Synthesis and Characterization of Graphene Oxide Based Metallic Sulfides Nanostructures for Supercapacitor Applications

Abstract

The limited available energy sources and their improper use require efficient energy storage devices. Therefore, supercapacitors are more attractive due to light weight, low cost and high specific capacitance. Graphene oxide (GO) based metal sulfides have huge potential for electrochemical applications due to large specific surface area and electrical conductivity. In this study, various GO based metal sulfides were hydrothermally synthesized on nickel foam substrate for supercapacitor applications. The structural phases were observed using X-ray diffraction. The surface morphology of aluminum, strontium, nickel and zinc based sulfides exhibited nanowall, nanorod, nanoplate and nanoweb like structures, respectively. The metal sulfides showed good electrochemical performance, which was depicted using both three and two electrodes systems. The specific capacitance and energy density determined using three electrodes galvanostatic charge discharge for GO based sulfides of aluminum, strontium, nickel and zinc were 2373.51, 1824.14, 2368.833, 2400.30 Fg-1 and 118.68, 91.56, 118.44, 120 WhKg-1, respectively. Similarly, the power densities and specific capacitance retention up to 1000 cycles were measured as 2663.58, 4356.64, 1010.00, 4407.73 WKg-1 and 57, 67, 42.20, 95.90 %, respectively. Furthermore, an excellent two electrodes symmetric behavior was revealed for GO based sulfides of aluminum nanowalls, strontium nanorods, nickel nanoplates and zinc nanoweb, because high energy densities 20.55, 10.55, 15.72, 20.29 WhKg-1 and power densities 585.50, 294.35, 848.50, 485.30 WKg-1, respectively, were observed. Hence, the excellent electrochemical behavior exhibited by the fabricated nanostructures suggested supercapacitor applications.