Seamlessly Conductive 3D Nanoarchitecture of Core–Shell Ni‐Co Nanowire Network for Highly Efficient Oxygen Evolution

Electrochemical splitting of water is an attractive way to produce hydrogen fuel as a clean and renewable energy source. However, a major challenge is to accelerate the sluggish kinetics of the anodic half‐cell reaction where oxygen evolution reaction (OER) takes place. Here, a seamlessly conductive 3D architecture is reported with a carbon‐shelled Ni‐Co nanowire network as a highly efficient OER electrocatalyst. Highly porous and granular Ni‐Co nanowires are first grown on a carbon fiber woven fabric utilizing a cost‐effective hydrothermal method and then conductive carbon shell is coated on the Ni‐Co nanowires via glucose carbonization and annealing processes. The conductive carbon layer surrounding the nanowires is introduced to provide a continuous pathway for facile electron transport throughout the whole of the integrated 3D catalyst. This 3D hierarchical structure provides several synergistic effects and beneficial functions including a large number of active sites, easy accessibility of water, fast electron transport, rapid release of oxygen gas, enhanced electrochemical durability, and stronger structural integrity, resulting in a remarkable OER activity that delivers an overpotential of 302 mV with a Tafel slope of 43.6 mV dec −1 at a current density of 10 mA cm −2 in an alkaline medium electrolyte (1 m KOH).