co3+/Co2+ and Fe3+/Fe2+ redox cycles. Overall, the Co3Fe7–CoFe2O4/PMS system provides a novel advanced oxidation approach to further develop multifunctional transition metal-based nanomaterials responsible for producing surface-bound radicals and enhancing the remediation of refractory pollutants in the environmental application.