Nitrogen-rich hierarchically porous frameworks via benzoxazine ring-opening polymerization for stable oxygen reduction electrocatalysis

The development of efficient, stable, and low-cost bifunctional oxygen electrocatalysts remains a key challenge hindering the commercialization of rechargeable zinc-air batteries (ZABs). This study presents a facile room-temperature polymerization and solvothermal strategy based on benzoxazine ring-opening polymerization to construct an integrated photothermal electrocatalyst (PTBOZ-60-NC-Fe 3 O 4 ) composed of nitrogen-doped carbon aerogel and Fe 3 O 4 nanoparticles. The catalyst features a hierarchically porous structure with a high specific surface area (up to 1702 m 2 g −1 ) and constructs Fe–N/O dual-active sites through interfacial bonding. Under photothermal assistance, it exhibits enhanced bifunctional activity for the oxygen reduction and evolution reactions (ORR/OER), achieving a low potential gap (ΔE) of 0.636 V, which is among the best reported values and surpasses most state-of-the-art catalysts. When applied in a ZAB, it delivers a high power density of 200.5 mW cm −2 and excellent cycling stability, maintaining stable operation for over 2760 cycles even at −30 °C. This work provides a simple and effective material design strategy for high-performance electrocatalysts suitable for demanding environments, particularly for harsh-environment-adaptable energy storage devices.