Study On Construction Of α-Fe₂O₃@Fe-MOFs Fenton Catalyst And Photoelectric Synergistic Degradation Of Antibiotics

To avoid the problems of the traditional Fenton method,some researchers combine it with photocatalysis and electrochemical reactions to form a photoelectric Fenton collaborative system.The visible light can significantly improve the efficiency of generating hydroxyl radical（?OH）from hydrogen peroxide and accelerate the conversion efficiency of Fe²⁺and Fe³⁺.Introducing electrochemistry can provide a steady flow of Fe²⁺and H₂O₂ for the Fenton oxidation reaction.Their synergistic action can avoid the problem of long-distance transportation of H₂O₂.In addition,the anodic oxidation,electric absorption and other factors can accelerate the degradation of organic matter.The method has the advantages of fast reaction speed,low toxicity and good environmental compatibility at the same time,due to the abundance of iron-based catalysts,ecological friendliness,excellent magnetic selectivity,and cost-effectiveness,their application in the Fenton process has been dramatically increased.Among iron-based catalysts,hexagonalα-Fe₂O₃nanomaterials and iron-based MOFs show excellent application prospects.The heterojunction formed by combining MOFs and semiconductor photocatalysts can promote carrier migration.In addition,the synergistic effect of the Fenton reaction reduces the conductive barrier of photogenerated electron-hole pairs and dramatically improves the catalytic degradation activity.This is also because the skeleton structure of iron-based MOFs can make the catalyst disperse more evenly,thus enriching the active sites and enhancing the interaction between the catalyst and reactants.In this study,a hybrid system catalyzed by photoelectric Fenton was constructed,withα-Fe₂O₃ nanorods as the"core"and NH₂-MIL-101 and MIL-141 shells as the composite system.The photo-Fenton catalytic degradation effect of the composites was discussed through the microstructure of the composites,and the catalytic coordination mechanism was further studied.The main contents are as follows:（1）A core-shell nanorod composite array ofα-Fe₂O₃@NH₂-MIL-101 was designed.Firstly,a rod-likeα-Fe₂O₃ nanoarray was grown on the conductive surface of FTO conductive glass by hydrothermal method,which was used as the core.Then,α-Fe₂O₃ was etched with acetic acid to bind iron ions to the organic ligand diamino-telephonic acid（NH₂-BDC）in solution to obtainα-Fe₂O₃@NH₂-MIL-101 core-shell nanorod composite array.The concentration of iron ions in the solution was controlled by adjusting the amount of acetic acid to control the shell thickness.After that,XRD,SEM,TEM,and other tests were carried out to analyze the phase and microstructure of the composite materials.The photofenton and degradation properties were analyzed by XPS,UV-vis,and electrochemical tests,and then the reaction mechanism was proposed.（2）A core-shell nanorod composite array ofα-Fe₂O₃@MIL-141 was designed.Tetracarboxyphenyl porphyrin（TCPP）was prepared by hydrothermal method.Then,the rod-likeα-Fe₂O₃ nanoarray was grown on the conductive surface of the FTO conductive glass by hydrothermal method,which was used as the core.α-Fe₂O₃ was etched with acetic acid to allow iron ions to bind to the organic ligand TCPP in solution to obtainα-Fe₂O₃@MIL-141 core-shell nanorod composite array.Then the phase and morphology of the composite were analyzed by XRD,SEM,TEM,etc.The photofenton and degradation properties were analyzed by XPS,UV-vis,and electrochemical tests,and the reaction mechanism was obtained.