▎ 摘　　要

NOVELTY - Nitrogen-doped graphene fluorescence quantum dots, is claimed. The nitrogen-doped fluorescent graphene quantum dots are spherical, particle size is 3-10 nm. The interplanar spacing of the quantum dots is 0.34 nm, 0.21 nm, corresponding to 002 and 100 facets of graphene, respectively. The nitrogen-doped fluorescent graphene quantum dot solution is colorless and transparent and launch a strong blue-violet fluorescence. The maximum excitation wavelength is 360-380 nm. The maximum emission peak is 440-460 nm and quantum yield is 22-31%. USE - Used as nitrogen-doped graphene fluorescence quantum dots. ADVANTAGE - The quantum dots simple, stable and has good water solubility. DETAILED DESCRIPTION - Nitrogen-doped graphene fluorescence quantum dots, is claimed. The nitrogen-doped fluorescent graphene quantum dots are spherical, particle size is 3-10 nm. The interplanar spacing of the quantum dots is 0.34 nm, 0.21 nm, corresponding to 002 and 100 facets of graphene, respectively. The nitrogen-doped fluorescent graphene quantum dot solution is colorless and transparent and launch a strong blue-violet fluorescence. The maximum excitation wavelength is 360-380 nm. The maximum emission peak is 440-460 nm and quantum yield is 22-31%. The quantum dots solid powder emit strong blue fluorescence, its best excitation wavelength is 360-380 nm, maximum emission peak is 420-450 nm. The solid is stored at room temperature for more than three months. An INDEPENDENT CLAIM is also included for preparing nitrogen - doped graphene fluorescence quantum dots comprising: (i) mixing of 0.0003-0.0012 M pure glycine with 35-41 ml ultra-pure water, stirring for 5-10 minutes, adding 9-15 ml 0.1M/l sodium citrate solution to obtain a colorless transparent solution; (ii) charging into a high pressure reactor lined with polytetrafluoroethylene, reacting at 160-200 degrees C for 8-14 hours, centrifuging at 9000-12000 rotations/minutes for 5-10 minutes, collecting supernatant i.e. nitrogen-doped ferrite fluorescent quantum dots solution; (iii) subjecting supernatant to rotary evaporation, carrying out vacuum freeze-drying to obtain nitrogen-doped graphene fluorescent quantum dot as a white solid powder.