3D Ni3S2 nanosheet 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 μA 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.