▎ 摘　　要

NOVELTY - Preparing tin doped bismuth oxychloride/graphene composite photo catalyst comprises e.g. (i) dissolving bismuth(III) nitrate pentahydrate in hydrochloric acid solution to obtain solution X, (ii) dissolving tin(II) chloride dehydrate in hydrochloric acid solution, and then heating with stirring, (iii) adding the solution X into the solution Y, (iv) continuing for stirring the mixed solution, then suction filtering, washing and then drying, (v) dissolving oxidized graphene in water, then adding tin-doped bismuth oxychloride visible light catalyst, and post processing. USE - The method is useful for preparing tin doped bismuth oxychloride/graphene composite photo catalyst (claimed). ADVANTAGE - The catalyst has better light absorption performance, and also response to visible light under photocatalytic performance. DETAILED DESCRIPTION - Preparing tin doped bismuth oxychloride/graphene composite photo catalyst comprises (i) dissolving 1 mmol of bismuth(III) nitrate pentahydrate in 10 ml of 1 mol/l hydrochloric acid solution to obtain solution X, (ii) dissolving 1 mmol tin(II) chloride dehydrate in 40 ml molar concentration of 1 mol/l hydrochloric acid solution, and then heating with stirring to obtain clear solution Y, (iii) dropwise adding the solution X into the solution Y under stirring for 30 minutes, adjusting pH value of the mixed solution to 6 using 2 mol/l sodium hydroxide solution, (iv) continuing for stirring the pH adjusted the mixed solution for 2 hours, then suction filtering to collect precipitate, 3 times washing with water and ethanol, and then drying in a constant-temperature drying oven at 60 degrees C for 5 hours to obtain tin-doped bismuth oxychloride visible light catalyst, (v) ultrasonically dissolving 0.625-5 mg oxidized graphene in 50 ml water to obtain aqueous solution of graphene, then adding 1 g tin-doped bismuth oxychloride visible light catalyst, ultrasonic dispersing for 30 minutes, and then stirring for 2 hours, suction filtering to collect precipitate, 3 times washing with water and ethanol, and then drying in a constant-temperature drying oven at 60 degrees C for 5 hours to obtain final product.