N-doped carbon sheets loaded with well-dispersed Ni3Fe nanoparticles as bifunctional oxygen electrode for rechargeable Zn-air battery

The development of highly efficient and bifunctional electrocatalysts is highly desirable for commercializing the rechargeable Zn-air battery. Herein, employing graphitic carbon nitride as carbon precursor, N-doped carbon sheets loaded with Ni3Fe nanoparticles (denoted as Ni3Fe/N-C) have been prepared via a simple pyrolysis strategy. Benefitting from the introduction of triethylene diamine as organic ligand, Ni3Fe nanoparticles with a mean size of 29 nm are dispersed on N-C sheets uniformly. As a result, Ni3Fe/N-C exhibits excellent electrocatalytic activity toward both oxygen reduction and evolution reactions (For oxygen reduction reaction, the half-wave potential of Ni3Fe/N-C is 0.81 V; for oxygen evolution reaction, the overpotential at 10 mA cm(-2) is 310 mV). Finally, when used as air electrode in rechargeable Zn-air battery, a high power density of 128 mW cm(-2) and a long cycling life up to 134 h at 10 mA cm(-2) are achieved. Our study thus provides a promising air electrode material for rechargeable Zn-air batteries. (C) 2019 Elsevier B.V. All rights reserved.