Engineering Amorphous CoNiRuOx Nanoparticles Grown on Nickel Foam for Boosted Electrocatalytic Hydrogen Evolution

Designing efficient and cost-effective electrocatalysts is crucial for the large-scale development of sustainable hydrogen energy. Amorphous catalysts hold great promise for application due to their structural flexibility and high exposure of active sites. We report a novel method for the in situ growth of amorphous CoNiRuOx nanoparticle structures (CoNiRuOx/NF) on a nickel foam substrate. In 1 m KOH, CoNiRuOx/NF achieves a current density of 10 mA/cm2 with a hydrogen evolution reaction (HER) overpotential of only 43 mV and remains stable for over 100 h at a current density of 100 mA/cm2. An alkaline electrolyzer assembled with CoNiRuOx/NF as the cathode delivers a current density 2.97 times higher than that of an IrO2||Pt/C electrode pair at the potential of 2 V and exhibits excellent long-term durability exceeding 100 h. Experimental results reveal that the combined replacement and corrosion reactions facilitate the formation of the amorphous CoNiRuOx structure. This work provides valuable insights for developing efficient and scalable amorphous catalysts.