Nickel Nanoplates Enclosed by (111) Facets as Durable Oxygen Evolution Catalysts in Anion Exchange Membrane Water Electrolyzers

The long‐term stability of Ni‐based catalysts, employed in the anode of anion exchange membrane water electrolyzers (AEMWE), has been a persisting concern. In this work, through a simple and powerful electrochemical anodization process, vertically aligned β‐NiOOH atomic sheets (vertical‐β‐NiOOH) grown on Fe‐doped Ni nanoplates (FeNi nanoplates) as a solution are offered. This innovative electrocatalyst demonstrates sustained stability of constant current density for over 120 d during the oxygen evolution reaction.The zero‐gap AEMWE cell harnessing the anodized FeNi nanoplates achieves a remarkable current density of 2.26 A cm−2 at 1.80 V with an energetic efficiency of 85.1%. It is anticipated that the electrochemically produced highly active, stable Ni‐based nanostructures demonstrate the potential in pushing the boundaries of AEMWE technology. This study presents anodized FeNi nanoplates with vertically aligned β‐Ni oxyhydroxide (β‐NiOOH) atomic sheets, facilitating the creation of highly active Ni4+ species. These Ni4+ rich β‐NiOOH sheets enable exceptional oxygen evolution performance in anion exchange membrane water electrolyzers.