Highly electrocatalytic three-dimensional chain-like nickel-based electrocatalysts with hierarchical structures for hydrogen evolution reactions.

In this study, a three-dimensional (3D) electrocatalyst with a hierarchical structure was developed by growing chain-like Ni nanowires (Ni NWs/NF) vertically on a nickel (Ni) foam and then depositing Ni nanoparticles (Ni/Ni NWs/NF) on the surface of nanowires by an electrodeposition process, and the obtained binder-free Ni/Ni NWs/NF electrode exhibited highly electrocatalytic activity and stability for hydrogen evolution reactions (HERs). The results indicate that the conductive substrate, three-dimensional morphology, and synergetic effect between different nickel species result in excellent electrocatalytic performance in HERs. The Ni/Ni NWs/NF electrode can deliver a current density of 10 mA cm at an overpotential of 52 mV for HERs. The strategy developed in this study provides a new and facile way to design and construct 3D transition metal-based electrocatalysts for the electrocatalytic reaction of water splitting.