Preparation Of Fe-based MOFs Functional Materials And Application In Removal Of Organic Pollutants In Water

Metal-organic framework compounds(MOFs)have the characteristics of large specific surface area,open channels and adjustable voids,etc.At present,as catalysts for advanced oxidation and membrane components in membrane separation technology,they have been used in the removal of organic pollutants in water,and have received extensive attention.However,the current catalytic efficiency of MOFs is still low,and how to further improve the catalytic efficiency of MOFs is still the core issue.However,the MOFs mixed membrane used for wastewater purification treatment also has the problems of low flux and low efficiency due to membrane pollution.In this paper,Fe-MOFs and BiOCl were used to construct composite materials with compact heterojunction.It can enhance the Photo-Fenton catalytic performance.The Cu(?)doped FeCu(?)BDC bimetallic MOFs catalyst was prepared by dissimilar metal ion doping,and the enhanced unsaturated ligand site and site activity.There were constructed to enhance the Fenton catalytic performance.Using bimetalline FeCu BDC with high catalytic activity as dopants,and utilizing the strong conductivity and rigidity of GOH and the ability of GO electronic bridge to promote redox reaction.A porous layered cross-flow membrane and catalytic self-cleaning system were constructed to enhance flux and selectivity,achieve rapid self-cleaning of separation membrane and extend its service life.The main conclusions are as follows:(1)BiOCl/MIL-100(Fe)composite photocatalyst was prepared and characterized by one-step coprecipitation method at room temperature for the first time.It was found that MFB-40(40%BiOCl)had the best Photo-Fenton catalytic activity.When the concentration of Rh B is 40 mg/L,the catalyst is 80 mg/L,and H₂O₂ is 7.4 mmol/L,the photodegradation rate of Fenton is 7 times and 14 times of Fenton catalytic rate,respectively.The formation of heterojunction reduces the compound efficiency of e-and h+,and increases the chance of redox reaction between Rh B and active species.More open metal sites were constructed to enhance Lewis acidity,and the generation of Fe²⁺/Fe³⁺mixed valent iron unsaturated sites also improved the catalytic efficiency.(2)FeCu(?)BDC bimetallic MOFs catalysts were prepared by hydrothermal method with Cu(?)doping and characterized.The catalytic performance of bimetallic MOFs was studied by Fenton-like catalytic degradation of Rh B by K₂S₂O₈.It was found that when the temperature was 25°C,Rh B was 100 mg/L,natural p H value,K₂S₂O₈ was 24 mmol/L,FeCu(?)BDC-1.5%was 80mg/L,Spongy octahedral FeCu(?)BDC-1.5%(99.47%),the degradation efficiency is significantly higher than Fe BDC(79.89%)and FeCu(??)BDC-25%(83.98%).The synergistic effect between the polyvalent bimetals speeds up the electron transfer efficiency.Cu(?)/Cu(??)is involved in lattice formation,resulting in ligand deletion.The coordination unsaturated sites of various metal ions improve the efficiency of PS activation to produce·S2O8^-.(3)GO/GOH/FeCu BDC ternary composite membranes with horizontal and vertical sieving structures were prepared by simple vacuum filtration method.The separation performance of dyes and the self-cleaning performance of the membranes were investigated.When rigid GOH is introduced into GO/MOFs composite membrane,the pure water flux of the membrane gradually increases.GO_0.8/GOH_0.2/FeCu BDC₄showed high throughput and high retention for the purification of dye solution,and the fluxes for MO,MB and Rh B were34.34 Lm^-2h^-1bar^-1,35.01 Lm^-2h^-1bar^-1,35.58 Lm^-2h^-1bar^-1,respectively.The interception rate was 99.46%,99.98%and 99.87%.The initial concentration,volume and p H value of dye have little effect on membrane separation performance.The multinanometer channel structure of layered ternary composite membrane effectively increases the flux and interception effect of the membrane.The addition of high conductivity GOH accelerated the electron transfer efficiency in the catalytic oxidation process and realized the rapid recovery of the membrane self-cleaning performance.