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

Abstract

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 beta-NiOOH atomic sheets (vertical-beta-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 beta-Ni oxyhydroxide (beta-NiOOH) atomic sheets, facilitating the creation of highly active Ni4+ species. These Ni4+ rich beta-NiOOH sheets enable exceptional oxygen evolution performance in anion exchange membrane water electrolyzers. image