▎ 摘　　要

NOVELTY - Method for preparing a composite photocatalyst, involves (a) dispersing graphene oxide into an ethanol solution, dissolving a tungsten source in the graphene alcohol solution, and dripping acetic acid solution to obtain a solution (A), taking a bismuth source and dissolving in deionized water, dripping the bismuth source solution into the solution (A), and ultrasonically stirring, subsequently transferring the mixed solution to a hydrothermal synthesis device for reaction, and reacting to obtain a graphene-bismuth tungstate composite, and (b) dispersing a bismuth source into an ethylene glycol solution, dispersing the graphene-bismuth tungstate composite obtained in step (a) into the solution, and ultrasonically stirring, and transferring the resulting solution to a microwave reaction synthesis device reacting and drying. USE - The method is used for preparing a composite photocatalyst with a graphene-based hollow hierarchical structure, which is used in the treatment of dye wastewater (claimed). ADVANTAGE - The method is simple, and has short preparation time, and high efficiency, safety and reliability. The synthesized composite photocatalyst has controllable morphology and high specific surface area, and can efficiently adsorb and degrade organic matter in dye wastewater and decompose it into water and carbon dioxide under visible light,. DETAILED DESCRIPTION - Method for preparing a composite photocatalyst with a graphene-based hollow hierarchical structure, involves (a) dispersing 5-100 mg graphene oxide into a 5-10 ml ethanol solution under ultrasonic conditions, dissolving 0.001-0.01 mol tungsten source in the graphene alcohol solution, and dripping acetic acid solution to obtain a solution (A), taking 0.001-0.01 mol bismuth source and dissolving in deionized water, dripping the bismuth source solution into the solution (A) under ultrasonic conditions, and ultrasonically stirring to make it uniformly mixed, subsequently transferring the mixed solution to a hydrothermal synthesis device for reaction, and after completing the reaction, performing suction filtration, washing and vacuum drying to obtain a graphene-bismuth tungstate composite, and (b) dispersing 0.001-0.01 mol bismuth source into a 50-100 vol.% ethylene glycol solution under ultrasonic conditions, dispersing the graphene-bismuth tungstate composite obtained in step (a) into the solution under ultrasonic conditions, and ultrasonically stirring to make it uniformly mixed, and transferring the resulting solution to a microwave reaction synthesis device for reaction after completing the mixing, and after completing the reaction, performing suction filtration, washing and drying to obtain a hollow graded composite photocatalyst deposited with graphene-based metal particles.