▎ 摘　　要

NOVELTY - Preparation of graphene quantum dot involves taking natural graphite powder, adding sodium nitrate, 96% concentrated sulfuric acid and potassium permanganate, stirring at low temperature for 3.5 hours, heating to 45 degrees C for 60 minutes, then to 100 degrees C for 20-30 minutes, adding deionized water, diluting, adding 10% hydrogen peroxide, stirring, filtering, washing to neutral, and drying at 65 degrees C; dissolving in deionized water, ultrasonic oscillating for 2 hours, adding ammonia solution, reacting at 200 degrees C for 12 hours, and filtering. USE - Method for preparing graphene quantum dot used for photoluminescence diode (claimed). ADVANTAGE - The method is simple and controllable. The graphene quantum dot has uniform core-shell structure, small grain diameter size, thin shell layer, narrow fluorescence emission peak and high intensity. DETAILED DESCRIPTION - Preparation of graphene quantum dot comprises taking natural graphite powder, adding sodium nitrate, 96% concentrated sulfuric acid and potassium permanganate, stirring at low temperature for 3.5 hours, heating to 45 degrees C for 60 minutes, then to 100 degrees C for 20-30 minutes, adding deionized water, diluting, adding 10% hydrogen peroxide, stirring, filtering, washing to neutral, and drying at 65 degrees C; dissolving in deionized water, ultrasonic oscillating for 2 hours, adding ammonia solution, reacting at 200 degrees C for 12 hours, and filtering; stirring precursor solution of 10m zinc acetate at room temperature, adding 0.5 ml newly prepared 0.5 M sodium hydroxide in anhydrous ethanol solution, reacting, taking out, and cooling with ice; and mixing above products, heating at 120 degrees C for 3 hours, centrifugal washing, drying, and coating with zinc oxide.