Highly active CoFe–carbon nanosphere electrocatalysts with triazine-driven architecture for bifunctional oxygen reactions in zinc–air batteries

Abstract

Designing efficient and durable bifunctional electrocatalysts remains a key challenge for rechargeable zinc–air batteries. Herein, we report a rationally engineered CoFe alloy nanoparticle-modified nitrogen-doped porous carbon nanosphere catalyst (CoFeNHCNF-x), synthesized using a covalent triazine framework (CTF) as both a nitrogen-rich precursor and structural template. The CTF-derived architecture effectively exposes metal nanoparticles and enhances mass transport, while promoting strong metal–support interactions. As a result, CoFeNHCNF-4 exhibits outstanding bifunctional oxygen electrocatalytic performance, delivering an ORR half-wave potential of 0.86 V vs. RHE and an OER overpotential of 290 mV at 10 mA cm⁻². When assembled in a ZAB, the catalyst achieves a high peak power density of 156.4 mW cm⁻², a specific capacity of 711 mAh g⁻¹, and remarkable cycling stability over 500 h at 10 mA cm⁻², outperforming commercial Pt/C + RuO₂ counterparts. This work provides a promising strategy for the development of high-performance bifunctional air electrodes via synergistic integration of CTF-derived carbon supports and transition metal alloys.