Hierarchical core-shell CuxO@CoMoO4/CF nanoarrays as an efficient electrocatalyst for overall water splitting in alkaline media

Abstract

Bifunctional electrocatalysts with high activity and durability are important in practical electrocatalytic monolithic water decomposition. In this paper, a novel multilayer core-shell CuxO@CoMoO4/CF nanoarray structure catalyst was designed and synthesized by using heterostructure and morphology control strategies. As a core layer, the nanoarray structure of CuxO can provide a larger specific surface area for the subsequent growth of CoMoO4 nanosheets. This structure enables more active sites to be exposed, and then enhances the catalytic activity. Furthermore, the interfacial interaction between CuxO and CoMoO4 enhances the charge transfer rate, which accelerates the reaction kinetics. Therefore, the catalyst exhibited excellent OER and HER catalytic activities under alkaline conditions. The overpotential of oxygen evolution reaction is 257 and 295 mV at 50 and 100 mA cm−2, respectively, and the overpotential for the HER is only 88 mV at 10 mA cm−2. As a bifunctional catalyst, only 1.556 V can drive the total decomposition water of 10 mA cm−2, and the catalytic performance is far superior to that of the single-component catalyst. This work presents a novel idea and method for synthesizing a highly efficient and stable bifunctional electrocatalyst with multilayer heterostructures for integral water cracking.