Synergistic role of nickel-chromium heterogeneous selenides in the efficient stabilisation of the oxygen evolution reaction

Abstract

The oxygen evolution reaction (OER), a kinetically sluggish process, remains critical for water electrolysis in clean energy production. Transition metal selenides (TMSs) have emerged as promising catalysts, owing to their high conductivity, tunable electronic properties, and cost-effectiveness. In this study, nickel-chromium layered selenide nanosheets were synthesized in-situ on a nickel-chromium foam (NCF) substrate using a hydrothermal method. The resulting NiSe₂-Cr₂Se₃/NCF exhibits a large specific surface area, abundant heterogeneous interfaces, and optimized electronic structures, which demonstrate efficient electrocatalytic activity in the OER within a 1 M KOH electrolyte (173 mV at 10 mA cm^-2, 246 mV at 100 mA cm^-2). Density functional theory (DFT) calculations reveal that the heterogeneous chromium-nickel structure modifies the electronic density of active sites, enhancing charge transfer and lowering the energy barrier for the OER. Additionally, the biphasic structure prevents phase degradation and surface passivation during long-term operation, thereby enhancing stability. This work not only demonstrates the potential utility of NiSe₂-Cr₂Se₃ heterostructured selenides in large-scale electrochemical water splitting but also provides novel insights into the design of high-performance transition-metal selenide catalysts featuring multiphase heterostructures.