Transitional metal alloyed nanoparticles entrapped into the highly porous N-doped 3D honeycombed carbon: A high-efficiency bifunctional oxygen electrocatalyst for boosting rechargeable Zn-air batteries

Rational development of low-cost, durable and high-performance bifunctional oxygen catalysts is highly crucial for metal-air batteries. Herein, transition metal alloyed FeCo nanoparticles (NPs) embedded into N-doped honeycombed carbon (FeCo@N-HC) was efficiently prepared by a one-step carbonization method in the existence of NH4Cl and citric acid. Benefiting from the honeycomb-like architectures and the synergistic effects of the FeCo alloy with the doped-carbon matrix, the as-synthesized FeCo@N-HC exhibited outstanding oxygen reduction reaction (ORR) with the more positive onset potential (Eonset = 0.98 V vs. RHE) and half-wave potential (E1/2 = 0.85 V vs. RHE), coupled with outstanding oxygen evolution reaction (OER) with the lower overpotential (318 mV) at 10 mA cm-2. Besides, the home-made Zn-air battery has the larger power density of 144 mW cm-2 than Pt/C + RuO2 (80 mW cm-2). This research offers some valuable guidelines for constructing robust oxygen catalysts in clean energy storage and conversion technologies. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Superscript/Subscript Available

Automated summary

Efficiently prepared FeCo@N-HC catalyst exhibited outstanding performance in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), with a more positive onset potential and half-wave potential for ORR, and a lower overpotential for OER. Additionally, it also increased the power density of homemade Zn-air battery compared to commercial catalysts.