▎ 摘　　要

NOVELTY - Preparing graphene oxide involves (a) mixing graphite with concentrated sulfuric acid to obtain a mixture (A), (b) adding an expansion agent to the mixture A, vacuumizing, reacting under the vacuum to obtain mixture (B), (c) adding oxidant into the mixture B, heating and vacuumizing and reacting in the vacuum to obtain the mixture (C), (d) filtering the mixture C and washing to obtain graphene oxide, and (e) washing the mixture. USE - Preparation method of graphene oxide used in biomedicine, flexible conductive film, liquid crystal optical material, and energy storage material. ADVANTAGE - The method accelerates the reaction rate by vacuumizing process and reduces the dosage of the oxidant, reduces the oxidation time to 2 hours, saves the energy consumption and cost.