▎ 摘　　要

NOVELTY - Natural crystalline flaky graphite and sodium nitrate are stirred with sulfuric acid. Potassium permanganate and deionized water are added and heated. Hydrogen peroxide is added and stirred, ultrasonically treated, vacuum-filtered, and washed. The solution is dried to obtain graphene oxide. Graphene oxide is placed in a quartz boat, the quartz boat is placed in a tubular furnace, inert gas is introduced, and the material is heated. Supply of inert gas is stopped, hydrogen is supplied and reduction reaction is carried out to obtain graphene powder. USE - Hydrogen-reduction preparation of graphene (claimed). ADVANTAGE - The method enables convenient, simple and feasible industrial preparation of high-purity graphene on a large scale. DETAILED DESCRIPTION - 0.1-2 g Natural crystalline flaky graphite and 0.1-2 g sodium nitrate are added to 50-100 ml 98 %mass sulfuric acid at 5-20 degrees C and fully stirred. 2-20 g Potassium permanganate is added in an amount of 0.4-4 g at an interval of 10-20 minutes and stirred for 2-4 hours. 150-500 ml Deionized water is added and heated to 80-95 degrees C. 10-100 ml 20-35% Hydrogen peroxide is added and stirred for 10-30 minutes, ultrasonically treated for 20-60 minutes, vacuum-filtered, and washed with 2-10 %mass hydrochloric acid and deionized water until there is no sulfate ion and the solution pH is 7. The solution is dried at 60-120 degrees C for 10-40 hours to obtain graphene oxide. 0.1-2 g Graphene oxide is placed in a quartz boat, the quartz boat is placed in a tubular furnace, inert gas is introduced, and the material is heated to 300-800 degrees C. Supply of inert gas is stopped, hydrogen is supplied as reducing gas at 0.01-0.1 MPa and 100-500 mL/minute, and reduction reaction is carried out for 1-4 hours. Heating is stopped, hydrogen supply is stopped, inert gas is supplied for 1-2 hours, and the product is naturally cooled to room temperature to obtain graphene powder.