ZIF-8 modified balsa sawdust-derived nitrogen-doped porous carbon: An efficient cathodic catalyst for boosted H2O2 generation and electro-Fenton removal of tetracycline

A novel nitrogen-doped porous carbon catalyst (NCW) was synthesized via in-situ growth of ZIF-8 on balsa sawdust followed by controlled carbonization. The integration of ZIF-8 significantly increased specific surface area, defect density, and electrochemical activity, while nitrogen incorporation—especially pyridinic and graphitic species—enhanced 2e − oxygen reduction reaction (ORR) selectivity, achieving an exceptional H 2 O 2 selectivity of 94%. When immobilized on a graphite cathode and paired with a boron-doped diamond (BDD) anode, the NCW-based electro-Fenton (EF) system enabled robust in-situ H 2 O 2 generation and efficient tetracycline (TC) degradation. Under optimized conditions, the system achieved a maximum H 2 O 2 accumulation of 0.73 mmol L −1 , completed TC removal within 120 min, and a total organic carbon (TOC) mineralization efficiency of 84.6% after 4 h. Quenching experiments and electron paramagnetic resonance (EPR) spectroscopy identified homogeneous and heterogeneous hydroxyl radicals (·OH) and superoxide radicals ( ‐ O 2 · ‐ ${{\mathrm{O}}_2^{·}}^{‐}$ ) as the key reactive species. The NCW/BDD/EF system demonstrated excellent versatility across various organic pollutants and maintains robust reusability over multiple cycles. This work presents a sustainable strategy for developing wood-derived electro-Fenton catalysts for efficient antibiotic wastewater treatment.