▎ 摘　　要

NOVELTY - Preparing thin film involves mixing graphene in mixture containing butanol, propylene glycol and citric acid. The obtained mixture is treated by ultrasonic vibrations for 30 minutes. The obtained graphene is soaked in deionized water for 60-120 minutes at 5-10 degrees C under helium environment. The obtained graphene is washed (4-8 times) with ethanol, and then dried. The 0.1-0.2mol/L zinc molybdate solution, 0.2-0.4mol/L bismuth vanadate solution and acetic acid are mixed to obtain mixed solution. The dried graphene is immersed in mixed solution for 12-48 hours. USE - Method for preparing thin film (claimed). ADVANTAGE - The method enables to prepare thin film that has high adsorption capacity, processing efficiency, and absorbing rate. DETAILED DESCRIPTION - Preparing thin film involves mixing graphene in mixture containing butanol, propylene glycol and citric acid. The obtained mixture is treated by ultrasonic vibrations for 30 minutes. The obtained graphene is soaked in deionized water for 60-120 minutes at 5-10 degrees C under helium environment. The obtained graphene is washed (4-8 times) with ethanol, and then dried. The 0.1-0.2mol/L zinc molybdate solution, 0.2-0.4mol/L bismuth vanadate solution and acetic acid are mixed to obtain mixed solution. The dried graphene is immersed in mixed solution for 12-48 hours. The obtained graphene is heated in muffle furnace at 400-450 degrees C for 2-4 hours, where heating rate is 5-8 degrees C/minute. The heated graphene is cooled to room temperature bismuth and zinc loaded graphene film. The obtained bismuth and zinc loaded graphene film is immersed in mixture containing propylene glycol monomethyl ether acetate, ethyl lactate, methyl isobutyl ketone, n-butyl aldehyde, N-methylpyrrolidone, N-isopropyl-N'-phenyl-p-phenylenediamine, glycerol and polyvinyl alcohol for 2-4 hours. The soaked film is removed, and then dried at room temperature. The dried film is heated in muffle furnace at 400-450 degrees C for 2-4 hours, where heating rate is 5-8 degrees C/minute, and then cooled to room temperature to obtain surface-modified thin film.