Core/Shell NiFe Nanoalloy with a Discrete N‐doped Graphitic Carbon Cover for Enhanced Water Oxidation.

Abstract: Developing highly efficient and earth‐abundant electrocatalysts for the oxygen evolution reaction (OER) is critical in overall water splitting technology. Among all transition‐metal‐based materials, NiFe‐based electrocatalysts have been regarded as the most promising substitute to commercial noble metals in alkaline conditions. To overcome their leaching problem and improve intrinsic stability without compromising activity, we report a NiFe alloy covered with a discrete N‐doped graphitic shell for the OER. The alloy core@discrete graphitic shell structure exhibits enhanced OER activity and stability with a low onset potential of 1.48 V, reduced overpotential of 320 mV@10 mA cm⁻¹, and small Tafel slope value of 41 mV dec⁻¹, which is superior to Ir/C. It is believed that the nitrogen doping, a discrete graphitic shell, and a mesoporous structure work in harmony to enhance the OER performance. [ABSTRACT FROM AUTHOR]