▎ 摘　　要

NOVELTY - Preparing heterojunction composite photocatalyst comprises adding graphene oxide (GO) into ethylene glycol solution, ultrasonically dispersing, mixing, then adding hydrazine nitrate pentahydrate, ultrasonically dispersing, then adding ammonium metavanadate and urea, adding dilute ammonia solution to adjust pH of suspension to 7.5, placing suspension in reactor, then placing in oven at 180 degrees C, performing solvothermal reaction for 24 hours, washing resulting precipitate and drying to obtain heterojunction composite photocatalyst. USE - The photocatalyst is useful for catalytic degradation of antibiotics under visible light (claimed). DETAILED DESCRIPTION - Preparing heterojunction composite photocatalyst i.e. bismuth-vanadium/reduced graphene oxide (Bi4V2O11/RGO) comprises adding graphene oxide (GO) into ethylene glycol solution, ultrasonically dispersing, mixing, then adding hydrazine nitrate pentahydrate, ultrasonically dispersing, then adding ammonium metavanadate and urea, adding dilute ammonia solution to adjust pH of suspension to 7.5, placing suspension in reactor, then placing in oven at 180 degrees C, performing solvothermal reaction for 24 hours, washing resulting precipitate and drying to obtain heterojunction composite photocatalyst.