▎ 摘　　要

NOVELTY - Preparation of large surface area and less layers graphene involves dispersing graphite powder in mixed acid of phosphoric acid and nitric acid, adding strong oxidizer potassium permanganate, reacting at 25-30 degrees C for 1-1.5 hours, filtering, washing, drying, dispersing in acetic acid and nitric acid, adding potassium permanganate, reacting at 25-30 degrees C for 1-1.5 hours, filtering, washing, and drying; and calcining at 900-950 degrees C for 25-30 seconds, dispersing in dimethylformamide, ultrasonic treating for 20-24 hours, filtering, washing, and drying. USE - Method for preparing large surface area and less layers graphene (claimed) used for preparing graphene composite material. ADVANTAGE - The graphene has 5 number of layers and specific surface area of 150-200 mu m. DETAILED DESCRIPTION - Preparation of large surface area and less layers graphene comprises dispersing graphite powder in mixed acid of phosphoric acid and nitric acid, adding strong oxidizer potassium permanganate, reacting at 25-30 degrees C for 1-1.5 hours, filtering, washing, drying, dispersing in acetic acid and nitric acid, adding potassium permanganate, reacting at 25-30 degrees C for 1-1.5 hours, filtering, washing, and drying; calcining at 900-950 degrees C for 25-30 seconds, dispersing in dimethylformamide, ultrasonic treating for 20-24 hours, filtering, washing, and drying; adding to sulfuric acid and phosphoric acid at 0-5 degrees C, stirring, adding potassium permanganate, stir-heating at 50-55 degrees C for 10-12 hours, putting in ice bath, stirring, adding hydrogen peroxide until golden yellow in color, adding hydrochloric acid, repeatedly washing with ethanol and water, centrifuging, and drying; and dispersing in water, adjusting pH to 12-13, adding hydrazine hydrate, reacting for 12-14 hours at 98-100 degrees C, washing, and drying.