▎ 摘　　要

NOVELTY - Preparation method of graphene oxide involves adding potassium persulfate, phosphorus pentoxide and magnetic particles to a single-necked flask, slowly adding concentrated sulfuric acid, shaking the flask so that the compound is dissolved in concentrated sulfuric acid, adding flake graphite to the mixed solution, placing the flask in an oil bath, heating at 80 degrees C, magnetically stirring, cooling the mixture to room temperature, dripping the mixture into a beaker filled with deionized water, washing, carrying out suction filtration and naturally drying to obtain pre-oxidized graphite. USE - Method is useful for preparing graphene oxide (claimed). ADVANTAGE - The method ensures simple and convenient preparation of graphene oxide with improved quality and comprehensive performance. DETAILED DESCRIPTION - Preparation method of graphene oxide involves (a) adding 2.5 g potassium persulfate, 2.5 g phosphorus pentoxide and magnetic particles to a 100 ml single-necked flask, slowly adding 12 ml concentrated sulfuric acid, shaking the flask so that the compound is dissolved in concentrated sulfuric acid, adding 3 g flake graphite to the mixed solution, placing the flask in an oil bath, heating at 80 degrees C, magnetically stirring, cooling the mixture to room temperature, dripping the mixture into a beaker filled with 1 l deionized water, washing, carrying out suction filtration and naturally drying to obtain pre-oxidized graphite, (b) cooling a beaker containing 120 ml concentrated sulfuric acid and magnetic seed to 0 degrees C using ice water, adding pre-oxidized graphite, uniformly stirring, adding 15 g potassium permanganate, maintaining the temperature of the reaction system at below 20 degrees C, stirring for 2 hours, dripping 250 ml deionized water under the condition of ice water bath to dilute, maintaining the temperature of reaction system at below 35 degrees C, stirring at room temperature for 2 hours, adding 700 ml distilled water for dilution, adding hydrogen peroxide under magnetic stirring condition until the liquid becomes bright yellow, stopping dripping, leaving for 2 hours, clarifying upper layer, pouring out the supernatant, precipitating lower layer yellow precipitates, washing with 100 ml dilute aqueous hydrochloric acid solution, removing residual metal ions, leaving, clarifying the upper liquid, pouring out supernatant and continuously repeating the above process using distilled water until the pH value of the solution is weakly acidic to obtain lower-layer product as graphite oxide, (c) shearing a dialysis bag with a length of 10 cm, soaking the dialysis bag in distilled water for 30 minutes, taking out, tightening one end of the dialysis bag using a cotton thread, placing graphite oxide in the dialysis bag, tightening other end of the dialysis bag using the cotton thread, placing the dialysis bag in a large beaker filled with 1 l distilled water, carrying out dialysis for 5-7 days, replacing water every 8 hours, measuring real-time pH value, stopping dialysis when the pH value of the graphite oxide is neutral, taking out graphite oxide, pouring the prepared graphite oxide gel into a glass vessel, placing the glass vessel into a vacuum drying box, heating at 60 degrees C, drying for 1 day, putting 20 g phosphorus pentoxide into a culture dish as a dehydrating agent, vacuumizing using an oil pump and drying at 60 degrees C for 2 days to remove residual moisture in the graphite oxide, and (d) dispersing 0.5 g purified graphite oxide in 20 g water and carrying out ultrasonic treatment at a power of 100 W for 1 hour to obtain graphene oxide dispersion liquid.