▎ 摘　　要

NOVELTY - Preparation of graphene modified erbium-doped cerium oxide-bismuth oxybromide heterojunction photocatalytic degradation material includes adding deionized water and graphene oxide to beaker, dropping sodium carbonate aqueous solution to adjust pH, adding sodium borohydride reducing agent, placing beaker to a water bath, heating, filtering, washing, and drying to obtain reduced graphene oxide; mixing deionized water, ethylene glycol, cerium nitrate, erbium nitrate and polyvinylpyrrolidone, ultrasonicating, adding oxalic acid, ultrasonicating, centrifuging, washing, drying, and calcining to obtain porous erbium-doped cerium oxide; and adding ethylene glycol and reduced graphene oxide to a beaker, ultrasonicating, adding cetyltrimethylammonium bromide, bismuth nitrate and urea, ultrasonically dispersing, adding potassium bromide, stirring, adding to reactor, reacting, cooling, centrifuging, washing, and drying to obtain graphene-modified petal-like bismuth oxybromide. USE - The method is for preparation of graphene modified erbium-doped cerium oxide-bismuth oxybromide heterojunction photocatalytic degradation material. ADVANTAGE - The material has large number of pore structures which increases the contact area with sunlight, large number of slit-like voids which effectively inhibit photo-generated electron-hole recombination, and excellent photocatalytic degradation performance of tetracycline. The method replaces cerium ion positions with erbium ions, and generates oxygen vacancy defects in the crystal lattice which can be used as traps for photo-generated electrons and delay the recombination of photo-generated electrons and holes. DETAILED DESCRIPTION - Preparation of graphene modified erbium-doped cerium oxide-bismuth oxybromide heterojunction photocatalytic degradation material comprises: (A) adding deionized water and graphene oxide to beaker to obtain colloidal solution, dropping sodium carbonate aqueous solution to adjust pH to 8-10, adding sodium borohydride reducing agent, placing beaker to a water bath, heating to 70-90 degrees C for 30-90 minutes, filtering, washing, and drying to obtain reduced graphene oxide; (B) mixing deionized water, ethylene glycol, cerium nitrate, erbium nitrate and polyvinylpyrrolidone, ultrasonicating for 5-10 minutes, adding oxalic acid, ultrasonicating for 2-6 hours, centrifuging, washing, drying to obtain erbium-doped cerium oxalate, and calcining to obtain porous erbium-doped cerium oxide; (C) adding ethylene glycol and reduced graphene oxide to a beaker, ultrasonicating for 1-3 hours, adding cetyltrimethylammonium bromide, bismuth nitrate and urea, ultrasonically dispersing for 30-90 minutes, adding potassium bromide, stirring, adding to reactor, reacting at 140-180 degrees C for 6-18 hours, cooling, centrifuging, washing, and drying to obtain graphene-modified petal-like bismuth oxybromide; and (D) adding deionized water, porous erbium-doped cerium oxide and graphene-modified petal-like bismuth oxybromide to a beaker, sonicating for 2-4 hours, standing for 4-8 hours, centrifuging, washing, and drying. The mass ratio of graphene oxide to sodium borohydride is 15-25:100.