Enhancing Hydrogen Evolution Reaction by Synergistically Coupling Nimo Alloy with Mo on Ni Foam

Abstract

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 along with vacuum annealing. The synthesized Mo/NiMo/NF electrodes presented an exceptional electrocatalytic performance and prominent stability in alkaline aqueous electrolyte for the HER. The experimental data were corroborated by density functional theory (DFT) calculations, which was further observed that the significant catalytic performance for HER active arose from the coupling effect between NiMo alloy and Mo, and Ni alloying with Mo. The lowest values on Gibbs free energy of NiMo was 0.067 eV, very close to ideal value zero. And 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.

Keywords: High power impulse magnetron sputtering, Hydrogen evolution reaction, Density functional theory, Synergistic effect, Electrocatalysis