Vacuum-assisted synthesis of graphene from thermal exfoliation and reduction of graphite oxide

Abstract

We report a vacuum-assisted method for thermal exfoliation and in situreduction of graphite oxide in large quantity at a temperature as low as 135 °C. The resulting graphene sheets contain only few-layered sheets with an average thickness of 0.9 nm, and their specific surface area (758 m² g⁻¹) is comparable to that of conventional graphene generated at 1050 °C at atmospheric pressure (700 m² g⁻¹). The in situ thermal reduction during the exfoliation process was confirmed by the increased C/O atomic ratio compared to that of graphite oxide. The restoration of the graphitic sp² network makes it highly efficient in improving the electrical conductivity of polymers at a low graphene loading.