Enhancing hydrogen evolution reaction by synergistically coupling NiMo alloy with Mo on Ni foam

The large-scale preparation of non-precious-metal hydrogen evolution reaction (HER) electrodes with remarkable performance was important to the energy crisis. Here, Mo-NiMo/NF (Ni Foam) electrodes were fabricated by homemade high power impulse magnetron sputtering technique with subsequent annealing. The synthesized Mo-NiMo/NF electrodes presented an exceptional electrocatalytic performance with η10 = 71 mV and prominent stability in alkaline aqueous electrolyte for the HER. The experimental data were corroborated by density functional theory (DFT) calculations. The significant catalytic performance for HER active arose from NiMo alloy and the coupling effect between Mo and NiMo alloy. The lowest value on Gibbs free energy of NiMo was -0.027 eV, very close to the ideal value zero. The adsorption energy of hydrogen atom from heterojunction between Mo and NiMo was -1.786 eV, which could facilitate Volmer step to further enhance HER activity. More importantly, this synthesis method reported here was scalable, which could provide a valuable strategy to engineer the electrocatalysts with the aim to improve their catalytic activities. • The Mo/NiMo/NF was successfully fabricated through HiPIMS along with vacuum annealing. • The prepared Mo/NiMo/NF cathode exhibited an excellent HER catalytic activity. • DFT calculations showed synergetic effect of NiMo and heterojunction enhanced of HER performance.