3D Ni₃S₂nanosheet arrays supported on Ni foam for high-performance supercapacitor and non-enzymatic glucose detection

Abstract

3D Ni3S2 nanosheet arrays grown on Ni foam were successfully synthesized through a facile one-step hydrothermal approach and then directly applied as the electrode for a high-performance supercapacitor and non-enzymatic glucose sensor. The structure and morphology of the prepared Ni3S2 were characterized by X-ray power diffraction (XRD), field emission scanning electronic microscopy (FESEM) and transmission electron microscopy (TEM). The subsequent electrochemical measurements showed that the Ni3S2 nanosheet array electrode possessed a superior specific capacitance of 1370.4 F g(-1) at a current density of 2 A g(-1). Remarkably, a specific capacitance of 952.0 F g(-1) could be still achieved at a high current density of 20 A g(-1), indicating its excellent rate capability. And 91.4% of the specific capacitance was retained after 1000 cycles at a current density of 6 A g(-1). Besides, to demonstrate its practical application, an asymmetric supercapacitor based on the Ni3S2 nanosheet array electrode as the positive electrode and activated carbon as the negative electrode was assembled. It delivered high energy density and good long-term stability. Additionally, serving as a non-enzymatic sensor, the 3D Ni3S2 nanosheet array electrode exhibited remarkable electrocatalytic activity towards glucose oxidation with a high sensitivity of 6148.0 mu A mM(-1) cm(-2). All these impressive performances suggest that the Ni3S2 nanosheet array is a promising electrode material for supercapacitors and non-enzymatic glucose sensors.