▎ 摘　　要

NOVELTY - A graphite oxide acid solution having concentration of 0.5-4 mg/mL is prepared by providing expanded graphite as raw material and subjecting to ultrasonic processing. The resulted product is heated in a sealed container, and reduced by microwave digestion using high temperature pressurizing method. The resulted product is washed using water, and dried, to obtain graphene. USE - Preparation of graphene (claimed). ADVANTAGE - The graphene having high purity and large specific surface area is prepared by simple, environmentally-friendly and efficient process within short period of time without using graphite raw material having high purity and chemical reagent for reduction process.