Construction of CuO/Cu2O@CoO core shell nanowire arrays for high-performance supercapacitors

•The in situ grown CuO/Cu2O substrates by anodic oxidation have low resistance.•The introduction of CoO can enormously enhance the capacitance performance.•Rough surfaces provide sufficient electroactive sites for electrons shuttle.•The shell alleviates strain during electron transfer, improving stability.

In this paper, we reported construction of CuO/Cu2O@CoO core-shell nanowire arrays by combining a chemical deposition method and post-thermal annealing process on Cu foil without any binders and conductive additives. The nanowire arrays were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDX) techniques. The determination results indicate that the nanowire arrays are distinct CuO/Cu2O nanowire core decorated with branched CoO nanosheet shells. In addition, the as-obtained nanowire arrays demonstrate outstanding areal capacitance of 280 mF cm− 2 at a current density of 1 mA cm− 2 as well as superior cycling stability which remains 90.7% of initial capacitance after 3000 cycles. The facile and cost-effective synthesis integrated with the robust electrochemical performances suggests that the CuO/Cu2O@CoO core-shell nanowire arrays are expected to be promising candidate electrodes for high-performance supercapacitor and other energy storage applications.