Self-standing 2D/2D CoO@FeOOH nanosheet arrays as promising catalysts for the oxygen evolution reaction.

The rational design of a highly efficient oxygen evolution reaction (OER) is crucial for the practical applications of water electrolysis. Herein, a hybrid CoO@FeOOH/NF electrode was fabricated by loading FeOOH sheets on the surface of CoO nanosheet arrays a newly developed chemical deposition protocol. The decoration of FeOOH on CoO nanosheet arrays not only endows a strong electronic interaction between the two components but also offers sufficient active sites for the OER process. Benefitting from these advantages, CoO@FeOOH/NF exhibited outstanding OER activity in terms of a low overpotential of 209 mV at 10 mA cm and a low Tafel slope of 48.9 mV dec. Moreover, nearly steady state operation current and negligible change in the phase and morphology of the catalyst also indicate remarkable stability. This work may provide an important guide for the design of high-performance electrocatalysts for energy conversion applications.