▎ 摘　　要

NOVELTY - Preparing large graphene oxide sheet, comprises (i) intercalating the natural graphite flake with mixed acid solution, to obtain intercalated graphite, and heating the intercalated graphite; (ii) oxidizing the heat-treated intercalated graphite to obtain graphene oxide; and (iii) adding the graphene oxide into the solvent, sufficiently dissolving to obtain graphene oxide solution, adjusting the pH to less than 7, and then allowing to stand and centrifuging to obtain large graphene oxide sheet, and allowing to settle and separating. USE - The method is useful for preparing large graphene oxide sheet (claimed). ADVANTAGE - The method increases the oxidation efficiency.