Mo‐Doped Cu/Co Hybrid Oxide Nanoarrays: An Enhanced Electrocatalytic Performance for the Hydrogen Evolution Reaction

Abstract To achieve a cost‐effective and performance‐enhanced electrocatalyst for the hydrogen evolution reaction (HER), Mo‐doped Cu/Co hybrid oxides were prepared through the processes of hydrothermal chemistry and dehydration/reduction. Hybrid structures consisting of a polycrystalline hybrid crystal structure and an amorphous structure, and hybrid constituents including at least Cu, Cu 2 O, CuO, CoO, CuCoO 2 , and Cu 2 CoO 3 were identified and characterized by using SEM, HR‐TEM, XPS as well as electrochemical analysis. Interestingly, no information of the doped Mo appeared in the XRD patterns. The reasonable deduction is that Mo might be confined in the amorphous area. The highly developed interface, enhanced conductivity, larger active surface area, abundant oxygen vacancies, and redistribution of electrons among these elements resulted in the significantly enhanced electrocatalytic activity. The optimized Mo‐doped hybrid Cu/Co oxide exhibited catalytic activity with an overpotential of 88 mV to obtain a current density of 10 mA cm −2 in alkaline electrolyte with scarce loss of the initial catalyst activity for 28 h and over 5000 cycles. This work may provide a channel to enhance the performance in the HER.