NixFeyN@C microsheet arrays on Ni foam as an efficient and durable electrocatalyst for electrolytic splitting of alkaline seawater

A self-supported nickel-iron nitride microsheet arrays coated with carbon is grown on commercial Ni foam (NixFeyN@C/NF) and used as electrocatalyst for splitting of seawater. The porous architecture and superhydrophilic/superaerophobic surface ensure sufficient exposure of active sites and mass transfer. The synergetic coupling effect between the coating carbon and NixFeyN facilitates the electron transport. The optimal anode (Ni3FeN@C/NF) and cathode (Ni3N@C/NF) electrocatalysts are employed to assemble a two-electrode seawater electrolyzer for overall alkaline seawater electrolysis, which delivers a large current density of 500 mA cm−2 at a low cell voltage of 1.91 V. The superior corrosion-resistance and electron conductivity of the electrocatalyst are responsible for its excellent durability up to 100 hours. This result suggests that the transition-metal nitrides coated with carbon is an effective route to fabricate high-performance and durable hybrid electrocatalyst for hydrogen production from seawater electrolysis.