V/Cu/Co-mediated oxide/carbonate heterostructural nanoflowers for high-efficient electrocatalytic overall water splitting in alkaline media

Alkaline water electrolysis is a promising route to high-performance water splitting. However, the rational development of electrocatalysts remains an ongoing challenge in industrial applications. In this work, a novel electrocatalyst, the copper and vanadium codoped cobalt carbonate nanoflowers were loaded on nickel foam (VCuCoCOx@NF) through a facile hydrothermal approach for the first time, which was a high-performance and low-cost bifunctional electrocatalyst toward alkaline water splitting. When the composite material serves as bifunctional catalyst, the current densities achieve 10/100 mA cm-2 at voltages of 1.57/1.62 V in 1.0 mol L-1 KOH electrolyte, so it is superior to the Pt/C-Ir/C@NF (1.59/ 1.72 V). The morphology and structure were characterized by field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM). Density functional theory (DFT) calculation shows that the Gibbs energy changes of the reaction intermediates are decreased due to the codoping of Cu and V. This work not only provides the strategic guidance for large-scale clean energy-related application, but also inspires a novel concept to guide the extending design of transition-metallic mediated electrocatalysts.