▎ 摘　　要

NOVELTY - Method for preparing graphene/titanium dioxide photocatalytic nanocrystals involves (a) adding graphite powder and sodium nitrate to a flask, adding concentrated sulfuric acid, dispersing, sealing the flask, placing the flask in an ice bath and stirring, (b) adding potassium permanganate to the flask, stirring, dripping ultrapure water, placing the flask in a water bath, reacting, adjusting the temperature of the water bath and continuously reacting, and (c) dripping hydrogen peroxide to the flask, reacting in a water bath, centrifuging with hydrochloric acid and washing with pure water. USE - Method is useful for preparing graphene/titanium dioxide photocatalytic nanocrystals, which are useful for the photocatalytic degradation of organic dyes and for the production of conductive battery (all claimed). ADVANTAGE - The method enables easy, safe and reliable preparation of graphene/titanium dioxide photocatalytic nanocrystals without high-pressure reaction, and precisely controls the titanium dioxide nanocrystals grown on graphene, thus avoiding the homogeneous nucleation phenomenon of titanium dioxide in the liquid phase. DETAILED DESCRIPTION - Method for preparing graphene/titanium dioxide photocatalytic nanocrystals involves (a) adding graphite powder and sodium nitrate to a flask, adding concentrated sulfuric acid, ultrasonically dispersing for 10-30 minutes, sealing the flask, placing the flask in an ice bath and stirring, (b) slowly adding potassium permanganate to the flask, stirring for 8-15 hours in an ice bath, slowly dripping ultrapure water, placing the flask in a water bath, reacting at 50 degrees C for 8-15 hours, adjusting the temperature of the water bath to 35 degrees C and continuously reacting for 12 hours, (c) dripping hydrogen peroxide to the flask, continuously reacting at 35 degrees C in a water bath for 3 hours, centrifuging with hydrochloric acid at high speed, washing with pure water and ethanol until the pH value of the mixture to be neutral and ultrasonically dispersing for 3 hours to obtain graphene oxide ethanol solution, (d) diluting the graphene oxide ethanol solution, slowly adding tetrabutyl titanate under vigorous stirring condition, ultrasonically dispersing for 30 minutes, dripping adding concentrated aqueous ammonia, stirring for 24 hours and carrying out high-speed centrifugal separation, and (e) drying the product in a blast oven, calcining the resulting product in a tubular furnace under inert gas atmosphere for 2 hours and naturally cooling to obtain graphene/titanium dioxide photocatalytic nanocrystals.