NiCo/Ni/CuO nanosheets/nanowires on copper foam as an efficient and durable electrocatalyst for oxygen evolution reaction

Electrochemical water splitting for hydrogen production is a promising solution for the production of renewable and environmentally friendly energy sources, but it is hindered by the sluggish kinetic process of oxygen evolution reaction (OER). Here, a novel hierarchical core-shell nanoarray NiCo/Ni/CuO/CF was synthesized by assembling Ni–Co hydroxide nanosheets directly on the metallic nickel coated CuO nanowires , as a highly efficient electrocatalyst for alkaline OER. This NiCo/Ni/CuO/CF anode exhibited low overpotentials of 246 mV and 286 mV at current densities of 10 mA cm −2 and 100 mA cm −2 , respectively, and a small Tafel slope of 37.9 mV dec −1 . Moreover, NiCo/Ni/CuO/CF showed robust durability at least 60 h at a current density of 100 mA cm −2 . Detailed investigations verified that the unique nanosheets/nanowires architecture with high conductivity metallic nickel layer can expand the exposure of active sites and accelerate the transport of electrons.