Synthesis Of Zinc Ferrite Composite And Their Performance In Photocatalytic Degradation Of Antibiotics

With the research and development of antibiotic drugs,tetracycline antibiotics,as broad-spectrum antibiotics,are widely used in agricultural production,aquaculture,and disease treatment due to their low cost.A large amount of wastewater has been generated during their production and use which causes serious negative impacts on the environment if discharged directly without treatment.Among the many techniques used for degradation,photocatalytic degradation has good prospects in antibiotic wastewater treatment because of its low cost,non-toxicity,green,and other advantages.Zinc ferrite（ZnFe₂O₄）,a spinel-type material,is a promising photocatalytic material because of its narrow bandgap width（1.9 e V）,excellent visible light absorption,magnetic properties,and high chemical stability.However,its high electron-hole recombination rate and low quantum efficiency still leave much room for improvement of photocatalytic performance.In this work,with a focus on improving the catalytic activity of ZnFe₂O₄ based materials,we have combined the advantages of various materials to prepare efficient and stable composites by selecting the best composition of the system.Their catalytic activity has been characterized and investigated by their microstructure,morphology,and optical properties.The main contents are as follows.1.ZnFe₂O₄ with different doping amounts of rare earth elements and Ag loadings were synthesized by hydrothermal method,and on this basis,C₃N₄ and ZnO were compoited to prepare the ZnFe₂O₄-based composites.2.Crystal structure,morphological features,and optical properties of the system have been characterized and analyzed by XRD,TEM,IR and UV-Vis.3.Using tetracycline hydrochloride as the target contaminant,the effect on the degradation rate of antibiotics under different synthesis conditions was investigated in the catalyst/H₂O₂/visible light system,and the optimal ratios of C₃N₄/ZnFe_2-xM_xO₄ and ZnO/Ag@ZnFe₂O₄ were determined for the best catalytic performance.70%-ZnO/Ag@ZnFe₂O₄showed the best removal effect on antibiotics,and the degradation rate reached 91%at 80 min of light irradiation.Isopropyl alcohol strongly inhibits the degradation rate,which indicates that the hydroxyl radicals（·OH）have been trapped by isopropyl alcohol.