MXene-mediated reconfiguration induces robust nickel–iron catalysts for industrial-grade water oxidation

Abstract

Nickel–iron oxy/hydroxides (NiFeO x H y ) emerge as an attractive type of electrocatalysts for alkaline water oxidation reaction (WOR), but which encounter a huge challenge in stability, especially at industrial-grade large current density due to uncontrollable Fe leakage. Here, we tailor the Fe coordination by a MXene-mediated reconfiguration strategy for the resultant NiFeO x H y catalyst to alleviate Fe leakage and thus reinforce the WOR stability. The introduction of ultrafine MXene with surface dangling bonds in the electrochemical reconfiguration over Ni-Fe Prussian blue analogue induces the covalent hybridization of NiFeO x H y /MXene, which not only accelerates WOR kinetics but also improves Fe oxidation resistance against segregation. As a result, the NiFeO x H y coupled with MXene exhibits an extraordinary durability at ampere-level current density over 1,000 h for alkaline WOR with an ultralow overpotential of only 307 mV. This work provides a broad avenue and mechanistic insights for the development of nickel–iron catalysts toward industrial applications.