Green synthesis of reduced graphene oxide as high-performance electrode materials for supercapacitors

Abstract

Two kinds of reduced graphene oxide are successfully synthesized by hydrothermal reduction and ascorbic acid reduction and further employed as high-performance electrode material for supercapacitors. These two kinds of reduced graphene oxide exhibit excellent properties as they possess large specific surface and highly reduced state. The structure, morphology, vibrational response, and thermal stability are performed using XRD, SEM, TEM, Raman spectroscopy, and thermo-gravimetric analysis, respectively. While the specific surface area and pore size are carried out via BET surface area technique, the capacitive behaviors of electrode materials are investigated in a three-electrode system at room temperature. The hydrothermal reduced graphene oxide (HT RGO) electrode delivers high specific capacitance of 341 F g−1 at a current density of 1 A g−1 and exhibits excellent cycling stability with 91.58% retention ratio after 5000 cycles, much better than that of ascorbic acid-reduced graphene oxide (AA RGO). This can primarily be ascribed to the larger specific surface area and higher degree of reduction of HT RGO. This work underlines the potential of green approaches to prepare reduced graphene oxide electrode material for high-performance supercapacitors.