Performance And Mechanism Of Selective Photodegradation Of Tetracycline Residues By Inorganic Imprinted Photocatalysts

In recent years,the use of tetracycline is very frequent,although it is helpful for clinical research,animal husbandry and other aspects,but with its excessive use and abuse,tetracycline residues in water has become increasingly severe,bringing serious adverse effects on the ecological environment and human health.Compared with other treatment methods of organic pollution,photocatalytic technology has the advantages of being more environmentally friendly,easy to control and highly efficient.Therefore,this study adopted photocatalytic technology to effectively treat tetracycline residual pollutants in water.The tetracycline residues in water is a kind of trace pollutant that is difficult to degrade.Therefore,in order to improve its degradation rate,this research subject introduced inorganic imprinting technology on the basis of photocatalysis technology to realize efficient and selective removal of tetracycline residual pollutants.In summary,this research topic is based on the treatment of residual tetracycline pollutants in water,using photocatalytic technology modified by inorganic imprinting to achieve selective photodegradation of residual tetracycline pollutants.Through systematic and in-depth research on different materials and systems,the universality of technology and methods is explored,aiming at laying theoretical and practical foundation for efficient treatment of low-content and difficult-to-degrade pollutants in water.The main research contents are as follows:?1?Taking advantage of tetracycline as template molecule,the rod-shaped inorganic imprinted Cd_2.56O_1.56S photocatalyst was successfully prepared by combining inorganic imprinting technology with photocatalytic technology,and using sol-gel technology and ion exchange method.XRD,XPS,TEM,SEM,UV-vis DRS and PL characterization were used to study the structure,composition,morphology and optical response of inorganic imprinted Cd_2.56O_1.56S.The degradation activity and selectivity of inorganic imprinted Cd_2.56O_1.56S were investigated by photocatalytic degradation experiment and selective experiment,and the selective photocatalytic degradation mechanism of the inorganic imprinted Cd_2.56O_1.56S was expounded.The results showed that the degradation rate of inorganic imprinted Cd_2.56O_1.56S to tetracycline in visible light was 74.38%,which was significantly higher than that of Cd_2.56O_1.56S?47.56%?.In addition,compared with Cd_2.56O_1.56S,the selectivity coefficient of inorganic imprinted Cd_2.56O_1.56S was 1.45,showing a good performance of selective photocatalytic degradation.?2?Using tetracycline as template molecule,the rod-shaped inorganic imprinted CdO photocatalyst was successfully prepared by simple one-step synthesis and calcination.XRD,XPS,TEM,SEM,UV-vis DRS,EIS and PL characterization were used to study the structure,composition,morphology and optical response of the inorganic imprinted CdO.The degradation activity and selectivity of inorganic imprinted CdO were investigated by photocatalytic degradation experiment and selective experiment,and the selective photocatalytic degradation mechanism was expounded.The results showed that the degradation rate of tetracycline by inorganic imprinted CdO was 93.22%,and the selectivity coefficient of inorganic imprinted CdO was 1.74 compared with that of CdO,showing its excellent selective photocatalytic degradation ability.?3?A magnetic inorganic imprinted BiOBr/CQDs/Fe₃O₄ heterojunction photocatalyst was successfully prepared by hydrothermal reaction and visible light elution with tetracycline as template molecule.By means of XRD,TEM,SEM,HRTEM,UV-vis DRS,EIS and PL characterization,the structure,composition,morphology and optical response of the inorganic imprinted BiOBr/CQDs/Fe₃O₄heterojunction were investigated.The VSM characterization proved that the inorganic imprinted BiOBr/CQDs/Fe₃O₄ heterojunction could be recovered and reused by magnetic separation.The degradation activity and selectivity of inorganic imprinted BiOBr/CQDs/Fe₃O₄ heterojunction were investigated by photocatalytic degradation experiment and selective experiment,and its selective photocatalytic degradation mechanism was systematically described.The results showed that the degradation rate of inorganic imprinted BiOBr/CQDs/Fe₃O₄ heterojunction to tetracycline in visible light was 81.84%,and compared with the BiOBr/CQDs/Fe₃O₄ heterojunction,the selectivity coefficient of inorganic imprinted BiOBr/CQDs/Fe₃O₄ heterojunction was2.02,showing excellent selective photocatalytic degradation activity.