▎ 摘　　要

NOVELTY - Preparation of manganese dioxide (MnO2) nanowire/graphene composite film includes adding crystalline flake graphite powder in sulfuric acid, adding sodium nitrate and potassium permanganate, and reacting; heating and washing; adding potassium permanganate, dissolving in water, adding hydrochloric acid, sealing, cooling, and washing; ultrasonically dispersing graphene oxide in water, dissolving, and mixing uniformly; vacuum filtering, and drying; and reducing the composite film into hydrazine hydrate solution, and vacuum drying to obtain the composite film. USE - Method for preparing MnO2 nanowire/graphene composite film (claimed). ADVANTAGE - The method improves composite film poor recycle stability and volume expansion effect. DETAILED DESCRIPTION - Preparation of MnO2 nanowire/graphene composite film comprises: (A) mechanically stirring under ice bath condition, adding crystalline flake graphite powder in 98% concentrated sulfuric acid, adding 50-80 wt.% sodium nitrate, and potassium permanganate which is 2-4 times weight of graphene, and reacting under ice bath for 30-120 minutes; (B) heating at 30-40 degrees C for 4-5 hours, adding deionized water and hydrogen peroxide, stirring for 1-3 hours, adding 5% concentration of hydrochloric acid, centrifugally washing until there is no sulfate ion to obtain oxidized graphene powder; (C) adding potassium permanganate, dissolving in deionized water, adding 30-40 wt.% hydrochloric acid, sealing under the condition of heating up to 110-140 degrees C for 10-24 hours, cooling to room temperature, and washing to obtain the MnO2 nanopowder; (D) ultrasonically dispersing graphene oxide in water, dissolving completely, according to the mass ratio of graphene oxide to MnO2 nanopowder of 1:(0.5-2), adding MnO2 nanopowder, and mixing uniformly; (E) vacuum filtering film, and drying at 75-90 degrees C to obtain self-supporting MnO2 nanowire/graphene oxide composite film; and (F) reducing the composite film into hydrazine hydrate solution, vacuum drying to obtain the self-supported MnO2 nanowire/graphene composite film.