▎ 摘　　要

NOVELTY - Preparing a bismuth oxyiodide/graphene oxide visible light photocatalyst by a low-temperature liquid phase precipitation method involves: (a) weighing bismuth(III)nitrate pentahydrate and organic acid, dissolving in a mixed solution of an alcohol solvent and deionized water, then adding 5 mg/ml graphene oxide aqueous dispersion, stirring, finally adding 10 %mass potassium iodide solution, stirring and reacting at 25-45 degrees C for 1-5 hours, adjusting the pH value of the reaction system to 2-7 with a sodium hydroxide solution having a mass concentration of 10% during the reaction, centrifuging the product after the reaction is completed, washing 3-5 times with deionized water and absolute ethanol, respectively, carrying out centrifugal separation, drying and grinding to obtain bismuth oxyiodide/graphene oxide visible light photocatalyst, where the mass ratio of bismuth(III)nitrate pentahydrate, graphene oxide, alcohol solvent and deionized water is (1-10):(0.01-0.5):(25-50):(25-50). USE - The method is useful for preparing a bismuth oxyiodide/graphene oxide visible light photocatalyst, by a low-temperature liquid phase precipitation method, which is useful in photocatalytic degradation of dye including methyl orange, methylene blue, crystal violet and rhodamine B (claimed). ADVANTAGE - The method: is simple in preparation; does not require polymer or surfactant to-be-added; controls the structure and morphology of bismuth oxyiodide by coordination and complexation of organic acids with bismuth ions and the action of graphene oxide pi cations; and uses the high specific surface area of the graphene oxide to improve the adsorption performance and the good conductivity of the photocatalyst on the dye and to promote the separation of the photogenerated electrons and holes of the photocatalyst, thus realizing the synergistic effect of the adsorption enrichment and the photocatalytic degradation of the dye. DETAILED DESCRIPTION - Preparing a bismuth oxyiodide/graphene oxide visible light photocatalyst by a low-temperature liquid phase precipitation method involves: (a) weighing bismuth(III)nitrate pentahydrate and organic acid, dissolving in a mixed solution of an alcohol solvent and deionized water, then adding 5 mg/ml graphene oxide aqueous dispersion, stirring at 25 degrees C for 0.5-1.5 hours, finally adding 10 %mass potassium iodide solution, stirring and reacting at 25-45 degrees C for 1-5 hours, adjusting the pH value of the reaction system to 2-7 with a sodium hydroxide solution having a mass concentration of 10% during the reaction, centrifuging the product after the reaction is completed, washing 3-5 times with deionized water and absolute ethanol, respectively, carrying out centrifugal separation, drying and grinding to obtain bismuth oxyiodide/graphene oxide visible light photocatalyst, where the mass ratio of bismuth(III)nitrate pentahydrate, graphene oxide, alcohol solvent and deionized water is (1-10):(0.01-0.5):(25-50):(25-50), and the molar ratio of bismuth(III)nitrate pentahydrate, organic acid and potassium iodide is 1:(0.5-1.5):(0.5-1.5); and (b) when white LED lamp is irradiated for 70-90 minutes, basically balancing the photocatalytic degradation of the bismuth oxyiodide/graphene oxide photocatalyst on the dye solution, and when the white LED light is irradiated for 90 minutes, reaching the photocatalytic dye degradation rates of the bismuth oxyiodide/graphene oxide photocatalyst for 10-50 mg/l dye solutions to be 78-97.88% and 37-49.55%, respectively, where the photocatalytic dye degradation rate of the bismuth oxyiodide/graphene oxide photocatalyst after five times of cyclic utilization is 75-88% of the degradation rate of the first photocatalytic dye.