Preparation And Photocatalytic Properties Of BiYO₃-ZnO Composite

Nano ZnO has been widely used in antibacterial and degradation fields due to its excellent photocatalytic properties.However,Zn O has a large band gap width and only responds to ultraviolet light,resulting in low effective utilization of light.In order to improve the photocatalytic activity of Zn O,BiYO₃-ZnO composite photocatalytic materials from Bi YO₃ and Zn O through hydrothermal combined solid phase calcination,The photocatalytic performance of BiYO₃-ZnO composite photocatalytic materials was explored.and they were applied to the treatment of livestock and poultry wastewater.The specific content is as follows:（1）A type I heterojunction BiYO₃-ZnO composite photocatalytic material was synthesized by hydrothermal combined solid phase calcination,and the successful synthesis of BiYO₃-ZnO was confirmed by XRD,SEM,UV-vis,and other characterization methods,And the composition has not changed;The photoelectrochemical analysis showed that BiYO₃-ZnO composite photocatalytic material had better photocatalytic performance compared to two single materials.（2）The antibacterial activity of BiYO₃-ZnO composite photocatalyst material against Escherichia coli,Staphylococcus aureus,and Candida albicans under 35 W LED light irradiation was investigated.The results showed that the antibacterial properties of the prepared BiYO₃-ZnO composite photocatalytic material increased with the increase of illumination time and the concentration of the composite photocatalytic material.Among them,500 mg/L 1:3 BiYO₃-ZnO composite photocatalyst material has the best antibacterial effect against Escherichia coli and Staphylococcus aureus,and the antibacterial rate reaches 100%when irradiated for 120min and 150 min respectively;When 1000 mg/L of 1:3 BiYO₃-ZnO composite photocatalytic material was irradiated for 240 min,its antibacterial effect against Candida albicans was the best,with an antibacterial rate of 92.06%.The photocatalytic and antibacterial properties of BiYO₃-ZnO composite photocatalytic materials are superior to those of Bi YO₃ and Zn O single materials.（3）The photocatalytic degradation ability of BiYO₃-ZnO composite photocatalytic materials for tetracycline hydrochloride was investigated using a 35W LED lamp as a light source.The results showed that the photocatalytic degradation performance of tetracycline hydrochloride increased with the increase of illumination time and the concentration of composite photocatalytic materials.The photocatalytic degradation efficiency of BiYO₃-ZnO composite photocatalyst material with a concentration of 500 mg/L and a concentration of 16 mg/L of tetracycline hydrochloride was the best when irradiated for 120 minutes,with a degradation rate of 82.03%,which was superior to the photocatalytic degradation efficiency of two single materials for tetracycline hydrochloride.After five cycles of experiments,the BiYO₃-ZnO composite photocatalytic material still has a degradation efficiency of 69.39%for tetracycline hydrochloride.（4）The treatment ability of BiYO₃-ZnO composite photocatalytic materials for livestock and poultry breeding wastewater was investigated.With a 35W LED lamp as the light source and a concentration of 500 mg/L of BiYO₃-ZnO composite photocatalytic material,BiYO₃-ZnO composite photocatalytic material has good removal/reduction effects on bacterial colonies,total phosphorus（TP）,total nitrogen（TN）,and chemical oxygen demand（COD）in livestock and poultry wastewater samples,with a classification of 100%,51.97%,78.83%,and 77.42%.Through cytotoxicity experiments,it has been proved that when the concentration of BiYO₃-ZnO composite photocatalytic material is not higher than 1 g/L,there is no cytotoxicity.The plant toxicity test showed that the livestock and poultry wastewater treated with BiYO₃-ZnO composite photocatalytic material had no plant toxicity.It has a good application prospect in treating livestock and poultry wastewater.