▎ 摘　　要

NOVELTY - Preparation of high-conductivity graphene film involves (s1) slowly adding crystalline flake graphite in concentrated sulfuric acid, slowly dripping 15% hydrogen peroxide aqueous solution, carrying out heat-preserving, filtering to obtain graphite oxide, and adding deionized water to obtain 1-1.5% graphite oxide suspension, (s2) adding suspension in homogenizer, stirring for 30 minutes at 5000 rpm to prepare a dispersion liquid, performing vacuum suction filtration, washing with deionized water to form a filter membrane, taking a polyethylene terephthalate membrane as a substrate, dripping isopropanol on the surface of the substrate, slowly dripping acetone on surface of the filter membrane, cleaning with absolute ethyl alcohol and acetone for three times, and drying to prepare the large-diameter graphene oxide film, and (s3), transferring film to surface of a quartz substrate, placing in furnace, introducing the mixed solution in vaporizing furnace, heating, and calcining. USE - Preparation of high-conductivity graphene film (claimed) used in electronic devices such as liquid crystal displays, organic light emitting diodes (OLEDs), touch screens, and photovoltaics. ADVANTAGE - The method enables to prepare high-conductivity graphene film, which has improved conductive performance. DETAILED DESCRIPTION - Preparation of high-conductivity graphene film involves (s1) slowly adding crystalline flake graphite in 70 %mass concentrated sulfuric acid, uniformly stirring in ice-water bath for 30 minutes, adding potassium permanganate, heating to 35℃, uniformly stirring for 4 hours, slowly dripping 15% hydrogen peroxide aqueous solution after stirring, heating to 65-90℃, carrying out heat-preserving until no gas is generated, dripping a 5% dilute hydrochloric acid, continuously stirring and reacting for 2 hours, dialyzing with deionized water to neutrality after the reaction is finished, filtering to obtain graphite oxide, and adding deionized water to obtain 1-1.5% graphite oxide suspension, (s2) adding the graphene oxide suspension in homogenizer, stirring for 30 minutes at 5000 rpm to prepare a dispersion liquid, performing vacuum suction filtration by fiber-mixed microporous filter membrane of 0.55 µm, washing with deionized water to form a filter membrane with a thin film on one surface, taking a polyethylene terephthalate membrane as a substrate, dripping isopropanol on the surface of the substrate, attaching the surface of the membrane to the surface of a substrate, continuously dripping isopropanol, discharging bubbles between the filter membrane and substrate, placing the membrane in a culture dish, slowly dripping acetone on the surface of the filter membrane until the filter membrane is dissolved, leaving still for 1 hours, discharging the acetone, obliquely placing the substrate, respectively cleaning with absolute ethyl alcohol and acetone for three times, and drying to prepare the large-diameter graphene oxide film, and (s3), transferring the large-diameter graphene oxide film to the surface of a quartz substrate, placing the large-diameter graphene oxide film in a high-temperature reaction furnace, preheating to 300℃, arranging a vaporizing furnace in the front of the high-temperature reaction furnace, introducing the mixed solution in vaporizing furnace for vaporization, introducing the vaporized solution in high-temperature reaction furnace along with argon gas flow, reacting for 30 minutes, heating to 600℃, and calcining for 2 hours.