▎ 摘　　要

NOVELTY - The preparation method of nitrogen-doped graphene quantum dots involves (1) using citric acid and ethylenediamine as a raw material to prepare intermediate of nitrogen-doped graphene quantum dots through hydrothermal method, and (2) dehydrating and carbonizing the obtained intermediate through solvent-thermal method. USE - Preparation method of nitrogen-doped graphene quantum dots used for bioluminescent label, solar battery, and fuel cell (claimed). ADVANTAGE - The method enables preparation of nitrogen-doped graphene quantum dots with uniform size, excellent crystallinity, high nitrogen content, high fluorescence quantum yield, and excellent dispersibility in water and organic solvents, by simple, economical and industrial process.