Hierarchical Porous Carbon Sponge with High Capacitance and High Catalytic Activity for the Oxygen Reduction Reaction

Herein, a unique carbon sponge FeNC@GA-MF with a hierarchical porous structure was prepared by a multi-step self-assembly strategy, with a high surface area of 1184.8 m2 g–1, a pseudocapacitance of 133.5 F g–1, and also superior activity for the oxygen reduction reaction (E 1/2 = 0.866 VRHE). The Zn–air battery fabricated with the FeNC@GA-MF cathode delivers a peak power density of 156 mW cm–2 and a satisfied stability, outperforming the Pt/C cathode, benefiting from the high intrinsic activity and large surface area of the unique hierarchical porous structure. This work provides an effective strategy to fabricate self-supporting electrodes for fuel cells and supercapacitors.