Adsorption And Degradation Of Tetracycline By Metal-Organic Framework And Functionalized Fibers

In this study,Fe-based MOF was selected as the adsorbent and photocatalyst for tetracycline.Two different methods(hydrothermal method and room temperature method)were used to synthesize MIL-100(Fe),and the hydrothermal method was used to synthesize MIL-101(Fe).SEM and particle size testing were used to characterize the external morphology and size distribution of the Fe-based MOF;XRD,FTIR and XPS tests were used to analyze its chemical composition;BET,TG and DRS tests were used to analyze its physical properties.The adsorption isotherm model and adsorption kinetics were used to study the adsorption behavior of Fe-based MOF to tetracycline hydrochloride.Finally,the performance of Fe-based MOF on the photocatalytic degradation of tetracycline hydrochloride was studied by the controlled variable method.The results showed that the octahedral MIL-100(Fe)with smooth surface and good thermal stability was successfully synthesized by the hydrothermal method and the normal temperature method.And its specific surface area reached 1084.9 m~2/g and1421.7m~2/g,respectively.The adsorption behavior of tetracycline on MIL-100(Fe)prepared by the room temperature method conforms to the Langmuir model and the quasi-secondary adsorption kinetics.And it’s adsorption degradation efficiency of tetracycline is 41.1%,the photocatalytic degradation efficiency is 16.7%,and the total degradation efficiency is 57.8%.The octahedral MIL-101(Fe)with particle surface and good thermal stability was successfully synthesized by hydrothermal method,and its specific surface area was 204.95m~2/g.The adsorption behavior of MIL-101(Fe)for tetracycline conforms to the Freundlich model and quasi-secondary adsorption kinetics.And it’s adsorption degradation efficiency of tetracycline is 52.5%,the photocatalytic degradation efficiency is 42.8%,and the total degradation efficiency reaches 95.3%.Polyacrylonitrile(PAN)is used as the base material to carry Fe-based MOF to prepare composite nanofibers to improve the recycling performance of MOF materials.Using mixed solvents,the electrospinning method is used to prepare nanofibers with rough surfaces.Thus,the Fe-based MOF exposes more surface area to photocatalysis the tetracycline.XRD and FTIR tests were used to analyze the chemical composition of the Fe-based MOF composite nanofibers,and the physical properties were analyzed using BET and tensile stress-strain curves.Finally,the photocatalytic degradation performance and cycle stability of the prepared Fe-based MOF composite nanofibers for tetracycline were studied.The results show that when the PAN concentration is 12wt%and the mass ratio of mixed solvent chloroform(CF)and N,N-dimethylformamide(DMF)is 1:9,the nanofibers spun have the best morphology and the diameter is about 700nm.It is most suitable for mounting Fe-based MOF.The mechanical properties of the nanofiber membrane will increase with the addition of CF,and the mechanical properties will decrease with the addition of Fe-based MOF,and the specific surface area will increase.Equipped with MIL-101(Fe)nanofiber membrane degradation adsorption efficiency was 55.2%tetracycline,photocatalytic degradation efficiency was 34.5%,the total degradation efficiency of 89.7%,is significantly superior MIL-100(Fe)composite nanofiber membrane.The total degradation rate of MIL-101(Fe)nanofiber membrane is maintained at 75%after five times of photocatalysis,and the cycle performance is good.