▎ 摘　　要

NOVELTY - Preparing graphene-titanium dioxide nanotube/fluorine-doped tin oxide double composite film comprises e.g. (i) adding graphene oxide into deionized water, then adding graphene oxide into deionized water, adding titanium dioxide, (ii) adding sodium hydroxide into the solution of step (i), (iii) washing to obtain graphene-titanium dioxide nanotube composite powder, performing hydrothermal reaction, and (iv) adding graphene-titanium dioxide nanotube composite powder into polyvinyl alcohol aqueous solution. USE - The method is useful for preparing graphene-titanium dioxide nanotube/fluorine-doped tin oxide double composite film (claimed). ADVANTAGE - The composite film increase specific surface area of titanium dioxide nanotube, improve adsorption, inhibits photo-generated electron-hole recombination, and enhances photocatalytic efficiency of titanium dioxide. DETAILED DESCRIPTION - Preparing graphene-titanium dioxide nanotube/fluorine-doped tin oxide double composite film comprises (i) adding 0.18-5.46 mg graphene oxide into per milliliter of deionized water, then adding graphene oxide into 55 ml deionized water, performing ultrasound treatment using ultrasonic cleaning instrument for 30-60 minutes so that graphene evenly dispersed, where mass ratio between graphene and titanium dioxide powder is 0.01-0.3:1, adding titanium dioxide, continue ultrasound treatment for 30-60 minutes so that titanium dioxide and graphene oxide evenly divided, scattered and anchored together, (ii) adding sodium hydroxide into the solution of step (i) so that the solution concentration of 1-10 mol/l, stirring and then transferring into 100 ml polytetrafluoroethylene lined reactor, insulating at 110-180 degrees C for 12-48 hours, (iii) heating to room temperature, washing resulting precipitate with 0.1-1 mol/l hydrochloric acid to pH between 2-3 and then stirring at room temperature for 12 hours, then washing precipitate with deionized water to neutral, drying at 60 degrees C and then heat-treating at 300-500 degrees C for 1 hour to obtain graphene-titanium dioxide nanotube composite powder, performing hydrothermal reaction to obtain titanium dioxide nanotubes which is in amorphous form, where heat treatment is carried out by crystallizing amorphous titanium dioxide nanotubes to form anatase titanium dioxide nanotubes, and (iv) adding graphene-titanium dioxide nanotube composite powder into polyvinyl alcohol aqueous solution having mass fraction of 0.5-2%, then adding graphene-titanium dioxide nanotube composite powder into per liter of aqueous solution of polyvinyl alcohol in a ratio of 1-5 g to obtain dispersion of a graphene- titanium dioxide nanotube composite powder, spraying film into the way, depositing dispersion of the graphene-titanium dioxide nanotube composite powder onto fluorine-doped tin oxide glass having substrate temperature of 100-300 degrees C to obtain final product.