▎ 摘　　要

A direct method of producing graphene from graphite oxide (GO) via ultra-sonication is presented in this work. The synthesis of graphene was validated through IR, XRD, Raman, and XPS analyses. Moreover, the diffraction pattern obtained from TEM also validated the formation of graphene with characteristics (002) plane. The electrochemical behavior of GO and graphene was evaluated by electrochemical impedance spectroscopy and linear sweep voltammetry in 0.5M KOH solution. The relatively larger effective pseudocapacitance and broad current peak exhibited by GO in the LSV plots was related with the dominant adsorption of 'H-ads' during reduction of water. It has been considered that large over potential and relatively higher current response exhibited by GO compared to graphene was associated with the preferential adsorption of H-ads in the presence of surface functional groups. (C) 2017 Elsevier B.V. All rights reserved.