Peroxymonosulfate activation by Cu2O@CuO nanowires array-based electroactive filter for efficient ofloxacin removal

A homemade flow-through electroactive filter was constructed to activate peroxymonosulfate (PMS) for ofloxacin (OFL) fast removal. The Cu2[email protected] nanowires (NWs) electrode was prepared using copper foam as both substrate and Cu source by direct oxidation method. The obtained electrode with abundant surface-active sites and good electrochemical reactivity markedly improved the activation and utilization efficiency of PMS, thus significantly promoting the catalytic removal reactions. The pH, PMS concentration, and applied voltage were optimized for the filter performance. Consequently, the removal efficiency of OFL reached about 80% in a single-pass mode (τ < 5 min). Electron paramagnetic resonance (EPR) and radical scavenging tests confirmed the contribution of diversified active species in OFL removal. The Cu2[email protected] NWs electrode exhibited reliable regenerative properties, which maintained high OFL removal activity after 5 rebuild cycles. Furthermore, the developed electroactive filter exhibited relatively less consumption of energy and PMS dosage compared with the published research. Finally, the underlying mechanism for the outstanding performance of OFL removal was also revealed as well. This work illustrated new light on high-efficient and low-cost remediation strategies for antibiotic wastewater.