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

Abstract 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 (NiSe 2 , Ni 3 Se 4 ) and zirconium selenide (ZrSe 3 ) 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‐IrO 2 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.