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

Abstract

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.