▎ 摘　　要

NOVELTY - The preparation method of graphene involves adding ethanol to mixture of phenolic resin and iron salt, stirring, drying, adding hexamethylenetetramine, adding acetone, ultrasonically processing, drying by airing, curing, and carbonizing under nitrogen protection to obtaining carbon-coated iron nanoparticles, heating the obtained particles under argon gas atmosphere, heat-preserving, and graphitizing to obtain graphitized hollow carbon nanospheres, (2) pre-oxidizing graphitized hollow carbon nanospheres with mixing acid, adding potassium permanganate, and stirring. USE - Preparation method of graphene (claimed). ADVANTAGE - The method enables preparation of graphene with excellent quality and yield, by simple and efficient process. DETAILED DESCRIPTION - The preparation method of graphene involves (1) adding ethanol to mixture of phenolic resin and iron salt, stirring for 4-8 hours, drying at room temperature, adding hexamethylenetetramine, adding acetone, ultrasonically processing for 20-60 minutes, drying at room temperature by airing, curing at 140-160 degrees C for 3-5 hours, and carbonizing under nitrogen protection to obtaining carbon-coated iron nanoparticles, heating the obtained particles at 2500-3000 degrees C under argon gas atmosphere, heat-preserving for 1-3 hours, and graphitizing to obtain graphitized hollow carbon nanospheres, (2) pre-oxidizing graphitized hollow carbon nanospheres obtained in step (1) with mixing acid, adding potassium permanganate, stirring at room temperature for 0.5-2 hours, heating at 50-60 degrees C, stirring for 1-2 hours, adding deionized water, terminating hydrogen peroxide and potassium permanganate to obtain solution of graphite oxide, filtering, washing with 4-8 wt.% acetic acid solution, washing precipitate with deionized water, adding deionized water to the precipitate, and ultrasonically dispersing for 2 hours to obtain aqueous solution of graphene oxide, (3) centrifuging the aqueous solution of graphene oxide obtained in step (2), and drying upper layer of graphene oxide aqueous solution at 60-70 degrees C in oven to obtain oxidized graphene, and (4) subjecting the graphene oxide obtained in the step (3) to thermal reduction at high temperature of 1000-1100 degrees C, heat-preserving for 20-60 seconds, removing oxidized graphene particles by sieving, ultrasonically dispersing graphite and ethanol mixture, drying at room temperature, and drying at 120-150 degrees C for 6-8 hours under vacuum condition.