A cabbage leaf like nanostructure of a NiS@ZnS composite on Ni foam with excellent electrochemical performance for supercapacitors

Abstract

In the present study, a NiS@ZnS composite nanostructure was synthesized on a nickel foam substrate by a facile chemical bath deposition (CBD) method. The prepared composites were analyzed by X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and field emission scanning electron microscopy. The electrochemical performance of the supercapacitor (SC) electrodes was examined by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The NiS@ZnS composite exhibited a cabbage leaf like nanostructure and showed outstanding electrochemical performance in SCs with a specific capacitance of 1533.0 F g⁻¹ at a current density of 7.5 A g⁻¹, good cycling stability with 97.9% retention over 3000 cycles, greater energy density, and excellent rate capability compared to the bare NiS (1279.83 F g⁻¹) and ZnS (616.66 F g⁻¹)-based electrodes in SCs. The facile, novel synthesis method, outstanding performance, well defined surface morphology, synergetic effect and low cost make the NiS@ZnS composite an ideal electrode material for electrochemical energy storage devices.