Nickel-nitride composite: An eco-friendly and efficient alternative to platinum for electrocatalytic hydrogen production

Water electrolysis using the hydrogen evolution reaction (HER) is a promising method for sustainable hydrogen production. Platinum-based catalysts have traditionally been the most efficient HER catalysts, but their scarcity and sluggish water dissociation limit their practical applications. Here we report on a novel superhydrophilic catalyst of nickel supported on nickel molybdenum nitride (Ni/Ni0.8Mo4.2N6) that outperforms platinum-based nanomaterials. Despite the low catalytic activity of Ni or Ni0.8Mo4.2N6 alone, their optimized composite exhibits exceptional HER activity, with respective 500% and 150% increases in the exchange current and turnover frequency compared to commercial Pt/C. Density of states calculations reveal a decrease in electron density of the supported nickel in Ni/Ni0.8Mo4.2N6, leading to a lower free energy of the HER. These findings demonstrate a powerful electron-engineering strategy for designing supported electrocatalysts with outstanding performance for the HER and related processes. [Display omitted] •A metal nitride catalyst with excellent HER activity (20 mV @ 10 mA cm-2) and high stability (≥ 1000 h) was prepared.•The Ni/Ni0.8Mo4.2N6 was accurately resolved using neutron diffraction techniques for crystal structure determination.•The catalyst showed 500 % higher exchange current density and 150 % higher turnover frequency than commercial Pt/C.•This study offers a potent effective strategy for electronic engineering in developing outstanding HER catalysts.