Three-dimensional graphene@Ni(OH)(2) nanoflake array grown on Ni foam (G/Ni(OH)(2)/NF) as a binder-free electrode of supercapacitor was prepared by combining a one-step hydro thermal approach and Radio frequency (RF) magnetron sputtering technique. Its electrochemical properties were further investigated by the cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectra. The G/Ni(OH)(2)/NF showed high specific capacitance (4.0F/cm(2) at 1.0 mA/cm(2)), good rate charge-discharge capability and long cycling stability (ca. 90.6% of its initial value). This work provides a new method to prepare 3D porous electrode materials based on graphene for application in electrochemical energy storage. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.