▎ 摘　　要

NOVELTY - A graphene composite material preparing method involves preparing graphite oxide by performing low-temperature, intermediate-temperature and high-temperature subsection reactions on original graphite, and concentrated sulfuric acid with potassium permanganate to obtain graphite oxide, dispersing the graphite oxide in de-ionized water, reducing the prepared graphite oxide with hydrazine hydrate to obtain graphene oxide, and mixing graphene oxide with manganese(II) chloride tetrahydrate in isopropyl alcohol solution and potassium permanganate to obtain finished product. USE - Method for preparing graphene composite material. ADVANTAGE - The method enables preparing material with better commercialization, high purity and high stability without the need of dispersing agent and stabilizer in a simple, energy-saving and environment-friendly manner. DETAILED DESCRIPTION - A graphene composite material preparing method involves preparing graphite oxide by performing low-temperature, intermediate-temperature and high-temperature subsection reactions on original graphite and 98% concentrated sulfuric acid (20-35 mg/ml) at 4 degrees C for 10-30 minutes. The original graphite and potassium permanganate are mixed at mass ratio of 1:(4-6) and slowly mixed into the mixed solution, and the potassium and water are added and stirred for 90-120 minutes in ice bath followed by raising the temperature to 32-38 degrees C in a water bath, stirring for 30-60 minutes, raising the temperature to 57-63 degrees C for 20-40 minutes, slowly dropping de-ionized water in the mixed solution to make the mass concentration of the original graphite in the mixed solution reduced to 8-10 mg/ml, continuously stirring and reacting at 25-30 degrees C for 30-60 minutes, stirring the solution quickly adding de-ionized water, adding hydrogen peroxide into the mixed solution, continuously stirring for 30-60 minutes to obtain golden brown suspension with mass fraction 10% hydrochloric acid, and allowing for centrifugal washing to remove sulfate ion at 60-80 degrees C to obtain graphite oxide powder. The graphite oxide powder is dispersed in de-ionized water, ultrasonic treatment is performed for 0.5-2 hours to obtain the uniformly dispersed thickness of 0.5-1.5 mg/ml. The prepared graphite oxide is reduced with hydrazine hydrate, refluxed and reacted at 77-83 degrees C for 15 minutes to 24 hours, filtered, washed and ultrasonically dispersed to obtain uniform suspension and dried to obtain the graphene oxide by freezing. The graphene oxide (5-30 mg/ml) is mixed with manganese(II) chloride tetrahydrate in an isopropyl alcohol solution, and the mixture is reacted at 77-83 degrees C for 0.5-2 hours to obtain the uniform mixed solution. The mixed solution is added with potassium permanganate (25-35 mg/ml), refluxed and reacted for 20-40 minutes and filtered to obtain the composite of the graphene with the different oxidation degrees and the manganese dioxide through oxidation reduction.