▎ 摘　　要

NOVELTY - Preparation of a graphene, involves: 1) adding graphite powder and sodium nitrate at 5 degrees C in reaction container, then adding concentrated sulfuric acid, ultrasonic treating, stirring; adding in the mixture, potassium permanganate solution; adding in formed graphite suspension, dilute sulfuric acid, ultrasonic treating; adding deionized water, maintain reaction system at not greater than 10 degrees C; 5) dripping hydrogen peroxide solution; 6) adding hydrochloric acid, centrifugal washing; adding formed graphene oxide dispersion liquid in oxalic acid powder, and then heating. USE - For preparation of a graphene (claimed). ADVANTAGE - The method combines physical and chemical methods; improves the degree of peeling intercalation of graphite oxide; improves the production efficiency of graphene oxide than the prior art; increases 25-30% yield; enables the preparation of high yields of high-quality graphene; is simple process; provides excellent product performance characteristics; and is suitable for mass production of multilayer graphene. DETAILED DESCRIPTION - Preparation of a graphene, involves: 1) adding graphite powder and sodium nitrate at 5 degrees C in reaction container, then adding concentrated sulfuric acid, maintaining reaction system at 5 degrees C, ultrasonic treating, then completely stirring; 2) adding in mixture of step 1), potassium permanganate solution, maintaining reaction system at not greater than 10 degrees C, stirring for 16-24 hours to prepare a graphite suspension; 3) adding in graphite suspension, dilute sulfuric acid, carrying out ultrasonic treatment, then under stirring, fully reacting for 2-6 hours; 4) adding deionized water, maintain reaction system at not greater than 10 degrees C, fully reacting for 6-12 hours; 5) maintaining reaction system temperature condition at not greater than 10 degrees C, dripping hydrogen peroxide solution until gas is escaping; 6) adding hydrochloric acid, fully reacting, and then centrifugal washing the reaction product with deionized water, until the pH of the upper clear liquid of the last centrifugation is 6.5-7.5; 7) placing step 6) residue in deionized water ultrasonic dispersion, centrifuging upper layer solution to obtain the graphene oxide dispersion liquid; and 8) adding graphene oxide dispersion liquid in oxalic acid powder, and then heating under stirring and constant temperature reaction to remove oxalic acid to obtain uniform dispersion of the graphene solution.