Electrospun sandwich-structured Fe3O4-CeO2/CNTs-Fe3O4-loaded carbon nanofiber mat as a binder-free adsorption-enhanced electro-Fenton cathode for amoxicillin removal.

The extensive use of antibiotic compounds has raised significant ecological concerns and potential threats to public health. In this study, a sandwich-structured Fe3O4-CeO2/CNTs-Fe3O4-loaded carbon nanofiber mat was successfully fabricated through facile electrospinning coupled with subsequent thermal annealing, serving as an innovative three-dimensional adsorption-enhanced electro-Fenton cathode for the removal of amoxicillin (AMX) - a prevalent semi-synthetic β-lactam antibiotic. The results demonstrated that as-prepared electrode exhibited rapid AMX adsorption kinetics, attaining a maximum adsorption capacity of 229.9 mg g-1. Remarkably, over 99% removal of AMX was achieved via a two-stage process: 20-min pre-adsorption followed by 60-min electro-Fenton oxidation. The developed electrode showed exceptional pH adaptability and operational durability, with low metal leaching observed across six consecutive reuse cycles. Mechanistic analysis revealed that the improvement of removal performance originated from synergistic interactions between adsorption of low-level AMX and enhanced degradation of hydroxyl radical (∙OH) electro-generated via as-prepared cathode. This study provides new insights into a binder-free "self-cleaning" electro-Fenton cathode for the removal of antibiotics wastewater.