▎ 摘　　要

NOVELTY - Preparing bismuth oxide/nitrogen-doped graphene composite photocatalyst comprises e.g. using graphite powder as raw material, preparing graphene oxide by Hume method, filtering and washing graphene oxide by deionized water and ethanol for many times, taking deionized water as solvent to obtain graphene oxide suspension, mixing and stirring graphene oxide suspension and urea, drying, and grinding to obtain mixed solid powder of graphene oxide and urea, annealing the mixed solid powder, obtaining nitrogen-doped graphene, adding potassium iodide-ethanediol solution, and ultrasonically dispersing. USE - The composite photocatalyst is useful for photocatalytic degradation of organic pollutants. ADVANTAGE - The composite photocatalyst has potential application value in the field of photocatalytic sewage treatment. DETAILED DESCRIPTION - Preparing bismuth oxide/nitrogen-doped graphene composite photocatalyst comprises (i) using graphite powder as raw material, preparing graphene oxide by Hume method, filtering and washing graphene oxide by deionized water and ethanol for many times, taking deionized water as solvent to obtain graphene oxide suspension, mixing and stirring graphene oxide suspension and urea for more than 12 hours, where the mass ratio of graphene oxide and urea is 0.1:1, drying, and grinding to obtain mixed solid powder of graphene oxide and urea, annealing the mixed solid powder at 900-1100 degrees C in vacuum environment, and obtaining nitrogen-doped graphene, (ii) adding potassium iodide-ethanediol solution to the nitrogen-doped graphene, ultrasonically dispersing to obtain first solution, taking Bismuth nitrate pentahydrate and dissolving in ethanediol to obtain second solution, where the mass ratio of nitrogen-doped graphene and bismuth nitrate pentahydrate is 0.006-0.041:1, and the ratio of potassium iodide and bismuth nitrate pentahydrate is 1:1, mixing the first solution and second solution, and stirring to obtain mixed solution, and (iii) placing the resulting mixed solution in a high-pressure reaction kettle, reacting at 140-180 degrees C for 8-15 hours, under hydro-thermal reaction condition, completing crystallization and complexing nitrogen-doped graphene and bismuth iodide to obtain composite solid product of nitrogen-doped graphene and bismuth iodide, dispersing the hydro-thermal reaction solid product in deionized water, centrifuging, dispersing in ethanol, washing for many times, and drying.