▎ 摘　　要

NOVELTY - Preparing needle-shaped manganese dioxide/graphene oxide composite nano material comprises e.g. taking graphite powder in eggplant flask, under magnetic stirring, adding concentrated sulfuric acid, stirring uniformly, obtaining mixed solution A, under ice bath condition, adding potassium permanganate into the mixed liquid A at lower than 5 degrees C within 1-4 hours to obtain mixed solution B, subjecting the mixed solution B for hydrothermal reaction under 15-55 degrees C water bath stirring for 1-5 hours, adding lye to obtain mixed liquid C, cooling under ice bath condition, and adding de-ionized water. USE - The method is useful for preparing needle-shaped manganese dioxide/graphene oxide composite nano material (claimed). ADVANTAGE - The method is simple and economical. The needle-shaped manganese dioxide is nano grade, having 10-300 nm long and 3-30 nm wide. DETAILED DESCRIPTION - Preparing needle-shaped manganese dioxide/graphene oxide composite nano material comprises taking graphite powder in eggplant flask, under magnetic stirring, adding concentrated sulfuric acid, stirring uniformly, obtaining mixed solution A, where the mass ratio of the concentrated sulfuric acid and graphite powder is (50-100):1, under ice bath condition, adding potassium permanganate into the mixed liquid A at lower than 5 degrees C within 1-4 hours to obtain mixed solution B, where potassium permanganate and the graphite powder mixed liquid mass ratio is (3-20):1, subjecting the mixed solution B for hydrothermal reaction under 15-55 degrees C water bath stirring for 1-5 hours, adding lye to obtain mixed liquid C, cooling the mixed liquid C under ice bath condition, adding de-ionized water to obtain mixed liquid D, where the deionized water and graphite powder mass ratio is (100-300):1, allowing to stand the mixed liquid D for 8-14 hours, pouring the supernatant, centrifugal separating at 11000-13000 revolutions/minute, after separating, adding water to wash, to obtain mixed liquid E, subjecting mixed liquid E to dialysis using dialysis membrane until the pH value 6, rotating and evaporating to dry, grinding to uniform powder, and rotary evaporating to obtain needle shape manganese dioxide/graphene oxide composite nano material.