Heterogeneous activation of peroxymonosulfate for bisphenol A degradation using CoFe2O4 derived by hybrid cobalt-ion hexacyanoferrate nanoparticles

Abstract

A facile coprecipitation-thermal method is reported to prepare spinel cobalt ferrites CoFe2O4 nanoparticles (NPs) with a well-defined mesoporous dominated structure using hybrid cobalt-ion hexacyanoferrate (CoFeHCF) NPs as a template. The properties of the synthesized catalysts are evidenced by various characterization methods. And the effects of time, pH, catalyst/oxidant/BPA dosage, coexisting ions and natural organic matter (NOM) on catalytic degradation of bisphenol A (BPA) are investigated. The as-prepared CoFe2O4 shows a high catalytic performance of 97% elimination for 45 μM BPA in 40 min. The excellent catalytic performance could be attributed to the large specific surface area (66.18 m2/g) and high content of cobalt (the atomic ratio of Fe/Co is 1.86) of CoFe2O4 NPs. Slightly alkaline pH, higher catalyst dosage and anions including Cl− and CO32−/HCO3− are favorable for BPA degradation. Especially, 81.57% mineralization of BPA could be achieved in 60 min under the optimization system. The catalytic capacity of CoFe2O4 could be regenerated by simple washing and drying at 200℃, which is much lower than the crystal temperature. SO4∙− and HO∙ are the primary reactive species responsible for BPA oxidation while SO4∙− might play a dominant role. This work provides a novel method to produce CoFe2O4 nanocatalysts for contaminant degradation and encourage the extended application of CoFeHCF in the environment.