One step synthesis of SnS2-SnO2 nano-heterostructured as an electrode material for supercapacitor applications

SnS2-SnO2 nano-heterostructures are synthesized with two different precursors of thioacetamide (TAA) and thiourea (TU) at various solvent ratios (SR) of ethanol and water by using a facile, economical, scalable, and cost-effective solvothermal method. The obtained products have been characterized by Xray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Brunauer-Emmet-Teller (BET) techniques. It is found that different precursors and various SR values have an influence on the composition and morphologies of the prepared nanostructures, leading to variation in capacitive behavior of the fabricated electrodes. Electrochemical properties of the prepared nanostructures are investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy in a three-electrode system. The obtained SnS2-SnO2 nano-heterostructures from TAA and TU in a SR value of 0.7 deliver a specific capacitance of 149.0 and 71.4 Fg(-1) at an applied current density of 2 Ag-1, respectively. Furthermore, SnS2-SnO2 nano-heterostructures synthesized with TAA and TU in the mentioned value of SR can be successfully applied to assemble a symmetric supercapacitor device. The specific capacitances of 70.2 and 31.5 Fg(-1) are obtained for the SnS2-SnO2 samples prepared using TAA and TU in SR = 0.7, respectively, at a current density of 2 Ag-1 in the two-electrode system. Additionally, symmetrical supercapacitors obtained from SnS2-SnO2 synthesized with TAA and TU exhibit capacitance retention of 92 and 90% after 3000 galvanostatic charge-discharge cycles, respectively. Good electrochemical performances can be attributed to the appropriate composition and porous structure of the SnS2-SnO2 nano-heterostructures. (C) 2018 Elsevier B.V. All rights reserved.