The production of reduced graphene oxide by a low-cost vacuum system for supercapacitors applications

Graphene (G) has attracted great interest for its excellent electrical properties. However, the large-scale production of graphene is still currently under investigations. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups with the recovery of a conjugated structure. It can be produced using inexpensive graphite as raw material by cost-effective chemical methods. High vacuum and temperature (10^-7mbar/1100 deg C) is well established as an effective route for reduced powder preparation on a laboratory scale. However, a high vacuum reduction system, which can be routinely operated at 10^-7 mbar, has a considerable capital, operational and maintenance cost to be used in a large scale. In the present work, a low-cost route aiming large scale reduction of graphene oxide has been investigated. A stainless steel vessel has been evacuated to backing-pump pressure (10^-2 mbar) to process graphene oxide at low and high temperatures. Attempts of reducing GO powder using low vacuum pressures have been carried out and investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental results of processing graphene oxide powder at various temperatures (200-1000°C) at relatively low pressures have been reported. The microstructures of the processed material have been investigated using scanning electron microscopy (SEM) and chemical microanalyses employing energy dispersive X-ray analysis (EDX). (author)