FeNi alloys supported on nitrogen-enriched carbon nanospheres as efficient bifunctional oxygen electrocatalyst for rechargeable Zinc-air battery

The development of high-performance transition metal catalysts to replace precious metal catalysts toward oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) reactions is essential and challenging. Rational embedding of transition metal nanoparticles (NPs) into nitrogen-enriched carbon frameworks to obtain bifunctional catalysts is a well-established approach. Here, we have successfully prepared an integrated electrocatalyst consisting of nitrogen-enriched porous carbon nanospheres and FeNi alloy NPs (P-FeNi/NC) by carbonizing the Hofmann-type FeNi metal–organic frameworks (MOFs) coated with polydopamine (PDA). Benefiting from the abundant ORR-active pyridinic-N species and OER-active FeNi alloy NPs, large surface area, and porous carbon framework, P-FeNi/NC-900 demonstrates a competitive ORR/OER activity (E1/2 = 0.85 V, Ej=10 mA cm-2 = 1.62 V). When applied as the air electrode, the discharging specific capacity normalized to the mass of consumed Zn is 817.2 mAh g−1 at 10 mA cm−2 and the corresponding maximum power density is 164 mW cm−2. Integration of nitrogen-enriched carbon framework and bimetallic alloys provides a new avenue for the rational preparation of bifunctional oxygen electrocatalysis for high-efficiency energy conversion and storage devices.