▎ 摘　　要

NOVELTY - The preparation of graphene involves (1) peeling off graphite by supercritical carbon dioxide stripping method, dispersing obtained graphite powder in deionized water, homogenizing, controlling pressure of 90-150 MPa, dispersing and drying in sequence, (2) preparing graphene oxide powder, (3) dissolving graphene oxide powder in solvent, and adding chlorinating agent, reacting at -20-15 degrees C for 1-4 hours, increasing temperature to 50-120 degrees C for 12-24 hours, slowly adding appropriate amount of water, reacting until no gas is produced, filtering and washing, re-dispersing the filtered product in solvent, (4) dripping ethylenediamine to dispersion, reacting at 180-220 degrees C, controlling pressure of 0.25-0.6 MPa for 10-24 hours, carrying out suction filtration and washing, dispersing the filter cake in deionized water to obtain aqueous slurry of aminated graphene, and (5) drying the aqueous slurry of aminated graphene. USE - Preparation of graphene. ADVANTAGE - The method enables preparation of graphene ensuring small diameter, less number of layers and enhanced modification effect. DETAILED DESCRIPTION - The preparation of graphene involves (1) peeling off graphite by supercritical carbon dioxide stripping method, dispersing obtained graphite powder in deionized water, homogenizing, controlling pressure of 90-150 MPa, dispersing and drying in sequence, (2) soaking the dried product in dilute hydrochloric acid at -10-15 degrees C for 1-4 hours, where the mass ratio of dilute hydrochloric acid and graphite is (1-2.5):1, adding mixture of potassium dichromate and hydrogen peroxide, carrying out oxidation reaction at 10-85 degrees C for 2.5-6 hours, after the reaction is completed, washing with water, carrying out suction filtration, and drying to obtain graphene oxide powder, the mass ratio of graphite, potassium dichromate and hydrogen peroxide is 1:(0.1-0.9):(0.05-0.1), (3) dissolving graphene oxide powder in solvent, and adding chlorinating agent, reacting at -20-15 degrees C for 1-4 hours, increasing temperature to 50-120 degrees C for 12-24 hours, slowly adding appropriate amount of water, reacting until no gas is produced, filtering and washing, re-dispersing the filtered product in solvent, the mass ratio of chlorinating agent and graphene oxide powder is (0.3-2.8):1, (4) dripping ethylenediamine to dispersion, reacting at 180-220 degrees C, controlling pressure of 0.25-0.6 MPa for 10-24 hours, carrying out suction filtration and washing, dispersing the filter cake in deionized water to obtain aqueous slurry of aminated graphene, the mass ratio of ethylenediamine and chlorinating agent is (0.5-1.5):1, and (5) drying the aqueous slurry of aminated graphene.