Hierarchical core-shell Cu(OH)2@CoS/CF nanoarrays for electrocatalytic water oxidation

The oxygen evolution reaction (OER) is accompanied by four-electron transfer, and its slow reaction kinetics seriously hinders the large-scale application of water electrolysis technology. Therefore, there is an urgent need to develop a non-noble metal catalyst with excellent catalytic performance, good stability, and low price. In this study, we utilize interface engineering and morphology engineering strategies to electrodeposit CoS nanosheets on Cu(OH) 2 nanorods to form three-dimensional hierarchical core-shell electrocatalysts, which could not only provide a large electrochemically active surface area and expose more active sites, but also facilitate electrolyte diffusion and gas product release. The catalyst exhibits good electrocatalytic activity with an overpotential of only 321 mV at a current density of 100 mA cm −2 and a stable operation of 40 h at an overpotential of 280 mV. This study provides a simple method for rapidly preparing electrocatalysts with layered core-shell nanoarray structures. • The preparation method is simple and rapid. • Cu(OH) 2 @CoS/CF electrode with core-shell nanoarray structure was prepared. • It offered a current density of 100 mA cm -2 with only an overpotential of 321 mV. • The catalyst worked stably for 40 h at an overpotential of 280 mV.