Fabrication of anchored copper oxide nanoparticles on graphene oxide nanosheets via an electrostatic coprecipitation and its application as supercapacitor

Copper oxide (CuO) nanoparticles have been synthesized through a sonochemical assisted precipitation followed by thermal treatment. As prepared CuO nanoparticles have been anchored on surface of graphene oxide (GO) nanosheets through a simple electrostatic coprecipitation. Prepared samples have been characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray analysis (EDX). Morphology of the samples has been characterized by field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Symmetric supercapacitors have been assembled in real two-electrode configurations. Different symmetric configurations including CuO, GO, layer-by-layer coated CuO on GO network (GO/CuO), and composite (COMP) electrodes have been prepared. Their electrochemical behavior and supercapacitive performances have been investigated and compared with each other using various electrochemical methods including cyclic voltammetry, electrochemical impedance spectroscopy, and chronopotentiometric charge/discharge cycles. The composite material shows better electrochemical supercapacitive behavior and lower charge transfer resistance compared to other samples. It also shows better specific capacitance (245 F g(-1)) at current density of 0.1 A g(-1) compared to the pure components (125 F g(-1) for CuO and 120 F g(-1) for GO) and the layer-by-layer coated electrodes (155 F g(-1)). Conducting charge/discharge measurements for 1000 cycles and in different current densities, it has been found that the composite material is a promising candidate for supercapacitor application, in terms of cycle ability and rate capability. (C) 2012 Elsevier Ltd. All rights reserved.