Self-supported nickel nitride nanosheets as highly efficient electrocatalysts for hydrogen evolution

Ni3N has been demonstrated as an excellent hydrogen evolution reaction (HER) catalysts that contain active sites with hydrogen adsorption energy. However, the catalytic efficiency of Ni3N is hindered by its inferior electrical conductivity. Herein, we successfully present an effective strategy to boost the H adsorption capability and HER property of Ni3N supported by nickel foam is illustrated. Ni3N nanosheets/nickel foam (Ni3N NSs/NiF) achieve a super low overpotential of 34 mV at 10 mA cm−2 and a fairly small Tafel slope of 54 mV dec−1 in 1 M KOH aqueous solution. Focusing on a self-supported electrode structural design, Ni3N NSs/NiF composites catalysts possess following advantages: (1) abundant exposed edges deriving from thin Ni3N nanosheets; (2) high conductivity of the entire system generating from metallic metal nitrides integrated by metal substrate; (3) synergistic effect between Ni3N and nickel foam, and more effective facets to accelerated reaction kinetics. The developed compound is among the most active electrocatalysts based on non-precious catalysts, which expand and enrich the family of materials suitable as efficient HER catalysts.