▎ 摘　　要

NOVELTY - Preparing lanthanum-doped microspherical bismuth oxybromide (BiOBr)-graphene composite material comprises (i) adding ethylene glycol, bismuth nitrate, sodium bromide and lanthanum nitrate to the reaction beaker and uniformly stirring until it is dissolved, and transferring to a drying box device for hydrothermal reaction to obtain lanthanum-doped microspherical BiOBr, (ii) adding graphene oxide, chloroacetic acid and sodium hydroxide to the reaction beaker for carboxylation modification to obtain carboxylated graphene, and (iii) adding ethylene glycol solvent, lanthanum-doped microspherical BiOBr and carboxylated graphene into the reaction beaker, after ultrasonic dispersion, transferring the solution to a dry box device, and hydrothermally reacting at 140 degrees C for 2 hours to obtain lanthanum-doped microsphere BiOBr-graphene composite material. USE - The composite material is useful in field of photocatalytic degradation and sewage treatment (claimed). ADVANTAGE - The composite material: reduces recombination of carriers; has excellent modification performance; makes the conduction band potential negative shift; has large specific surface area of carboxylated graphene oxide with various oxygen-containing functional groups; plays the role of surfactant; makes the catalytic material easier to compound; solves the problem of ion agglomeration in the reaction of BiOBr; plays very good dispersion effect in aqueous solution; and is catalyst suitable for water pollution treatment worthy of development and research.