▎ 摘　　要

NOVELTY - Preparing zinc oxide quantum dot/graphene oxide composite material involves mixing natural graphite powder, 98% concentrated sulfuric acid, phosphorus pentoxide and potassium disulfide, adding into closed reaction vessel and stirring at 60-100 degrees C for 4-6 hours. The pressure of reaction mixture is reduced. The natural graphite powder is washed to neutral and dried at room temperature for 18-36 hours to obtain preoxidized graphite sample. The preoxidized graphite sample is uniformly dispersed in 98% concentrated sulfuric acid. USE - Method for preparing zinc oxide quantum dot/graphene oxide composite material (claimed). ADVANTAGE - The method enables to prepare zinc oxide quantum dot/graphene oxide composite material in simple, eco-friendly and cost effective manner which consumes low energy. It has strong interaction and better potential for gas detection, and is protected from explosive, flammable and toxic and harmful environment. DETAILED DESCRIPTION - Preparing zinc oxide quantum dot/graphene oxide composite material involves mixing natural graphite powder, 98% concentrated sulfuric acid, phosphorus pentoxide and potassium disulfide, adding into closed reaction vessel and stirring at 60-100 degrees C for 4-6 hours. The pressure of reaction mixture is reduced. The natural graphite powder is washed to neutral and dried at room temperature for 18-36 hours to obtain preoxidized graphite sample. The preoxidized graphite sample is uniformly dispersed in 98% concentrated sulfuric acid. The potassium permanganate and deionized water are added under acidic conditions and stirred for 1-4 hours. The reaction mixture is diluted and hydrogen peroxide is added and stirred for 5-20 minutes. The reaction mixture is allow to stand for overnight to obtain precipitate. The precipitate is washed with hydrochloric acid and deionized water at rotation speed of 4500-6000 revolutions per minute for 3-8 minutes. The pH of supernatant is adjusted to 4-7 to obtain centrifuged product. The centrifuged product is undergo dialysis for 1-3 weeks in dialysis bag and treated for 3-5 hours to obtain aqueous solution of graphite. The aqueous solution of graphite is dried at 40-60 degrees C for 36-72 hours to obtain graphene oxide. The 0.01-0.04 pts. wt. graphene oxide is added into three-necked flask and mixed with 20-30 wt.% methanol solution at 30-50 degrees C in thermostatic water bath. the reaction mixture is added into three-necked flask with filling speed of 0.1-0.3 milliliter/minute. The 1-5 pts. wt. anhydrous zinc acetate alcohol solution having concentration of 10-30 millimolar is added. The 40-60 millimolar 0.5-2.5 pts. wt. aqueous solution of hexamethylammonium tetrachloride is added and reacted for 4-16 hours. The mixture solution is centrifuged, washed, filtered and dried to obtain desired product.