Nickel-based alloy nanoparticles anchored on nickel mesh towards excellent and sustainable water electrolysis

Mixed metallic alloys have gained significant attention as favorable electrocatalytic materials for water splitting due to their high conductivity and stability. Here, NiCox and NixFe bimetallic alloys with rich pore structures were prepared by electrodeposition on the nickel mesh (NM), which exhibited high electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evaluation reaction (OER), respectively. At the same time, the synergistic effect of bimetal atoms greatly improved the electrochemical performance compared to monometallic electrodes. When the NiCo4/NM electrode performed as a cathode, the current density reached 10 mA cm−2 at an overpotential of 43 mV, which was comparable to that of the precious metal Pt/C. On the other hand, the Ni4Fe/NM electrode showed an overpotential of only 201 mV at 10 mA cm−2 OER current density. In addition, the electrolyzer assembled with Ni4Fe/NM || NiCo4/NM electrodes afforded low cell voltages of 1.50 and 1.76 V at 10 and 100 mA cm−2, respectively, and excellent long-term stability of more than 80 h. This would be a promising study for replacing the precious benchmark electrocatalysts.