▎ 摘　　要

NOVELTY - Preparing graphene-titanium dioxide composite photo-catalyst involves mixing 300-500 mg graphite powder and 1.8-2.0 g sodium nitrate in mixture, adding 18-20 mL of 98% concentrated sulfuric acid and stirring for 1-1.5 hours. The 2.0-3.0 g potassium permanganate powder is added into reactor, stirred and reacted at temperature lower than 5 degrees C for 1.5-2.0 hours. The reaction system temperature is reduced to 35-40 degrees C for 1-1.5 hours. The 40-50 mL deionized water is added to reaction system, heated at 90-100 degrees C for 10-15 minutes and cooled reaction product to room temperature. The 70-100 mL de-ionized water is added to dilute and 10-15 mL of 35% hydrogen peroxide solution is added. The reaction product is filtered to obtain filter cake. The filter cake is washed three times with 300-400 ml of 5% hydrochloric acid. The de-ionized water is used to wash three times. The filter cake is kept for two days for dialysis, dried in vacuum for 24 hours at 60 degrees C and grinded to obtain graphene oxide. USE - Method for preparing graphene-titanium dioxide composite photo-catalyst. ADVANTAGE - The method enables to prepare graphene-titanium dioxide composite photo-catalyst that has convenient operation, and in simple, eco-friendly and cost effective manner. DETAILED DESCRIPTION - The oxidized graphene is added into de-ionized water in ultrasonic cleaner for ultrasonic treatment for 20-60 minutes to obtain 1 mg/mL oxidized graphene dispersion liquid. The 5.8-6 mL hexadecyl trimethyl ammonium bromide is dissolved in 10 mL pentanol and 60 mL hexane to obtain hexadecyl trimethyl ammonium bromide suspending liquid under condition of continuously agitating. The 10-20 mL graphene oxide dispersion is added. The hexadecyltrimethyl ammonium bromide is added in suspension and stirred for half an hour. The 0.6-6 mL of 68% titanium solution is added, stirred for half an hour, poured into high-pressure reaction kettle and reacted for 3-12 hours at 180-200 degrees C. The reaction product is placed into rotary evaporator. The pentanol and normal hexane solvent is removed. The water and ethanol is used to wash for 2-3 times and dried for 1-2 hours at (-)80 degrees C to obtain graphene-titanium dioxide composite photo-catalyst.