Microwave synthesis of large few-layer graphene sheets in aqueous solution of ammonia
Graphene, transmission electron microscopy (TEM), expanded graphite exfoliation, microwaves
Few-layer graphene (FLG) sheets with sizes exceeding several micrometers have been synthesized by exfoliation of expanded graphite in aqueous solution of ammonia under microwave irradiation, with an overall yield approaching 8 wt.%. Transmission electron microscopy (in bright-field and dark-field modes) together with electron diffraction patterns and atomic force microscopy confirmed that this graphene material consisted mostly of mono-, bi- or few-layer graphene (less than ten layers). The high degree of surface reduction was confirmed by X-ray photoelectron and infrared spectroscopies. In addition, the high stability of the FLG in the liquid medium facilitates the deposition of the graphene material onto several substrates via low-cost solution-phase processing techniques, opening the way to subsequent applications of the material.
Tsinghua University Press
Izabela Janowska,Kambiz Chizari,Ovidiu Ersen,Spyridon Zafeiratos,Driss Soubane,Victor Da Costa,Virginie Speisser,Christine Boeglin,Matthieu Houllé,Dominique Bégin,Dominique Plee,Marc-Jacques Ledoux,Cuong Pham-Huu, Microwave synthesis of large few-layer graphene sheets in aqueous solution of ammonia. NanoRes.2010, 3: 126–137