O/N co-doped CNT-PTFE composite cathode for neutral H₂O₂ electrosynthesis and stable electro-Fenton degradation of dye

To address the challenges of low selectivity and poor stability in hydrogen peroxide (H 2 O 2 ) electrosynthesis within neutral media, this study developed an O/N co -doped carbon nanotube-polytetrafluoroethylene composite cathode (designated as GF/ONCNTs-6/PTFE). Through precise control of the synergistic effects between pyrrolic-N doping (40.7 %) and carboxyl/ether functional groups, the adsorption of *OOH intermediates was significantly enhanced; simultaneously, PTFE micro-cracks were employed to establish triple-phase interfaces for facilitated oxygen diffusion. The cathode achieved a high H₂O₂ yield of 139.45 mg/L under neutral conditions (pH 7), with a current efficiency of 67.06 %, and exhibited only 8.2 % activity loss after 10 cycles. In an integrated electro-Fenton system, it accomplished 98.8 % degradation of methyl orange within 2 h under optimal conditions. This work demonstrates that defect engineering and O/N functionalization in composite cathodes significantly boost 2e − ORR efficiency, offering a promising laboratory-scale platform for electrochemical wastewater purification