Characterization of structural transformation of graphene oxide to reduced graphene oxide during thermal annealing

Graphene enticed the scientific community for its interesting properties since its discovery. Among different synthesis routes of graphene, reduction of graphene oxide (GO) is mostly preferred because of scalability and advantage of modulation of properties of the end product. Thermal reduction of GO is considered to be the simplest and economic among different reduction techniques. The current work reports an experimental analysis of the structural evolution of GO to reduced graphene oxide (rGO) during thermal treatment. GO has been thermally annealed at an optimized temperature of 350 °C in ambient. Thermal reduction is observed after 7 min of annealing and confirmed by shifting of the first major peak from 12° to 23° in X-ray diffraction pattern. Significant carbon content enrichment and exfoliation are two aspects of the thermal reduction of GO. Carbon content suddenly enriches from 38 wt% in GO to 77 wt%. Exfoliation is confirmed by morphological alterations and decrease in carbon layers from eleven to three.