Ultrafast in-situ transformation of graphite into graphene nanosheets by high current pulsed electron beam direct irradiation

Abstract Environmental-friendly and efficient transformation of graphite to obtain impurity-free graphene remains challenging. Herein, a novel approach for in-situ transformation of graphite into graphene is proposed. The graphite particles were irradiated directly by high current pulsed electron beam (HCPEB) with pulse duration of 2 μs. The morphology and microstructure changes were characterized by Raman spectrum, X-ray diffraction, confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscope (AFM) methods. It is revealed that the surface layer on graphite particles of thickness ∼10 μm was transformed to graphene nanosheets effectively, where the content of graphene with thickness less than 10 atom layers reached 95%. The numerical simulation results showed that the heating temperature in the subsurface layer would be 3246 ℃ and the thermal stress amplitude ∼110 MPa, which leads to the instantaneous expansion and breakdown of interlayer combination and realizes the transformation of graphite into graphene microstructure. This study demonstrated the potential of using HCPEB for ultrafast in-situ transformation of graphite into graphene nanosheets.