▎ 摘　　要

NOVELTY - Preparation of graphene comprises taking flake graphite, mixing with concentrated sulfuric acid and potassium permanganate, heating, adding aqueous solution of hydrogen peroxide, stirring for 0.5-2 hours, filtering, washing with water until pH value is 6-7, formulating solid into 2-5 g/mL suspension, carrying out ultrasonication for 20-40 minutes, standing for 12-48 hours, separating, dehydrating until liquid volume is 1/3, concentrating, refluxing with hydrazine hydrate for 18-24 hours, cooling, filtering and drying. USE - Method for preparing graphene (claimed). ADVANTAGE - The product is highly efficient and has low cost.