▎ 摘　　要

NOVELTY - Preparing graphene oxide or graphite oxide comprises (i) adding concentrated sulfuric acid, graphite, potassium permanganate and water into the reaction kettle, stirring and controlling the reaction temperature and reaction time to obtain the graphene oxide or graphite oxide slurry, the salt in the graphene oxide or graphite oxide slurry to form a supersaturated state, (ii) purifying the graphene oxide or oxidized graphite slurry, separating and removing salt particles, (iii) performing purification treatment to the material to obtain the cake material with high solid content, dry material or slurry state material, (iv) mixing and dispersing the cake material, dry material or slurry state material with water to form the material with low solid content of slurry or solution state, (v) re-purifying the slurry or solution state to obtain the cake material with high solid content, dry material or slurry state material, and (vi) repeatedly executing the step (iv) and (v) for many times. USE - The method is useful for preparing graphene oxide or graphite oxide. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for device for producing graphene oxide or graphite oxide.