▎ 摘　　要

NOVELTY - Preparation of graphene oxide involves expansion-foaming squamous graphite powder using concentrated sulfuric acid as intercalation agent (a1) at room temperature, adding sulfate and phosphate respectively as intercalation agents (a2) and (a3), stirring for 12-48 hours to obtain mixed solution (A), slowly adding potassium permanganate as oxidizing agent to the mixed solution (A) for 15-45 minutes, heating to medium temperature of 25-50 degrees C, stirring for 4-10 hours, slowly adding hydrogen peroxide with concentration of 10-30% until no bubbles are formed, heating to 50 degrees C for 1-6 hours to obtain mixed solution (B), centrifugally washing to pH of 5.0-7.4 with 0.1-2 M hydrochloric acid aqueous solution and deionized water, and freeze-drying resultant precipitate. The molar ratio of sulfate and phosphate is 1:1-25:1. The mass ratio of graphite powder and intercalation agent (a1) is 1:1-1:550. The mass ratio of graphite powder and potassium permanganate is 1:1-1:10. USE - Preparation of graphene oxide used for preparing reduced graphene. ADVANTAGE - The method enables simple, economical and easy preparation high-quality graphene oxide having high oxidation degree and low defect density, with high productivity on large-scale.