Fabrication of 1D/2D core–shell Cu NW@NiCo-LDH nanowire arrays as high-performance electrocatalysts for water splitting

Abstract The development of high-performance, cost-effective, and durable bifunctional electrocatalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a significant challenge. In this study, we propose a simple and efficient strategy to fabricate a three-dimensional (3D) hierarchical Cu NW@NiCo-LDH core–shell nanowire array as bifunctional electrocatalyst. In this architecture, copper nanowires (NWs) are fully coated with amorphous NiCo layered double hydroxide (LDH) nanosheets, forming a 1D/2D core–shell structure on Cu foam. This innovative design uniquely combines the excellent conductivity of 1D Cu NWs with the high catalytic activity of 2D NiCo-LDH nanosheets, resulting in synergistic effects that outperform conventional catalyst structures. The resulting architecture offers rapid electron transport, and creates efficient gas diffusion pathways-collectively enhancing catalytic activity for both HER and OER in an alkaline electrolyte. As a bifunctional electrocatalyst, the Cu NW@NiCo-LDH electrode achieves a current density of 10 mA cm −2 with low overpotentials of 119 mV for HER and 233 mV for OER. Moreover, the catalyst demonstrates excellent durability, maintaining performance over 140 h at a high current density of 80 mA cm −2 for OER. Overall, our study introduces a novel 3D Cu NW@NiCo-LDH core–shell nanostructure as an original and scalable solution for bifunctional electrocatalysis in alkaline media, offering strong potential for future green hydrogen production.