Exploring the use of fast electron backscattering for the determination of the C/O ratios: possible applications to graphene oxide and reduced graphene oxide

GO and rGO are carbon nanostructures with a wide range of applications. The carbon/oxygen ratio (C/O) is a basic parameter that determines many of its essential properties. The large-scale production of these materials requires the use of fast and representative methods to determine the C/O ratio. In the present work, the feasibility of using fast electron backscattering to determine this relationship was explored. The method is rapid and does not require previous sample treatment, its accuracy is approximately 11%–15% for C/O ∼ 10–35 and its precision is around 0.4%. It was estimated that the backscattered electrons being detected came from a sample mass of 0.04–0.4 g, depending on the synthesis method used. The accuracy of the backscatter method is approximately equal to that of EDX and XPS, but it surpasses them in precision and representativeness. Backscattering equipments are more economical when compared to the above-mentioned techniques; however, it can be affected by the presence of impurities. Therefore, we consider it an appropriate method for the large-scale control of samples of GO and rGO produced by a given technology and calibrated with a rigorous elemental analysis.