Functionalization of partially reduced graphene oxide by metal complex as electrode material in supercapacitor

Abstract

High electrical conductivity and high surface area are two main parameters which influence supercapacitor electrode performance. Graphene has gained prominence in electrode of electrical double-layer capacitor due to its high electrical conductivity and high specific surface area. Functionalization of partially reduced graphene oxide is the state-of-the-art method in synthesis of graphene system which is used in electrode of electrical double-layer capacitors (EDLCs). In this study, graphene system was functionalized by 2,6-diaminopyridine cobalt complex with a simple method in available and engineered porous surface area to eliminate agglomeration of graphene sheets and enhance electrical conductivity of them which is suitable for EDLCs. Curved and porous structure that obtained high and available surface area for supercapacitor electrodes was approved by structural analysis such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy and Brunauer–Emmett–Teller. Furthermore, the X-ray photoelectron spectroscopy and Fourier-transform infrared were used for elemental analysis. Also, galvanostatic charge/discharge (GCD), cyclic voltammetry and electrochemical impedance spectroscopy were applied to specify electrochemical behavior of the prepared electrode. Accordingly, the electrical resistance was obtained 5.23 Ω. The specific capacitance was obtained 192 F/g by cyclic voltammetry and 107 F/g by GCD methods.