▎ 摘　　要

NOVELTY - A graphene is prepared by mixing crystalline flake graphite, concentrated nitric acid, and potassium permanganate to obtain mixed acid solution, adding phosphoric acid, reacting at 85-95 degrees C for 1 hour, washing until pH is 4.5-5.5, drying at less than or equal to 100 degrees C, extruding at 550-900 degrees C for 30 s to 2 minutes, cooling at room temperature, adding aqueous sodium bicarbonate, stirring at 100-270 degrees C for 10 minutes to 3 hours, and drying under vacuum state for 12-24 hours. USE - Preparation of graphene (claimed). ADVANTAGE - Preparation process has greatly reduced process temperature.