Highly Efficient Hydrogen Evolution in Alkaline Medium by Ternary Cobalt Molybdenum Nitride on Self-standing Porous Copper Foam

•Self-supporting ternary cobalt-molybdenum nitride was successfully synthesized.•In alkaline medium, CoN/Mo2N/Cu catalyst outperformed the Pt/C benchmark .•The catalyst exhibits exceptional activity and stability. Hydrogen is an ideal energy carrier, owning to high energy density and zero pollution emission. Hydrogen generation in an alkaline environment is desirable but challenging. A few electrocatalysts have been reported for alkaline hydrogen evolution reaction (HER), but are generally suffered from large over potentials and short durability. Herein, we constructed a self-standing ternary cobalt molybdenum nitride catalyst on copper foam using a simple hydrothermal method and treated under a H2 atmosphere subsequently. Remarkably, the CoN/Mo2N/Cu catalyst exhibits ultralow overpotentials of only 18 mV and 68 mV at current densities of 10 mA cm−2 and 100 mA cm−2 for HER in 1.0 M KOH, respectively. In addition, the ternary catalyst achieves superior durability for more than 100 h at the current density of 20 mA cm−2 without evident deterioration, indicating that the catalyst has an encouraging industrial perspective.