Highly Efficient Synthesis Of Carbon Nanosheets By Ultrasonication

Two-dimensional carbon nanosheets and graphene, new forms of carbon materials,have unique crystal structure and very peculiar physical, chemical and mechanicalproperties, which gives them many potential applications in the field of electricalengineering. The research about the synthesis of carbon nanosheets and graphene is nowa hot field and there are endless stream of new preparation methods. However, there isstill no method with high production, process safety as well as low product de fects.Therefore, the high yield, low-cost and safe synthesis methods of high quality carbonnanosheets and graphene have become the goal and focus of the current research in thefield.In this paper, we focused on improving the safety and efficiency of the existingpreparation methods and developed two kinds of highly efficient synthesis of carbonnanosheets and grapheme through ultrasonication under guidance of intercalatedgraphite theory. We explored how to choose the intercalation reagents, media and solidparticles to assist to improve the efficiency of stripping by the ultrasonic method fromtwo directions, namely, how to use the intercalation reagent auxiliary solvent toimprove the efficiency of ultrasonic stripping and how to use graphite interca lationreagent (bromine) on the intercalation mainly to improve the stripping efficiency. FeCl3,CuCl2and other common intercalation reagents as well as nano-SiO2powders in fourdifferent liquids were selected to assist ultrasonic stripping, thereby enha ncing thestripping efficiency. X-ray diffraction (XRD), and Raman spectroscopy (RAMAN)were applied to analyze the phase composition and crystal structure of the preparedcarbon nanosheets (graphene) and composite powders. Scanning electron microscopy(SEM) and transmission electron microscopy (TEM) were used to characterize thenanostructure and morphology.XRD analysis of all the prepared samples showed that (002) plane diffraction peakof graphite decreased. This phenomenon is especially significant in the glycol-ferricchloride system and the bromine-isopropyl alcohol system, which indicates that thegraphite has been effectively exfoliated. RAMAN analysis of graphite showed theprepared carbon nanosheets had few defects. The SEM analysis of the prepared carbonnanosheets showed some transparent few-layer grapheme and a lot of graphene werefolded. TEM analysis showed that the carbon nanosheets and graphene had good crystalstructure and there were some nano sheets with layers no more than5, in which most of the prepared carbon nanosheets were folded and have about10layers.