▎ 摘　　要

NOVELTY - Natural flake graphite and oxidant are added into acidic solution, mixed, and stirred. The resulting mixture is heated, deionized water is added, and stirred. Hydrogen peroxide is dropped to resulting mixture, stirred, and layers are separated. The resulting product is washed, and ultrasonic treatment is carried out, to obtain colloidal suspension of graphene oxide. The alkaline solution is added into colloidal suspension, and compound containing ferrous ion is added. The resulting mixture is stirred, solids are separated, washed, and dried to obtain graphene. USE - Preparation of graphene. ADVANTAGE - The method efficiently and economically provides graphene with high safety, and without environmental pollution. DETAILED DESCRIPTION - Natural flake graphite or highly-oriented pyrolytic graphite powder and strong oxidant are added into strong acidic solution, mixed uniformly, and stirred. The resulting mixture is heated at 35-45 degrees C, deionized water is added, stirred for 1-3 hours and heated at 80-100 degrees C for 1 hour. Hydrogen peroxide is dropped to the resulting mixture, stirring is stopped after completing the reaction, allowed to stand, layers are separated and lower colloidal suspension of graphene oxide is pickled. The resulting product is washed, till the impurities are removed and ultrasonic treatment is carried out, to obtain colloidal suspension of graphene oxide. The alkaline solution is added into colloidal suspension of graphene oxide, stirred, pH value of 10-13 is adjusted, and compound containing ferrous ion is added under protection of inert gases. The resulting mixture is stirred at (-10)-50 degrees C, solid-liquid separation is carried out after finishing the reaction, separated solids are washed with dilute hydrochloric acid and deionized water, and dried to obtain graphene.