Morphology-Modulated Mesoporous CuO Electrodes for Efficient Interfacial Contact in Nonenzymatic Glucose Sensors and High-Performance Supercapacitors

Abstract

Surface texture of a nanostructured electrode plays a key role in electrochemical application. Here we reported the CuO microspheres with different nanostructures covered nickel foam skeleton obtained via controllable synthesis strategy with the assistance of urea, and their performance in nonenzymatic glucose sensor and supercapacitor applications. The suitable nanostructures are conductive to pave the way to provide sufficient interfacial contact between electrode and electrolyte. The twin CuO microspheres composed of ultrathin nanoslices being ∼6 nm in thickness and presented well-defined mesoporous nanostructure. The glucose sensor based on the twin CuO nanoslice sphere/Ni foam composite electrode had two wide linear response ranges with ultrahigh sensitivity of 1.864×104 μA mM−1 cm−2 from 1 μM to 100 μM and 160.6 μA mM−1 cm−2 from 1 mM to 8 mM, and a remarkable lower detection limit less than 60 nM (S/N = 3), with a response time as fast as 3 s. Besides, we demonstrated that the electrode was capable of delivering superior areal specific capacitance of 425 mF cm−2 at current density of 0.5 mA cm−2 with excellent cycling stability. Moreover, the investigation of the effects of CuO surface morphology on the interfacial processes can be extended to a wide range of electrochemical systems.