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

Yu, Qian; Chen, Yuzhen; Liu, Jiao; Li, Cheng; Hu, Jingguo; Xu, Xiaoyong · Proc Natl Acad Sci U S A · 2024

basic_science · Level V

Where this comes from

Abstract

Nickel-iron oxy/hydroxides (NiFeO<sub>x</sub>H<sub>y</sub>) 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<sub>x</sub>H<sub>y</sub> 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<sub>x</sub>H<sub>y</sub>/MXene, which not only accelerates WOR kinetics but also improves Fe oxidation resistance against segregation. As a result, the NiFeO<sub>x</sub>H<sub>y</sub> 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.