Synthesis of surfactant-free SnS nanorods by a solvothermal route with better electrochemical properties towards supercapacitor applications

Abstract

We demonstrate a simple, low cost, and eco-friendly synthesis of surfactant free tin monosulfide (SnS) nanorods by a solvothermal route for applications in supercapacitor devices with high specific capacitance. The as-synthesized SnS nanorods, consisting of an intrinsic layered structure, were thoroughly characterised by XRD, TEM, HRTEM, SEM, EDAX and BET techniques to determine their crystal structure, size, morphology and surface area. To explore potential applications for supercapacitors, the nanocrystals were used to fabricate a two electrode system without adding any binder, large area support or conductive filler, and the system was characterised by cyclic voltammograms, galvanostatic charge–discharge and electrochemical impedance spectroscopy measurements in aqueous 2 M Na₂SO₄ electrolyte. These SnS nanorods exhibit enhanced supercapacitor performance with specific capacitance, energy density and power density values of ∼70 F g⁻¹, 1.49 W h kg⁻¹ and 248.33 W kg⁻¹, respectively, which are found to be two times higher than those of SnS–carbon composites, and thus make SnS nanorods a better alternative source for energy storage devices.