Oxygen Vacancy-Enhanced Ni₃N-CeO₂/NF Nanoparticle Catalysts for Efficient and Stable Electrolytic Water Splitting

Highly efficient and cost-effective electrocatalysts are of critical significance in the domain of water electrolysis. In this study, a Ni₃N-CeO₂/NF heterostructure is synthesized through a facile hydrothermal technique followed by a subsequent nitridation process. This catalyst is endowed with an abundance of oxygen vacancies, thereby conferring a richer array of active sites. Therefore, the catalyst demonstrates a markedly low overpotential of 350 mV for the Oxygen Evolution Reaction (OER) at 50 mA cm^-2 and a low overpotential of 42 mV for the Hydrogen Evolution Reaction (HER) at 10 mA cm^-2. Serving as a dual-function electrode, this electrocatalyst is employed in overall water splitting in alkaline environments, demonstrating impressive efficiency at a cell voltage of 1.52 V of 10 mA cm^-2. The in situ Raman spectroscopic analysis demonstrates that cerium dioxide (CeO₂) facilitates the rapid reconfiguration of oxygen vacancy-enriched nickel oxyhydroxide (NiOOH), thereby enhancing the OER performance. This investigation elucidates the catalytic role of CeO₂ in augmenting the OER efficiency of nickel nitride (Ni₃N) for water electrolysis, offering valuable insights for the design of high-performance bifunctional catalysts tailored for water splitting applications.