▎ 摘　　要

NOVELTY - Preparation method of graphene involves (a) reacting graphite, chromium trioxide and concentrated hydrochloric acid to obtain intercalated graphite compound, (b) mixing the intercalated graphite compound with hydrogen peroxide to obtain expanded graphite, and (c) stripping the expanded graphite in an aqueous phase to obtain graphene. USE - Method is useful for preparing graphene (claimed). ADVANTAGE - The method ensures economical preparation of graphene with high dispersion speed, and without the organic solvent pollution to the environment.