▎ 摘　　要

NOVELTY - The preparation method of graphene quantum dots involves (1) mixing graphite oxide with sodium persulfate in N,N-dimethylformamide, (2) stirring the mixture solution obtained in the step (1), and carrying out ultrasonic dispersion to uniformly disperse, (3) transferring the uniformly dispersed mixture to a hydrothermal reactor to react, (4) cooling the product obtained in the step (3) to room temperature, filtering to remove unreacted graphite oxide through a porous filter membrane to obtain mixed solution containing graphene quantum dot, (5) placing the mixed solution containing graphene quantum dots in a dialysis bag to obtain graphene quantum dot aqueous solution, and (6) freeze-drying the graphene quantum dot aqueous solution. USE - Preparation method of graphene quantum dots by acid-free method. ADVANTAGE - The method enables method preparation of graphene quantum dots with high yield and productivity, and which does not need neutralization of strong acid oxidation and alkali addition, by simple process.