Enhanced Water Oxidation Catalysis of Nickel Oxyhydroxide through the Addition of Vacancies

Enhancing catalytic efficiency for the oxygen evolution reaction (OER) is of extreme importance for the future of sustainable energy. One of the best-performing catalysts reported to date is nickel oxyhydroxide (NiOOH). However, during operating conditions, NiOOH has varying hydrogen content. To understand how hydrogen vacancies affect catalytic efficiency, we use density functional theory + U calculations that model oxygen evolution reaction catalysis for NiOOH with hydrogen vacancies. Our calculations reveal that these defects destabilize the surface by altering local oxidation states and therefore reduce the overpotential. Our results agree with a very recent experiment that shows enhanced OER activity of NiOOH upon deprotonation.