▎ 摘　　要

An improved method for the preparation of graphene quantum dots (GQDs) is described. The samples are characterized in terms of morphological, structural, and optical properties which are evaluated by X-ray diffraction (XRD), transmission electron microscopy (TEM), the Photoluminescence (PL) spectrum and Fourier transform infrared (FTIR) spectra correspondingly. The graphene oxide (GO) go through with microwave expansion treatment first, then followed by solvothermal process. The research shows that with the increase of the microwave time and microwave power, the fluorescence intensity of GQDs first increased and then decreased, when the GO sheets are under 500 W microwave-assisted treatment for 5 min, the intensity gets the strongest. The solvothermal temperature had no effect on the fluorescence emission wavelength of the graphene quantum dots, the fluorescence emission spectra red shifts as the microwave treatment time is increased. The fluorescence emission spectrum of GQDs that synthesized by this method perform excitation-dependent PL behaviors.