▎ 摘　　要

NOVELTY - Improved preparation process of sulfonated graphene comprises (a) adding concentrated sulfuric acid into a flask, condensing and refluxing, mechanically stirring, adding graphite powder, potassium sulfate and phosphorus pentoxide, stopping heating, naturally cooling to room temperature, vacuum filtering, collecting the filter cake, drying, (b) adding concentrated sulfuric acid, cooling by ice bath, adding the pre-oxidized product into the flask, performing electric stirring, adding potassium permanganate, adding hydrogen peroxide in stirring state, (c) allowing to stand the mixture for 4 days, pouring the supernatant, centrifuging and filtering the lower layer mixture, washing, dispersing the oxide in water, ultrasonically processing, freezing and drying and (d) mixing the sulfonating agent and the graphene oxide, dispersing the mixture uniformly in the water and filtering and drying to obtain the sulfonated graphene. USE - The method is useful for improved preparation process of sulfonated graphene. ADVANTAGE - The method: controls the reaction time, the reaction temperature and the amount of oxidant to prepare graphite oxide with different oxidation degrees; adopts the ultrasonic-assisted peeling method to improve the production efficiency of graphene oxide nanosheets and sulfonates the prepared graphene oxide with a sulfonating agent to prepare the required sulfonated graphene. DETAILED DESCRIPTION - Improved preparation process of sulfonated graphene comprises (a) adding 40 ml concentrated sulfuric acid into a 500 ml flask, condensing and refluxing, mechanically stirring, adding 10 g graphite powder, 8.4 g potassium sulfate and 8.4 g phosphorus pentoxide at 80 degrees C, stirring uniformly for 5-8 minutes, keeping for 4-5 hours at 80 degrees C, stopping heating, naturally cooling to room temperature, slowly adding 250 ml deionized water to dilute in the flask, where the deionized water temperature is not greater than 80 degrees C, allowing to stand for more than 12 hours, vacuum filtering, collecting the filter cake, washing with deionized water to neutral, drying at 60 degrees C to obtain oxidized graphite intermediate, (b) adding 230 ml concentrated sulfuric acid into the three-mouth flask with capacity of 1 l, cooling to 0 degrees C by ice bath, adding the pre-oxidized product into the flask, performing electric stirring, slowly adding 45 g potassium permanganate, controlling the addition of the potassium permanganate in the process at 6-10 degrees C, heating to 35 degrees C, keeping for 2 hours, using deionized water to dilute and stirring for 2 hours, transferring the solution to the beaker, adding 1000 ml deionized water, adding 25 ml hydrogen peroxide in stirring state, where the solution is bright yellow, (c) allowing to stand the mixture for 4 days, pouring the supernatant, centrifuging and filtering the lower layer mixture, washing by a large amount of water, washing with hydrochloric acid for more than 3 times, washing to neutral, dispersing the oxide in water, ultrasonically processing for 30 minutes to obtain the aqueous solution of graphene oxide, freezing and drying to obtain the graphene oxide and (d) mixing the sulfonating agent and the graphene oxide, dissolving in the deionized water, dispersing the mixture uniformly in the water and filtering and drying to obtain the sulfonated graphene.