Unprecedented carbon sub-microspheres with a porous hierarchy for highly efficient oxygen electrochemistry

Developing efficient and robust electrocatalysts for bifunctional oxygen electrocatalysis is crucial for renewable energy technology. Herein, nitrogen and phosphorus co-doped carbon sub-microspheres with fascinating mesostructures are rationally synthesized through an effective soft-templating strategy. The unique features of substantial doping, large surface areas and well-defined porosity endow the dual-doped carbons with high-density electroactive sites, considerable active surface areas and improved mass transfer, ensuring impressive activity and durability in catalyzing oxygen reduction and evolution reactions, even competing with the noble metal benchmarks, thus assuring their use as an air cathode in a rechargeable Zn-air battery with low charge-discharge overpotential and remarkable long-term stability.