▎ 摘　　要

We report a vacuum-assisted method for thermal exfoliation and in situ reduction of graphite oxide in large quantity at a temperature as low as 135 degrees C. The resulting graphene sheets contain only few-layered sheets with an average thickness of 0.9 nm, and their specific surface area (758 m(2) g(-1)) is comparable to that of conventional graphene generated at 1050 degrees C at atmospheric pressure (700 m(2) 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 sp 2 network makes it highly efficient in improving the electrical conductivity of polymers at a low graphene loading.