▎ 摘　　要

NOVELTY - The method for preparing titanium dioxide photocatalyst involves mixing uniformly flake graphite, concentrated sulfuric acid and phosphoric acid, adding potassium permanganate, adding deionized water and hydrogen peroxide, adding hydrochloric acid and anhydrous ethanol, dispersing graphene oxide in N,N-dimethylformamide solution, adding thionyl chloride, adding boric acid to aqueous dispersion of aminated graphene oxide, introducing inert gas or nitrogen, calcining at to obtain titanium dioxide/amidoized graphene composite photocatalyst. USE - Method for preparing titanium dioxide photocatalyst for processing hexavalent chromium ion. ADVANTAGE - The method enables preparation of titanium dioxide photocatalyst with excellent photocatalytic activity. DETAILED DESCRIPTION - Method for preparing titanium dioxide photocatalyst involves adopting titanium dioxide/amidoized graphene composite photocatalyst. The content of aminated graphene oxide is 0.5-3 wt.%. The titanium dioxide/amidoized graphene composite photocatalyst is prepared by mixing uniformly 2-5 pts. wt. flake graphite, 300-500 pts. wt. concentrated sulfuric acid and 30-60 pts. wt. phosphoric acid, slowly adding 15-20 pts. wt. potassium permanganate, stirring at 45-55 degrees C for 9-18 hours, adding 300-500 pts. wt. deionized water at 0-5 degrees C, adding 10-30% concentration of 20-50 pts. wt. hydrogen peroxide, stirring for 5-10 minutes, successively treating with deionized water, adding 10-30 wt.% hydrochloric acid and anhydrous ethanol, vacuum drying to obtain graphene oxide, dispersing graphene oxide in 15-20 pts. wt. N,N-dimethylformamide solution, adding 40-60 pts. wt. thionyl chloride at 0-5 degrees C, mixing evenly, heating at 65-80 degrees C, continuously stirring for 30-40 hours, cooling to room temperature, filtering to obtain aminated graphene oxide, adding boric acid to aqueous dispersion of aminated graphene oxide, heating at 50-70 degrees C, leaving still for 90-180 minutes, cooling to room temperature to obtain suspension, pumping suspension, washing and drying in vacuum to obtain light brown powder, introducing inert gas or nitrogen, calcining at 200-400 degrees C to obtain titanium dioxide/amidoized graphene composite photocatalyst. The ratio of aminated graphene, boric acid and ammonium hexafluorotitanate is 1:(20-50):(20-50).