▎ 摘　　要

NOVELTY - Preparation of graphene film includes mixing graphite flake, sodium nitrate and concentrated sulfuric acid, adding potassium permanganate, ice water bath stirring, adding distilled water, adding hydrogen peroxide, and washing with distilled water to obtain graphene oxide slurry; sanding metal piece with sandpaper, and placing to distilled water to obtain treated metal piece; adding graphene oxide slurry with distilled water, ultrasonically dispersing, adding treated metal piece, oil bath reacting , washing off with distilled water and absolute ethanol, sonicating in absolute ethanol, and taking out metal piece to obtain metal oxide/reduced graphene oxide composite solution; and adding to hydrochloric acid solution, stirring, washing with distilled water, centrifuging, dispersing in organic solvent to obtain reduced graphene oxide solution, placing substrate to beaker, adding distilled water, dropping reduced graphene oxide solution, slowly suctioning out excess water, and oven-drying. USE - Method for preparation of graphene film. ADVANTAGE - The method is simple, and has direct self-assembly of reduced graphene oxide, mild reaction condition, and reduced damage to substrate. DETAILED DESCRIPTION - Preparation of graphene film comprises: (A) mixing graphite flake, sodium nitrate and concentrated sulfuric acid for 30 minutes to obtain first mixture, adding potassium permanganate, ice water bath stirring for 12 hours, adding distilled water for 12 hours, adding hydrogen peroxide for 24 hours, and washing with distilled water for 5-6 times to obtain graphene oxide slurry; (B) sanding metal piece with sandpaper, and placing to distilled water for 5 minutes to obtain treated metal piece; (C) adding graphene oxide slurry with distilled water, ultrasonically dispersing, adding treated metal piece, oil bath reacting at 25 degrees C for 12 hours, washing off unreacted graphene oxide adsorbed on the surface of metal sheet with distilled water and absolute ethanol, sonicating in absolute ethanol for 5 minutes, and taking out metal piece to obtain metal oxide/reduced graphene oxide composite solution; and (D) adding to hydrochloric acid solution, stirring for 2 hours, washing with distilled water, centrifuging, dispersing in organic solvent to obtain reduced graphene oxide solution, placing substrate to beaker, adding distilled water, dropping reduced graphene oxide solution, and slowly suctioning out excess water using straw until liquid level drops below the substrate, and oven-drying.