Co(OH) 2 Nanoparticle‐Encapsulating Conductive Nanowires Array: Room‐Temperature Electrochemical Preparation for High‐Performance Water Oxidation Electrocatalysis

It is highly desired but still remains challenging to design and develop a Co‐based nanoparticle‐encapsulated conductive nanoarray at room temperature for high‐performance water oxidation electrocatalysis. Here, it is reported that room‐temperature anodization of a Co(TCNQ) 2 (TCNQ = tetracyanoquinodimethane) nanowire array on copper foam at alkaline pH leads to in situ electrochemcial oxidation of TCNQ − into water‐insoluable TCNQ nanoarray embedding Co(OH) 2 nanoparticles. Such Co(OH) 2 ‐TCNQ/CF shows superior catalytic activity for water oxidation and demands only a low overpotential of 276 mV to drive a geometrical current density of 25 mA cm −2 in 1.0 m KOH. Notably, it also demonstrates strong long‐term electrochemical durability with its activity being retrained for at least 25 h, a high turnover frequency of 0.97 s −1 at an overpotential of 450 mV and 100% Faradic efficiency. This study provides an exciting new method for the rational design and development of a conductive TCNQ‐based nanoarray as an interesting 3D material for advanced electrochemical applications.