▎ 摘　　要

NOVELTY - Preparation of graphene oxide sheet comprises cooling concentrated sulfuric acid to 0 degrees C with stirring, adding successively graphite, potassium permanganate and sodium nitrate and stirring; heating to 25 degrees C and stirring for 2.5-3.5 hours; heating to 35 degrees C and stirring for 0.5-4 hours; cooling to 0 degrees C for 1.5-2.5 hours and adding successively deionized water and hydrogen peroxide solution; and washing, centrifuging and drying. USE - Method for preparing graphene oxide sheet (claimed). ADVANTAGE - The method has high oxidation degree and short processing time.