▎ 摘　　要

NOVELTY - A graphene preparation method comprises mixing surfactant and carbonate solvent, ultrasonic peeling, centrifuging, collecting supernatant, heating at 80-100 degrees C for 0.5-1 hour, filtering, and drying at 200-300 degrees C for 0.5-1 hour. USE - Graphene preparation method (claimed). ADVANTAGE - The method is suitable for expanded graphite. It has graphene sheet size of 3-50 mu m. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of expanded graphite comprising mixing nitric acid and phosphoric acid, stirring, water bath heating at 40-60 degrees C, adding oxidizing agent, water bath heating at 70-85 degrees C for 1-2 hours, adding deionized water, stirring, centrifuging, taking precipitate, water washing, and drying at 800-950 degrees C for 1-15 seconds.