Efficient Hydrogen Evolution Electrocatalysis at Alkaline pH by Interface Engineering of Ni₂P–CeO₂

It is of significant importance to develop effective non-noble-metal catalysts for hydrogen evolution electrocatalysis under basic conditions. In this study, we demonstrate the facile construction of a Ni₂P-CeO₂ interface based on the central point that low-temperature phosphidation of the NiO-CeO₂ precursor only converts NiO into Ni₂P selectively. The resulting Ni₂P-CeO₂ nanosheet array on Ti mesh behaves as a durable catalyst for alkaline hydrogen evolution reaction (HER) electrocatalysis, and it can reach 20 mA cm^-2 at an overpotential of 84 mV in 1.0 M KOH, outperforming all reported Ni phosphide HER catalysts. Density functional theory calculations reveal that the Ni₂P-CeO₂ interface can promote water dissociation and optimize hydrogen adsorption free energy.