Enhanced catalytic activity of electrodeposited Ni-Cu-P toward oxygen evolution reaction

The slow kinetics of the oxygen evolution reaction (OER) and the high cost of the precious metal catalysts for the OER limit the efficiency and cost-effectiveness of water splitting. In this study, we introduce electrodeposited nickel-copper-phosphorous (NiCuP) as an efficient OER electrocatalyst in alkaline medium. The addition of Cu into the NiP electrocatalyst significantly enhanced the OER activity. Optimization of the electrodeposition conditions revealed that Ni59Cu19P9 in terms of atomic percent exhibited the best activity with a reduced Tafel slope and charge transfer resistance for the OER, compared to NiP. The Ni59Cu19P9 catalyst successfully endured the OER operation at 10 mA/cm2 for up to 30 h while maintaining a Faradaic efficiency of over 99%. The X-ray photoelectron spectroscopy showed that the amount of active Ni hydroxide (NiOOH) species increased with the addition of Cu, which likely contributed to the enhanced of catalytic activity.