Degradation Of Tetracycline Hydrochloride By Double-Z Photocatalyst Based On Iron Tungstate

In recent decades,the excessive discharge of sewage has led to the overburden of the ecological environment.The pollutants contained in the water body have seriously threatened the health of human beings and organisms.The water body itself realizes the purification of the water body through diffusion and dilution of pollutants and biochemical decomposition in the water.However,the excessive discharge of pollutants makes it difficult for the water environment to complete its own purification.In order to alleviate this severe situation,The application of photocatalytic technology to the degradation of water pollutants will be of great help to the purification of water environment.Based on FeWO₄,this paper improves its catalytic performance under visible light by constructing double Z-type heterojunction.The main research work is as follows:(1)FeWO₄/CoWO₄-g-C₃N₄ternary composite samples were prepared by simple hydrothermal method.In this paper,the surface morphology,crystal structure,chemical state and optical properties of the prepared materials were characterized.XRD and XPS studies confirmed that there were no impurities in the synthesized photocatalyst materials,and FeWO₄/CoWO₄nanoparticles had been successfully grown on g-C₃N₄nano flakes.The effect of catalyst loading on the photocatalytic degradation of tetracycline hydrochloride was investigated under visible light.FeWO₄/CoWO₄-2-g-C₃N₄composite samples degraded85.6%tetracycline hydrochloride within 80 minutes.(2)In this study,the dual Z scheme ternary photocatalyst FeWO₄/Bi₅O₇I/g-C₃N₄heterojunction with excellent photocatalytic activity was successfully prepared by one pot hydrothermal method and calcination method.Its microstructure,physicochemical and optical properties were studied through a series of tests.The photocatalytic activity of FeWO₄/Bi₅O₇I/g-C₃N₄heterojunction was significantly improved compared with pure sample and binary composite sample,and the removal rate of tetracycline hydrochloride was 87.3%in 40 minutes.(3)The preparation of dual Z scheme ternary photocatalyst CdS/FeWO₄/g-C₃N₄was made by successively anchoring FeWO₄and CdS on the surface of g-C₃N₄by two-step hydrothermal method.The surface morphology,crystal structure and chemical state of the prepared material were studied by TEM,XRD and XPS.The results confirmed that there were no impurities in the synthesized photocatalyst material,and FeWO₄and CdS nanoparticles were successfully grown on the g-C₃N₄nano sheet.The prepared sample achieved efficient removal of tetracycline hydrochloride under visible light,and the degradation rate reached83.9%in 40 minutes.In addition,the effect of catalyst on the degradation of ofloxacin was investigated under visible light.CdS/FeWO₄/g-C₃N₄-2 degraded 84.3%of ofloxacin within 40minutes.It was found that CdS/FeWO₄/g-C₃N₄-2 and FeWO₄/Bi₅O₇I/g-C₃N₄-2 had the same degradation ability of tetracycline hydrochloride under visible light,but CdS/FeWO₄/g-C₃N₄-2 had better degradation activity of ofloxacin than FeWO₄/Bi₅O₇I/g-C₃N₄-2 and FeWO₄/CoWO₄-2-g-C₃N₄,and CdS/FeWO₄/g-C₃N₄showed better photocatalytic performance.