Reevesite with Ordered Intralayer Atomic Arrangement as an Optimized Nickel‐Iron Oxygen Evolution Electrocatalyst

Abstract Green hydrogen production through electrocatalytic water splitting relies on inexpensive and highly efficient electrocatalysts. Ni−Fe layered double hydroxide (LDH) is considered as one of the most promising non‐precious metal electrocatalysts for the oxygen evolution reaction (OER). Previous research identified the Fe octahedral site surrounded by [NiO 6 ] octahedrons as a highly active and stable site for OER; however, an optimized electrocatalyst material in such a structure is still missing. Herein, reevesite hierarchical nanostructure supported on Ni foam (Reevesite/NF) is constructed to enable the optimal structure toward the OER. Such Reevesite/NF electrocatalysts with a unique ordered intralayer structure are capable of achieving a high current density (300 mA cm −2 ) at a low overpotential of only 283 mV, while the durability of the Reevesite/NF is equally outstanding, offering a promising non‐precious metal OER catalyst toward high‐efficiency water splitting.