▎ 摘　　要

Graphene was synthesized from graphene oxide (GO) precursor using two distinguished methods, namely, chemical (CRG) and hydrothermal (HRG) reduction. Electrochemical characterizations were performed in three- and two-electrode configurations. In 3-electrode studies, HRG and CRG have shown specific capacitances of 464 and 272 F g(-1), respectively, in 0.5 M H2SO4 solution, whereas in 2-electrode studies, HRG had shown a high specific capacitance of 124 F g(-1) compared to 72 F g(-1) of CRG in 6 M KOH solution. HRG had shown a high energy density of 3.5 Wh kg(-1), at a power density of 3 kW kg(-1). Further, the HRG has retained 81.6% of capacitance during its endurance study of 5000 cycles at 2 A g(-1), whereas CRG had retained 78.1%. The superior performance of HRG may be attributed to the efficient hydrothermal method adopted and resulted in large graphene edges, defects, high surface area, wettability, and low impedance.