Microwave-Assisted Rapid Exfoliation of Graphite into Graphene by Using Ammonium Bicarbonate as the Intercalation Agent

Making full use of the unique properties of graphene has required a new route for its scalable production. Here we demonstrate a green and fast approach for preparing high-quality few-layer graphene sheets (GS) based on a microwave irradiation method. This method takes advantage of solvent-free microwaves directly and violently exfoliates pristine graphite into GS by using ammonium bicarbonate (NH4HCO3) as a peeling media. In the microwave heating process, the decomposition of NH4HCO3 into H2O steam, CO2, and NH3 can generate strong pressure that exceeds the van der Waals force between the sheet layers of graphite, achieving effective peeling off of the sheets to very large graphene with fewer defects.