▎ 摘　　要

NOVELTY - The preparation method of carbon nitride quantum dots nano-graphene hydrogel composite material involves (1) mixing graphitic carbon nitride with 10 ml concentrated sulfuric acid, stirring at 100 degrees C for 2 hours, dripping carbon nitride/sulfuric acid into graphene oxide solution, obtaining a mixture, (2) transferring the resulting mixture into an ultrasonic reactor, hydrothermally reacting under specified conditions for certain time. USE - Preparation of carbon nitride quantum dots nano-graphene hydrogel composite material used for fuel cell, hydrogen storage carrier and biological sensor.