Multiphase Nickel Selenide–Zirconium Selenide Encapsulated with Nitrogen‐Doped Carbon for Efficient Hydrogen and Oxygen Generation

In this study, self-supported multiphase nickel selenide and zirconium selenide (NiZrSe) nanoparticles on nitrogen-doped carbon are obtained from a layered double-hydroxide template. The NiZr nanoparticles are catalytically liberated from NiZr-metal-organic frameworks during selenization, forming nickel selenide (NiSe₂, Ni₃Se₄) and zirconium selenide (ZrSe₃) nanoparticles encapsulated in a nitrogen-doped carbon framework on the surface of nickel foam. Benefiting from the synergistic effects of multiphase NiZrSe-nanoparticles, improved conductivity, vertically aligned sheet-like 3D morphology, and large electrochemical surface area, the prepared catalyst demonstrates remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. The optimized electrocatalysts require a low overpotential of 108 mV at a current density of 10 mA cm^-2 for the HER and 210 mV for the OER at 20 mA cm^-2, with robust stability for 100 h in 1 m KOH. In addition, the catalyst exhibits a cell voltage of 1.68 V at 20 mA cm^-2, which is comparable to the device equipped with Pt/C-IrO₂ when applied as an anode and cathode in a two-electrode electrolytic cell. These findings open a new direction for bimetallic selenide catalysts for energy storage and conversion.