▎ 摘　　要

NOVELTY - Preparing three-dimensional porous graphene oxide sponge comprises taking natural graphite flake and sodium nitrate, measuring sulfuric acid, mixing, stirring under ice bath conditions, taking potassium permanganate, adding to a reaction beaker, reacting, transferring the reaction beaker to a water bath, measuring deionized water, adding to reaction beaker, stirring, adding e.g. hydrogen peroxide, placing on a magnetic stirrer, stirring, washing with hydrochloride to remove sulfate radical, repeatedly washing with deionized water to obtain graphene oxide dispersion and placing the graphene oxide / para-aminosalicylate sodium composite in a tube furnace, heating, removing the para-aminosalicylate sodium template to obtain three-dimensional porous graphene oxide, adding deionized water, freeze-drying to obtain a lyophilized graphene oxide block, adding the freeze-dried graphene oxide block in a vacuum drying box and vacuum-drying to obtain three-dimensional porous graphene oxide sponge. USE - The method is useful for preparing three-dimensional porous graphene oxide sponge. ADVANTAGE - The method is simple; enables that the preparation process of the three-dimensional structure graphene oxide is easy; is easy to control the size and density of the three-dimensional pores; obtains three-dimensional graphene oxide sponges with different hole sizes and densities by using a solid template method and controlling process parameters; has high repeatability and is suitable for industrialized scale production. DETAILED DESCRIPTION - Preparing three-dimensional porous graphene oxide sponge comprises (a) taking 5-10 g natural graphite flake and 2.5-5 g sodium nitrate, measuring 130-260 ml sulfuric acid, mixing evenly, continuing stirring under ice bath conditions, taking 15-30 g potassium permanganate, adding to a reaction beaker, reacting for 2-4 hours, transferring the reaction beaker to a water bath at 30-40 degrees C for 0.5-2 hours, increasing the reaction to 90-120 degrees C, measuring 200-400 ml deionized water, adding to the reaction beaker, continuing stirring for 0.5-1 hour, increasing the reaction to 90-120 degrees C, measuring 200-400 ml deionized water, adding to the reaction beaker, continuing stirring for 0.5-1 hour, adding 200-400 ml deionized water and 230-460 ml hydrogen peroxide, placing on a magnetic stirrer, stirring for 0.5-1 hour, washing with hydrochloride to remove the sulfate radical, repeatedly washing with deionized water to pH 7 to obtain graphene oxide dispersion, (b) measuring 8-15 ml polystyrene microsphere dispersion, adding it to a beaker, turning on magnetic stirring in an oil bath, preparing nitric acid and sulfuric acid in a ratio of 2:3, firstly measuring 4-8 ml nitric acid, placing in a beaker, measuring 6-12 ml sulfuric acid, slowly adding to nitric acid, stirring continuously by a glass rod, adding the prepared mixed acid to the polystyrene emulsion for nitration, reacting for 2-4 hours, repeatedly filtering the prepared reaction solution with a circulating vacuum pump until the pH value is neutral, placing the obtained product in a drying oven, drying to obtain a light yellow powder, labeled as polynaphthalene sulfonate, (c) adding the polynaphthalene sulfonate microsphere powder obtained in the previous reaction in a beaker, placing in an oil bath at 70-90 degrees C, turning on magnetic stirring, adding 60-120 ml sodium hydroxide solution and 3-6 g reducing agent sodium dithionite, reacting for 3-5 hours, washing the reaction mixture with a pH of 7 with a circulating vacuum pump, drying the obtained product in a drying oven to obtain a light yellow powder, labelled as para-aminosalicylate sodium, (d) taking 0.18-0.36 g para-aminosalicylate sodium powder, adding 0.9-1.8 ml deionized water to prepare 2 wt.%. para-aminosalicylate sodium microsphere emulsion, adding different concentrations of graphene oxide dispersions (0.5 mg/ml, 1mg/ml, 3mg/ml, 5mg/ml, 7mg/ml, 9mg/ml), mixing according to the ratio of 1:1, performing ultrasound to make graphene oxide coating the surface of para-aminosalicylate sodium microspheres, centrifuging the mixed solution, removing the supernatant liquid from the upper layer, placing in a drying oven, drying, taking out the reaction material, grinding into powder, labelled as graphene oxide / para-aminosalicylate sodium and (e) placing the graphene oxide / para-aminosalicylate sodium composite in a single-channel tube furnace, heating in an inert gas atmosphere to 400-600 degrees C at a rate of 5-8 degrees C/minute for 1-3 hours, removing the para-aminosalicylate sodium template to obtain three-dimensional porous graphene oxide, adding 200-400 ml deionized water, freeze-drying the obtained graphene oxide solution at -10 to -20 degrees C for 24-48 hours to obtain a lyophilized graphene oxide block, adding the freeze-dried graphene oxide block in a vacuum drying box and vacuum-drying at 80-100 degrees C for 20-28 hours to obtain a three-dimensional porous graphene oxide sponge, where in the steps (a) and (c) the ratio of natural graphite flakes, sodium nitrate , potassium permanganate and sodium dithionite is: (2-2.5):1:6:(1-1.2). In the steps (a) and (c) the ratio of sulfuric acid, hydrogen peroxide and sodium hydroxide is (10-15):1:6. In the step (a) the ratio of sulfuric acid, sodium nitrate and natural graphite flakes is 2:1 (16-18).