Direct electrodeposition of Ni‐Co‐S on carbon paper as an efficient cathode for anion exchange membrane water electrolysers

The development of an efficient water electrolyser is essential for sustainable hydrogen production; however, its application remains limited by the insufficient performance of the electrode. Herein, we report a rapid, simple, and cost-effective fabrication of an Ni-Co-S cathode for the hydrogen evolution reaction (HER), which is directly usable for an anion exchange membrane water electrolyser (AEMWE). The Ni-Co-S electrocatalysts are prepared on a carbon paper (CP) substrate by a one-step electrodeposition method by controlling deposition parameters such as the deposition potential, time, and electrolyte composition. The optimized Ni-Co-S/CP electrode demonstrates a high HER activity with an overpotential of 91 mV at −10 mA/cm2 in 1.0 M KOH. An AEMWE single cell employing the Ni-Co-S/CP cathode coupled with a commercial IrO2/CP anode exhibits a current density of 1.7 A/cm2 at 2.4 Vcell, which is higher than that of an AEMWE single cell with a commercial Pt/C/CP cathode; this is attributable to the enhancement of the electron and reactant/product transfer via appropriate cathode design.