▎ 摘　　要

NOVELTY - The method involves mixing graphite powder and an alkyl sulfonic acid solution under magnetic stirring according to the ratio of the mass (g) of the graphite powder to the volume (mL) of the alkyl sulfonic acid being 1: 100-150 to obtain a graphite-alkyl sulfonic acid dispersion liquid, where the alkyl sulfonic acid is any one of methanesulfonic acid and ethylsulfonic acid. A hydrogen peroxide solution is dropwise added into the dispersion under magnetic stirring, wherein the dropping speed is 2mL/min, and the total volume of the dropwise added hydrogen peroxide is 50-57% of the volume of the graphite-alkyl sulfonic acid dispersion. The ultrasonically treated dispersion is centrifuged, and repeatedly washed with deionized water until sulfate radicals are completely removed. The washed dispersion liquid is freeze-dried to obtain graphene solid powder. USE - Method for preparing graphene used in microelectronics, optics, magnetics, biomedicine, catalysis, energy storage, sensor material and multifunctional composite material. ADVANTAGE - The method prepares high quality of graphene, and does not generate harmful gas in the process, no harm to the environment, and low cost. The method avoids the use of concentrated acid in the current preparation method, and has little harm to environment. In the graphene prepared by the method, 1-10 layer accounts for 90-95 %, the yield is 87 %, and the product is oxidized degree is low, the prepared graphene defect is less, the method is simple, the cost is low and provides a new idea for realizing the macro preparation of graphene. The yield of the graphene is 87% (preferably 87-94%) and the number of product is few and the defect is low.