Modulating surface properties of Mn-Fe nanocube-like catalyst to activate peroxymonosulfate for effective benzalkonium chloride degradation

The increasing consumption of Benzalkonium chloride (BAC) require more available and efficient processing techniques for environmental protection. Here in, etched MnFe nanocubes (E-MnFe NC) with cubic-like structures were synthesized as peroxymonosulfate (PMS) activator for BAC degradation via etching and calcination treatment of MnFe Prussian blue analogues (MnFe PBA). In this E-MnFe NC/PMS system, more than 99% BAC was degraded with the mineralization efficiency of 59.8% under optimum condition in 60 min. For mechanism, quenching results and EPR analysis demonstrated that both SO4•− and HO• are main contributor in the oxidation process. The transformation of surface charge and hydrophobic properties boosted the BAC adsorption, thus contributing to subsequent oxidation reaction. Meanwhile, the enhancement of electron transfer efficiency dominated by oxygen vacancies promoted the catalytic performance. Finally, the degradation pathway of BAC was proposed based on density functional theory (DFT) analysis and GC–MS results. Meanwhile, E-MnFe NC/PMS system possessed ascendant stability and reusability, as well as certain feasibility in actual environmental application. Overall, this work provides valuable references for quaternary ammonium compounds (QACs) degradation via SR-AOP about Fe-Mn catalyst.