Cooperative effects between NiMo alloy enable highly efficient for all-pH-value and alkaline seawater hydrogen evolution

Abstract

Usually, electrocatalysts depend on pH value for Hydrogen Evolution Reaction (HER) limit their practical application. In this study, NiMo alloys were synthesized on Nickel Foam (NF) using electrodeposition. Furthermore, the proportions of the two metallic elements in the electrolyte, current density and deposition time can affect the catalytic performance. Specifically, the optimized Ni0.8Mo0.8/NF shows highly efficient catalytic performances towards HER in acidic, neutral, alkaline, and seawater. At 100 mA·cm−2, the overpotential values are 111, 366, 158, and 163 mV, respectively. In-situ Raman spectroscopy indicates the presence of multiple active sites during the hydrogen evolution process. Moreover, the Density Functional Theory (DFT) reveals the synergistic effect between the two metals optimizes the material structure, reducing the free energy of H2O and H* adsorption on the catalyst surface in acidic and alkaline environments. This work provides deep insights into designing cost-effective and efficient electrocatalysts towards HER in all-pH-value and alkaline seawater.