Preparation of reduced graphene oxide macro body and its electrochemical energy storage performance

Abstract

A graphene oxide (GO) solution was obtained by modified Hummers’ method, which was used to prepare GO aerogel by freeze-drying technique. A high quality reduced graphene oxide (HrGO) macro body could be obtained from the GO aerogel by high temperature H2 treatment at 800 ℃. The obtained samples were characterized with Fourier transform infrared spectra, X-ray diffraction, scanning electron microscope, Raman spectra, X-ray photoelectron spectroscope, high resolution transmission electron microscope and nitrogen adsorption-desorption analyser. Moreover, the electrochemical energy storage performance of the sample was tested by assembling into electrochemical supercapacitors. The results show that a GO aerogel with a three-dimensional network structure can be prepared by freeze-drying technique with controlling the concentration of GO solution. There are few oxygen-containing functional groups on the obtained HrGO macro body, which has a few layers and a large specific surface area of 485.3 m2 g−1. The electrochemical discharge capacitance of the macro body is up to 133 F g−1 with a current density of 3.4 A g-1 (organic electrolyte).