▎ 摘　　要

NOVELTY - Preparing functionally modified graphene nanomaterials comprises mixing liquid nitrogen and graphite flakes in semi-sealed container and then heating, placing the mixture in oven and rapidly heating, adding sodium nitrate to mixture, adding concentrated sulfuric acid to mixture and stirring, cooling mixture, adding potassium permanganate to mixture, stirring obtained mixture to obtain a solution, heating solution, adding hydrogen peroxide to solution, stirring mixture and centrifuging, and adding hydrochloric acid solution to mixture and then washing with deionized water. USE - The method is useful for preparing functionally modified graphene nanomaterials (claimed). ADVANTAGE - The method is capable of easily preparing the functionally modified graphene nanomaterials with improved stability. DETAILED DESCRIPTION - Preparing functionally modified graphene nanomaterials comprises mixing liquid nitrogen and graphite flakes in a semi-sealed container and then heating for 0.1-0.5 hours, placing the mixture in an oven and then rapidly heating at 200-500 degrees C for 1-5 minutes, adding sodium nitrate to the mixture at a mass ratio of 1:2-4:1, adding concentrated sulfuric acid to the mixture and stirring using a magnetic stirrer, cooling the mixture for 30-120 minutes, adding potassium permanganate to the mixture at a mass ratio of 1:2-5:1, stirring the obtained mixture for 2-5 hours and then heating at 35-55 degrees C for 30-90 minutes, stirring the mixture to obtain a solution, heating the solution at 20-60 degrees C for 6-18 hours, adding hydrogen peroxide to the solution at a mass ratio of 1:4-1:30, stirring the mixture and centrifuging, adding 1.5 wt.% of hydrochloric acid solution to the mixture and then washing with deionized water, adjusting pH of the mixture to less than 5, freeze-drying the obtained product to obtain tanned product, drying the obtained product and then ultrasonicating for 30-90 minutes, reducing the dried product with hydrazine to obtain graphene sheet, adding functional modifier to the graphene sheet and then dissolving in deionized water, heating the obtained product at 50-90 degrees C and then stirring using a magnetic stirrer for 30-120 minutes, and subjecting the obtained product to suction filtration and then adding 0.5-5% of functional modifier.