Enhanced electro-peroxone degradation of fluoroquinolones using quinone-enriched carbon cathodes via kinetic suppression of O-O bond cleavage.

The electro-peroxone (EP) process is a promising advanced water treatment technology that couples in situ H2O2 electrosynthesis with ozone activation. However, its efficiency is severely limited by low two-electron oxygen reduction reaction (2e--ORR) selectivity and poor three-phase mass transfer. Here, we address these bottlenecks by integrating a quinone-enriched carbon cathode with tailored interfacial microenvironment into a flow-through EP reactor. The quinone functionalities kinetically suppress O-O bond cleavage instead of merely tuning *OOH adsorption, thus steering ORR toward selective H2O2 production. Meanwhile, these groups facilitate rapid H2O2 desorption, achieving a high yield of 96.6 mmol g-1 h-1. The optimized EP system enables fast kinetics and highly efficient degradation of multiple fluoroquinolone antibiotics (3.86 min-1), far outperforming standalone ozonation and electrolysis. Mechanistic investigations confirm that the boosted ·OH flux from the peroxone reaction drives deep oxidation of ozone-resistant intermediates. The system exhibits excellent matrix adaptability and reusability, and enables effective antibiotic removal, antibacterial activity reduction, and multidrug resistance gene mitigation in real aquaculture wastewater. This work demonstrates that interfacial microenvironment engineering provides a reliable and scalable strategy for boosting EP performance toward sustainable antibiotic pollution control.