▎ 摘　　要

NOVELTY - Synthesis of nitrogen-doped titanium oxide-bismuth oxyiodide-reduced graphene oxide-based ternary photocatalytic composite material by a hydrothermal method, involves adding graphene oxide to deionized water and ultrasonically processing to obtain a graphene oxide suspension, adding nitrogen-doped titanium oxide powder to graphene oxide suspension and ultrasonically processing, adding bismuth(III) nitrate pentahydrate under stirring conditions, adding potassium iodide and stirring uniformly to obtain a mixture, placing the obtained mixture in a polytetrafluoroethylene reactor for hydrothermal reaction, naturally cooling to room temperature, sequentially washing the obtained reaction product with anhydrous ethanol and deionized water, drying and obtaining composite material, in which mass ratio of nitrogen-doped titanium oxide to bismuth oxyiodide is 1:1 and mass ratio of reduced graphene oxide to bismuth oxyiodide is (1-2):1. USE - Synthesis of nitrogen-doped titanium oxide-bismuth oxyiodide-reduced graphene oxide-based ternary photocatalytic composite material used for degrading methylene blue in wastewater (claimed). ADVANTAGE - The method enables synthesis of ternary photocatalytic composite material with improved methylene blue degradation rate of more than 99% under the condition of low energy consumption and visible light. DETAILED DESCRIPTION - Synthesis of nitrogen-doped titanium oxide-bismuth oxyiodide-reduced graphene oxide-based ternary photocatalytic composite material by a hydrothermal method, involves (i) preparing nitrogen-doped titanium oxide by adding tetrabutyl titanate to anhydrous ethanol in a volume ratio of 8:40-50 to obtain a tetrabutyl titanate-ethanol solution, dissolving urea in absolute ethanol in a mass ratio of 0.7 g:(40-50) mL, adding 36-38% hydrochloric acid solution and deionized water to obtain a urea-hydrochloric acid-ethanol aqueous solution, dripping urea-hydrochloric acid-ethanol aqueous solution to the tetrabutyl titanate-ethanol solution, stirring for 30-40 minutes to obtain a mixed solution, in which the molar ratio of titanium element with respect to nitrogen element in the mixed solution is 1:1, transferring the mixed solution to a polytetrafluoroethylene reactor for hydrothermal reaction, naturally cooling to room temperature, sequentially washing the obtained reaction product is with anhydrous ethanol and deionized water, drying to obtain a solid product, calcining the solid product and obtaining nitrogen-doped titanium oxide powder, and (ii) adding graphene oxide to deionized water and ultrasonically processing to obtain a graphene oxide suspension, adding nitrogen-doped titanium oxide powder to graphene oxide suspension and ultrasonically processing, adding bismuth(III) nitrate pentahydrate under stirring conditions, adding potassium iodide and stirring uniformly to obtain a mixture, placing the obtained mixture in a polytetrafluoroethylene reactor for hydrothermal reaction, naturally cooling to room temperature, sequentially washing the obtained reaction product with anhydrous ethanol and deionized water, drying and obtaining composite material, in which mass ratio of nitrogen-doped titanium oxide to bismuth oxyiodide is 1:1 and mass ratio of reduced graphene oxide to bismuth oxyiodide is (1-2):1. An INDEPENDENT CLAIM is included for use of ternary photocatalytic composite material for degradation of methylene blue by adding ternary photocatalytic composite material to methylene blue-containing wastewater in a mass ratio of (80-100):1, stirring in the dark room until the adsorption-desorption equilibrium, and degrading under irradiation of an LED lamp at a power of 18 W for a degradation time of 30-60 minutes.