Metal organic framework derived CoFe@N-doped carbon/reduced graphene sheets for enhanced oxygen evolution reaction

Abstract

Herein, a sandwich-like hybrid that comprises a cobalt–iron alloy core coated with porous N-doped carbon shells (CoFe@NC) anchored on wrinkled reduced graphene oxide (rGO) sheets is synthesized by the one-step in situ pyrolysis of a metal organic framework. The optimized sandwich-like CoFe@NC/rGO achieves superior OER activity, requires a low overpotential of 278 mV to drive 10 mA cm⁻² and maintains a robust durability. The excellent OER performance is ascribed to the 3D sandwich-like architecture, strongly anchored alloy and N-doped carbon shell, and abundant mesopores, which can enable fast electron transfer, ion diffusion, and O₂ release.