▎ 摘　　要

NOVELTY - Preparing sulfur-nitrogen co-doped graphene quantum dot comprises dispersing the network-shaped reduced graphene oxide and thiourea in concentrated nitric acid, heating to 140-160 degrees C in an oil bath under magnetic stirring, circulating water condensation under constant temperature reaction for 12-48 hours; removing the circulating condensed water, continuously evaporating at constant temperature for 1-2 hours, cooling to the room temperature; adding ultrapure water, carrying ultrasonic dispersion for 10-15 minutes; filtering, concentrating the filtrate by rotary evaporation to 1/9-1/10 of original volume, placing in 3000-8000 Da dialysis bag, carrying dialysis for 24-48 hours; again concentrating the dialysate by rotary evaporation, vacuum freeze-drying to obtain stable sulfur-nitrogen co-doped graphene quantum dots. USE - The quantum dot is useful for optoelectronics and biomedicine fields. ADVANTAGE - The method: can improves luminescence stability of graphene quantum dots to some extent, actively simplifies complex passivation treatment and impurity element doping process in preparation process of traditional doped quantum dots, and actively improves the charge transfer capability of quantum dots.