▎ 摘　　要

NOVELTY - Preparation of graphene oxide involves (i) oxidizing mineral graphite with at least one intercalating agent and an oxidizing agent by ultrasonically heating at 45-60 degrees C for 5-40 minutes, (ii) diluting with water in a volume of 5-30 times with respect to obtained material, (iii) adding hydrogen peroxide in a graphite-hydrogen peroxide ratio of 1:10-1:30 g/mL, (iv) washing the obtained material by initially adding hydrochloric acid and continuously water, filtering or centrifuging until the material reaches the pH of 5-7, and (iv) exfoliating the obtained mixture in polar protic or polar aprotic solvents by ultrasonically heating for 1-120 minutes at 30-80 degrees C. In step (i), the ratio of graphite and intercalating agent is 1:10-1:50 g/mL, and the ratio of graphite and oxidizing agent is 2:1-1:10 g/g. USE - Preparation of graphene oxide (claimed) as graphene oxide nanofoils. Uses include but are not limited to polymer composites, water treatment materials, supercapacitors, solar cells, catalyst and anticorrosive films. ADVANTAGE - The method consumes less energy, ensures short time for oxidation and exfoliation, provides high-quality nanomaterial with high operational efficiency and high yield, and provides graphene oxide nanofoils with high exfoliation degree, oxidation degree, graphene oxide concentration and excellent lateral area preservation. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for graphene oxide, which has an average exfoliation degree of 2-3 layers, oxidation degree of 38-45 %mass, peak of maximum degradation ratio at greater than 540 degrees C, lateral dimensions average of 5-15 mu m, and graphene oxide concentration of 5-10 g/L.