▎ 摘　　要

NOVELTY - Preparing graphene oxide comprises e.g. adding natural flake graphite into three-necked flask containing concentrated sulfuric acid, carrying out Hummers oxidation treatment under ice water bath, adding potassium permanganate, adding deionized water, adding hydrogen peroxide until mixture changes from dark brown to bright yellow and no bubbles are generated, washing mixture obtained in step (i), separating, removing acid waste solution in which small amount of graphene oxide is dissolved, adding hydrochloric acid solution to wash mixture, adding hydrochloric acid into oxidized graphite. USE - The method is useful for preparing graphene oxide (claimed). ADVANTAGE - The method has simple method, high yield and graphene oxide satisfies subsequent test needs. DETAILED DESCRIPTION - Preparing graphene oxide comprises (i) adding 6 g natural flake graphite into three-necked flask containing 120 ml concentrated sulfuric acid, carrying out Hummers oxidation treatment under ice water bath at 0 degrees C, stirring for half an hour, adding 18 g potassium permanganate, stirring at 0 degrees C for half an hour, controlling temperature not greater than 20 degrees C, stirring for 2 hours, not greater than 35 degrees C for 2 hours at room temperature, adding deionized water until reaction bottle is not sputtering phenomenon, stirring for half an hour, adding 30% hydrogen peroxide until mixture changes from dark brown to bright yellow and no bubbles are generated, (ii) washing mixture obtained in step (i), separating, removing acid waste solution in which small amount of graphene oxide is dissolved, adding 5-10% hydrochloric acid solution to wash mixture until there is no longer sulfate, adding hydrochloric acid into oxidized graphite, adding ammonia to adjust pH value to neutral, then repeatedly washing with deionized water, testing with silver nitrate solution without chlorine appearance, and washing to neutral product sedimentation separation or centrifuging solid-liquid separation to obtain viscous oxide graphite, brown colloid, placing obtained oxidized graphite in vacuum freeze-drying apparatus and subjecting to drying treatment to obtain oxidized graphite flocculent solid, and (iii) taking dried graphite oxide flocculent powder, dissolving in deionized water, stirring, and then ultrasonically cleaning to ultrasonic intensity of 90-105 w, ultrasonicating for 1-2 hours, and stripping oxidized graphite sheet to obtain pale yellow graphite oxide suspension.