▎ 摘　　要

NOVELTY - Preparation of graphene oxide involves mixing natural flake graphite, potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, carrying out ultrasonic dispersion, magnetically stirring, washing, filtering, vacuum drying, grinding, adding potassium permanganate, stirring, adding deionized water, stirring, settling, centrifuging, removing supernatant, washing with anhydrous ethanol, adjusting pH value to 6.0-6.5, collecting precipitate, drying to obtain purified graphite oxide, mixing purified graphite oxide and water, carrying out ultrasonic dispersion and spray-drying. USE - Method for preparing graphene oxide (claimed). ADVANTAGE - The method is energy-saving. DETAILED DESCRIPTION - Preparation of graphene oxide comprises mixing 1 pt. wt. natural flake graphite, 1 pt. wt. potassium persulfate, 1 pt. wt. phosphorus pentoxide and 10 ml concentrated sulfuric acid, carrying out ultrasonic dispersion at 80 degrees C for 5 minutes, placing in oil bath, magnetically stirring for 6 hours, washing, filtering, vacuum drying, grinding, placing in beaker, adding 50 ml concentrated sulfuric acid, carrying out ultrasonic dispersion, adding 6 pts. wt. potassium permanganate, stirring for 4 hours, adding 100 ml deionized water, maintaining temperature at 40 degrees C, stirring in water bath for 2 hours, adding 300-1000 ml deionized water and 8 ml hydrogen peroxide to obtain bright yellow suspension, stirring for 10 minutes, settling for 1-2 hours, pouring out supernatant, centrifuging, removing supernatant, adding precipitate with ethanol, stirring or carrying out ultrasonic dispersion, centrifuging, removing supernatant, washing with anhydrous ethanol, centrifuging for 2-3 times, adjusting pH value to 6.0-6.5, collecting precipitate, drying to obtain purified graphite oxide, mixing purified graphite oxide and water at mass ratio of 1:500-1000, carrying out ultrasonic dispersion for 1-3 hours with power of 500 W and spray-drying.