Interfacial coupling effect of CoO/CoMoO4 promotes alkaline hydrogen electrode for hydrogen energy storage system

Abstract

Herein, CoO and CoMoO4 heterostructure supported on nickel foam (CoO/CoMoO4@NF) are proposed as an effective bifunctional hydrogen evolution reaction (HER) and hydroxide reaction (HOR) electrocatalyst. The electron density distribution at the interface can be optimized by coupling CoO and CoMoO4, thereby improving conductivity and regulating the hydrogen binding energy (HBE) and hydroxyl binding energy (OHBE). CoO/CoMoO4@NF exhibits high stability and activity with an exchange current density of ∼3.67 mA cm−2. Co/CoMoO4@NF reaches the current density of −10 mA cm−2 at only −29 mV and the corresponding Tafel slope of 40.2 mV dec−1. This work provides a promising solution for non-precious metal catalyst for hydrogen reaction in energy storage.