Interface-engineered hollow carbon matrix-supported FeCo alloy as an enhanced magnetic activator for peroxymonosulfate to degrade an endocrine disruptor in water: A comparative study for elucidating advantageous roles of Fe-dopant

Abstract

While transition metals are useful for activating peroxymonosulfate (PMS) to degrade refractory contaminants, bimetallic alloys exhibit stronger catalytic activities owing to several favorable effects. Therefore, although Co is an efficient transition metal for PMS activation, FeCo alloys are even more promising heterogeneous catalysts for PMS activation. Immobilization/embedment of FeCo (FC) alloy nanoparticles (NPs) onto carbon matrices appears as a practical strategy for evenly dispersing FeCo NPs and enhancing catalytic activities via interfacial synergies between FeCo and carbon. Herein, carbon matrix-supported FeCo alloy (CMFC) is fabricated here to exhibit a unique hollow-engineered nanostructure and the composition of FeCo alloy by using Co-ZIF as a precursor after the facile etching and Fe doping. The Fe dopant embeds FeCo alloy NPs into the hollow-structured N-doped carbon matrix, enabling CMFC to possess the higher meso‑porosity, active N species as well as more superior electrochemical properties than its analogue without Fe dopants, carbon matrix-supported cobalt (CMC). Thus, CMFC exhibits a considerably larger activity than CMC and the benchmark catalyst, Co3O4 NP, for PMS activation to degrade bisphenol A (BA). Beside, CMFC+PMS shows an even lower Ea for BA degradation than literatures, and retains its high efficiency for eliminating BA in different water media. CMFC also maintains its composition and activities over multiple degradation cycles. The ecotoxicity assessment unravels that BA degradation by CMFC+PMS did not result in the formation of toxic and highly toxic byproducts during its decomposition process, making CMFC a promising heterogeneous catalyst for PMS activation to degrade BA.