Herbal residue-derived N, P co-doped porous hollow carbon spheres as high-performance electrocatalysts for oxygen reduction reaction under both alkaline and acidic conditions

Development of carbon-based oxygen reduction reaction (ORR) catalysts with performance superior to noble metals across a wide pH range has been a formidable challenge. Herein, porous hollow carbon spheres co-doped with N, P (NH3-NPCS-900) is directly synthesized from the herbal residues of Lasiosphaera seu Calvatia (LSC). Critically, the N content was significantly enhanced in the presence of ammonia (NH3) and formed a hierarchical porous structure and a large specific surface area (984.7 m2 g-1). With the synergistic effect of these contributions, the NH3-NPCS-900 catalyst exhibit excellent ORR catalytic activity across acidic (E1/2 = 0.615 V) and alkaline solutions (E1/2 = 0.862 V). Zn-air batteries with NH3-NPCS-900 exhibit high peak power density (188 mW cm-2) and better cycle durability (>180 h), showing its potential and promise in applications. This study provides valuable direction and insight into how to develop porous carbon with highly efficient ORR catalytic activity from biomass.

Automated summary

The study synthesized a porous hollow carbon catalyst with high-efficiency ORR catalytic activity, exhibiting excellent performance under both acidic and alkaline conditions. The catalyst showed promising performance in zinc-air batteries, indicating its significant potential for practical applications.