A hierarchical CoP@NiCo-LDH nanoarray as an efficient and flexible catalyst electrode for the alkaline oxygen evolution reaction

The oxygen evolution reaction plays a vital role in lots of reproducible oxygen-based electrochemical technologies; however, suffering from intrinsically sluggish kinetics, it requires acceleration by highly-efficient water oxidation electrocatalysts. Moreover, flexible catalyst electrodes are preferable for practical technological devices. Here, we report the electrochemical deposition of ultrathin NiCo-layered double hydroxide nanosheets on a metallic CoP nanowire array directly grown on carbon cloth. The as-prepared CoP@NiCo-LDH/CC behaved efficiently as a three-dimensional (3D) flexible electrode material for catalyzing the alkaline oxygen evolution reaction. In 1.0 M KOH, affording a 20 mA cm(-2) geometric catalytic current density, 87 and 52 mV overpotential reduction was observed for this CoP@NiCo-LDH/CC compared with its CoP/CC and NiCo-LDH/CC counterparts, respectively. Impressively, it also demonstrated strong durability, with its catalytic activity being maintained for at least 20 h, and a high turnover frequency value of 0.009 O-2 s(-1) at 360 mV overpotential.

Automated summary

This study reports the electrochemical deposition of ultrathin NiCo-layered double hydroxide nanosheets on metallic CoP nanowire arrays directly grown on carbon cloth, demonstrating efficient catalyzing of the alkaline oxygen evolution reaction. The new material shows lower overpotential compared to its counterparts, indicating higher catalytic efficiency and good durability.