▎ 摘　　要

NOVELTY - Preparing graphene oxide comprises (i) adding graphite powder into concentrated sulfuric acid at low temperature, stirring and carrying out low temperature intercalation by ultrasonic processing, (ii) adding sulfuric acid solution into the obtained mixed solution, continuously introducing ozone-containing gas as oxidant, heating to constant temperature, stirring and reacting to realize medium temperature oxidation stripping, (iii) continuously introducing ozone-containing gas as oxidant and carrying out high-temperature oxidation stripping, and (iv) centrifugal separating, washing and drying. USE - The method is useful for preparing graphene oxide (claimed). ADVANTAGE - The method produces high purity product, realizes recycling of waste, and is safe and environmentally friendly. DETAILED DESCRIPTION - Preparing graphene oxide comprises (i) adding graphite powder into concentrated sulfuric acid at low temperature, stirring and carrying out low temperature intercalation by ultrasonic processing, (ii) adding sulfuric acid solution into the obtained mixed solution, continuously introducing ozone-containing gas as oxidant, heating to constant temperature, stirring and reacting to realize medium temperature oxidation stripping, (iii) continuously introducing ozone-containing gas as oxidant, adding strong oxidant solution, gradually heating to constant temperature, stirring and reacting at high-temperature environment to realize high-temperature oxidation stripping, and (iv) stopping introducing the ozone-containing gas, centrifuging the obtained mixed solution, separating upper layer clear liquid and lower layer suspension, subjecting the lower layer suspension to deep stripping to obtain the graphene oxide containing dispersion liquid, or deep stripping the lower layer suspension, centrifugal separating, washing and drying to obtain oxide graphene powder.