Rapid iron redox cycling for nanoplastic and antibiotic electro-Fenton remediation by FeCo alloy on cellulose-derived carbon

Aquatic pollution caused by nanoplastics and antibiotics poses severe threats to ecosystems and human health, demanding efficient remediation technologies. Although the electro-Fenton method shows great potential, traditional iron-based catalysts suffer from sluggish Fe/Fe cycling, poor conductivity, and pH sensitivity. Herein we address these limitations by integrating cobalt (as a second metal) and biomass-derived carbon from carboxymethyl cellulose into Fe-based metal organic frameworks (Fe-MOFs), forming FeCoMOF@CMC via low-temperature calcination. Bimetallic components generate FeCo alloy, which enhances electron mobility through d-orbital hybridization, while biomass-derived carbon transforms into graphitized carbon, which improves conductivity and prevents metal aggregation. This synergistic design accelerates redox cycling of Fe/Fe and Co/Co, boosting ·OH/ClO· production, making the activity of FeCoMOF@CMC much better than using just Fe-MOFs. 100 % nanoplastic and antibiotic remediation can be achieved in Cl-containing systems, with total organic carbon removal >50 %, good reusability and good adaptation to different antibiotics and different aquatic environments. Combined with free radical quenching experiments and Py-GCMS analysis, the potential degradation pathway of the more recalcitrant nanoplastic was elucidated. This work proposes a novel strategy by leveraging FeCo alloy and carbon support to significantly enhance electro-Fenton efficiency of Fe-MOFs materials for advanced water treatment.