In situ Raman Spectroscopy Study of the Formation of Graphene from Urea and Graphite Oxide

Abstract

Graphene, 10 or fewer atomic layers of carbon atoms, has attracted much attention during recent years due to its unique structure and exceptional physical properties. While there exist a wide range of potential applications, as with many nanomaterials, new synthesis techniques are required that allow for a production of graphene on an industrial scale. In this study, in situ Raman spectroscopy was used to study the formation and doping of graphene during urea-assisted thermal exfoliation of graphite oxide (GO), a promising new synthesis method that can be scaled to industrial levels. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mass spectroscopy were used complementary to Raman spectroscopy to assist with the interpretation of the obtained data. Raman spectroscopy is a powerful characterization tool for the analysis of carbon nanomaterials, such as graphene. While several researchers have reported on the reaction of urea and GO, none of the studies found in literature has provided deeper insights on the evolution of the graphene structure and the simultaneous incorporation of nitrogen into the honeycomb lattice during synthesis. The knowledge gained from this work allows for a better understanding of the graphene production process and provides further evidence for the potential nitrogen-doping of graphene via deposition of urea.