▎ 摘　　要

NOVELTY - Preparing nitrogen-doped graphene quantum dot involves dispersing graphene-reduced graphene in concentrated nitric acid, heating under magnetic stirring to 140-160 degrees C, circulating water condensing under constant temperature reaction for 12-48 hours, removing, circulating, condensing, evaporating at constant temperature for 1-2 hours, cooling to room temperature, adding ultra-pure water, ultrasonically dispersing for 10-15 minutes, filtering. USE - Method for preparing nitrogen-doped graphene quantum dot. ADVANTAGE - The method enables to prepare nitrogen-doped graphene quantum dot is good for the photoelectric, biological medicine and fields of potential applications, which improves the lighting stability, effectively simplifies the complicated passivation treatment and impurity element doping process in traditional doped quantum dot preparation process, improves the charge transfer capacity of the quantum dot. DETAILED DESCRIPTION - Preparing nitrogen-doped graphene quantum dot involves dispersing graphene-reduced graphene in concentrated nitric acid, heating under magnetic stirring to 140-160 degrees C, circulating water condensing under constant temperature reaction for 12-48 hours, removing, circulating, condensing, evaporating at constant temperature for 1-2 hours, cooling to room temperature, adding ultra-pure water, ultrasonically dispersing for 10-15 minutes, filtering, evaporating filtrate by rotary evaporation to the original volume of 1/9-1/10 into 3000-8000Da dialysis bags in dialysis for 24-48 hours. The dialysate is again concentrated by rotary evaporation and vacuum freeze-dried to obtain final product.