Towards low temperature thermal exfoliation of graphite oxide for graphene production

Realizing mass production of graphene materials at low cost and high quality is urgently required for their real applications. Thermal exfoliation of graphite oxide (GO) is considered as a promising strategy though it normally requires a high exfoliation temperature together with a fast heating rate, making the produced graphenes suffer from high cost and concentrated topological defects. A mild exfoliation of GO at a far lower temperature than the predicted minimum temperature, has been demonstrated by introducing a high vacuum to exert an outward drawing force which helps effective exfoliation of the stacked graphene layers. In this contribution, together with a discussion on the foundation of thermal exfoliation and the general principle for low-temperature exfoliation, we review current strategies and indicate possible novel approaches. Low cost and easy operability are highlighted for the low-temperature exfoliation and the resulting graphene materials are characterized by low defect concentration, and unique and tunable surface chemistry to promote potential mass applications in energy-related areas. (c) 2013 Elsevier Ltd. All rights reserved.