▎ 摘　　要

NOVELTY - Preparing nitrogen-doped three-dimensional graphene-supported manganese(IV) oxide catalyst comprises, (i) preparing graphene oxide solution by using improved Hummers method, then drying and cutting into pieces, (ii) (a) adding the graphene oxide powder into deionized water, and ultrasonic dispersing, (b) mixing the graphene oxide solution, ethylenediamine and sodium borate solution, and then ultrasonically dispersing, (c) placing the mixture into a high-pressure hydrothermal kettle lined with polytetrafluoroethylene, then heating and naturally cooling, (d) pre-freezing the reaction product I and then naturally drying, (iii) (a) placing the highly elastic nitrogen-doped three-dimensional graphene aerogel into the high-pressure hydrothermal kettle lined with polytetrafluoroethylene, then immersing in the potassium permanganate solution and heat-treating (b) washing the reaction product II with deionized water, soaking and drying in oven. USE - The manganese(IV) oxide catalyst is useful in ozone catalytic oxidation system (claimed). ADVANTAGE - The method solve the problems of long-term soaking of the existing catalysts that the structure is often loose and the effect of improving the ozone catalytic oxidation treatment of refractory organics is poor. The catalyst: has high elasticity and mechanical strength, excellent catalytic effect, target pollutant treatment efficiency of 88% in 15 minutes and is close to 100% at 25 minutes, high treatment efficiency, and excellent salinity, single ozonation TOC removal rate increased by about 47%; and is suitable for the removal of difficult-to-degrade pollutants. DETAILED DESCRIPTION - Preparing nitrogen-doped three-dimensional graphene-supported manganese(IV) oxide catalyst comprises, (i) preparing graphene oxide solution by using improved Hummers method, then drying the graphene oxide solution and cutting into pieces, and grinding and sieving to obtain graphene oxide powder, (ii) (a) adding the graphene oxide powder into deionized water, and ultrasonic dispersing to obtain graphene oxide solution, (b) mixing the graphene oxide solution, ethylenediamine and sodium borate solution, and ultrasonic dispersing to obtain mixture, (c) placing the mixture into a high-pressure hydrothermal kettle lined with polytetrafluoroethylene, then heating high-pressure hydrothermal kettle lined with polytetrafluoroethylene, and naturally cooling to room temperature to obtain reaction product I, pouring the reaction product I into aqueous ethanol solution for dialysis to obtain dialyzed reaction product I, where the reaction product I is cylinder with diameter of 0.8-1 cm and height of 0.3-0.5 cm, (d) pre-freezing the reaction product I obtained in step (c), and naturally drying at room temperature to obtain nitrogen-doped three-dimensional graphene aerogel with high elasticity, and (iii) (a) placing the high-elastic nitrogen-doped three-dimensional graphene aerogel into the high-pressure hydrothermal kettle lined with polytetrafluoroethylene, and adding potassium permanganate solution, then immersing the high-elastic nitrogen-doped three-dimensional graphene aerogel in the potassium permanganate solution, and heat-treating the high-pressure hydrothermal kettle lined with polytetrafluoroethylene, and then naturally cooling to room temperature to obtain the reaction product II, and (b) washing the reaction product II with deionized water, then soaking in anhydrous ethanol, and drying in oven to obtain final product. An INDEPENDENT CLAIM is also included for nitrogen-doped three-dimensional graphene-supported manganese(IV) oxide catalyst prepared by above method.