Design Of Bismuth-Based Multicomponent Oxides And Study On Photocatalytic Degradation Of Typical Antibiotics

In recent years,in the face of the increasingly unbalanced supply and demand of traditional energy and the increasingly warming global climate,countries around the world have increased their efforts to develop and utilize new energy and energy technologies.Solar energy has great potential and can be used sustainably.It is an important energy for the harmonious development of man and nature.Semiconductor photocatalysis technology has important application prospects in the field of environment and new energy because it is driven directly by solar energy.In order to make the photocatalyst make full use of sunlight and purify water efficiently,new modified photocatalyst based on bismuth-based multi-oxide with layered structure was prepared.The photocatalytic degradation ability of the photocatalyst against typical antibiotic-contaminated wastewater under the excitation of light was discussed,and the mechanism of photocatalytic reaction was analyzed.The main contents of this thesis are as follows:（1）A novel p-n heterojunction photocatalyst（BiOCl/NaNbO₃）was constructed by simple in situ growth method.The results show that BiOCl and NaNbO₃ are closely bound in the composite sample.Compared with pure BiOCl and NaNbO₃,the composite has better photocatalytic activity for the degradation of ofloxacin（OFX）under ultraviolet light.The p-n junction formed in BiOCl/NaNbO₃ composites promotes the transfer and separation of photogenerated electron hole pairs,thus improving the photocatalytic activity.（2）A novel photostable Bi₄O₅I₂/NaNbO₃ composite photocatalyst was prepared by a simple and controllable hydrothermal method.The results showed that Bi₄O₅I₂/NaNbO₃ formed heterostructure.The degradation analysis of ofloxacin（OFX）showed that Bi₄O₅I₂/NaNbO₃composite had higher photocatalytic activity under visible light than pure Bi₄O₅I₂ and NaNbO₃samples.When the mass ratio of Bi₄O₅I₂/NaNbO₃ is 125%,the heterojunction of the composites can maximize the transfer and separation of photogenerated electron-hole pairs,thereby improving the photocatalytic activity of the materials.（3）Cu-CaBi₂O₄ composites were synthesized by simple hydrothermal method.The experimental results show that under visible light conditions,compared with pure CaBi₂O₄,the photocatalyst of Cu-CaBi₂O₄ has higher degradation activity for tetracycline hydrochloride（TC）.The Cu-CaBi₂O₄ doped materials provide an effective way for the separation of photogenerated electron hole pairs in the photocatalytic process,which improves the separation efficiency of photogenerated electron hole pairs in the doped materials and improves the photocatalytic activity of the composites.