Preparation And Application Characteristics Of Montmorillonite/Copper-iron Bimetal Oxide Composite Catalyst

Montmorillonite（MT）is a clay mineral with a wide range of distribution,abundant reserves and economical benefits in my country.It has good suspension,dispersibility,adsorption,stability and non-toxicity,and has a wide range of applications.Copper-iron bimetal oxides can activate hydrogen peroxide/peroxymonosulfate（H₂O₂/PMS）to produce hydroxyl radicals/sulfate radicals(·OH/SO₄^·-)that have the characteristics of degrading pollutants.However,copper-iron bimetallic oxides,like most nanomaterials,have the problems of easy agglomeration,poor suspension in water,and low catalyst utilization.In order to solve the above problems and further improve the catalytic efficiency,this study uses natural montmorillonite as a carrier to prepare a copper-iron bimetallic oxide composite heterogeneous Fenton catalyst.The morphology and surface groups of the composite catalyst were systematically analyzed by XRD,FT-IR,and SEM characterization,and the degradation mechanism was finally explained.The main results are as follows:（1）The effective load of nano Cu₂O/Fe₂O₃ particles on the surface of MT was realized by hydrothermal method,and the performance and mechanism of montmorillonite@Cu₂O/Fe₂O₃（MT@Cu₂O/Fe₂O₃）composite material to catalyze the degradation of methylene blue（MB）by hydrogen peroxide were systematically studied.The results show that under the conditions of methylene blue concentration of100 mg/L,catalyst concentration of 0.2 g/L,and hydrogen peroxide concentration of0.4 mol/L,the degradation rate of 35%MT@Cu₂O/Fe₂O₃ to MB is 67.16%,which is The degradation rate of Cu₂O/Fe₂O₃ is 3.17 times.Moreover,cyclic experiments and ion dissolution experiments have proved that the composite catalyst has good stability.In addition,studies have confirmed that·OH plays a major role in MB degradation experiments.（2）The composite catalyst MT@Cu Fe O₂ with good suspension properties was prepared by a convenient ultrasonic dispersion method,and the performance and mechanism of the montmorillonite@Cu Fe O₂（MT@Cu Fe O₂）composite catalyzing the degradation of Congo red（CR）by PMS were systematically studied.The results show that when the Congo Red concentration is 50 mg/L,the catalyst concentration is0.2 g/L,and the PMS concentration is 20 mmol/L.When the MT content in the composite catalyst is 10%,the removal rate of Congo red per unit mass of Cu Fe O₂ is the highest.According to relevant characterization and experimental analysis,SO₄^·-plays a major role in the process of removing CR from the catalyst,followed by·OH,and the redox of Cu⁺/Cu²⁺and Fe²⁺/Fe³⁺plays a key role in the production of SO₄^·-and·OH required for degradation.（3）The effective load of Cu Fe₂O₄ nanoparticles on the surface of MT was realized by the sol-gel method,and the performance of photo-assisted-heterogeneous Fenton degrading methylene blue of montmorillonite@Cu Fe₂O₄（MT@Cu Fe₂O₄）composite was systematically studied.The results show that the concentration of methylene blue is 200 mg/L,the concentration of catalyst is 0.2 g/L,H₂O₂ is 30 mmol/L,and it is supplemented by 300 W xenon lamp.When the content of MT in the composite catalyst is 60%,the removal rate of MB is 89.11%,which is 1.63 times the removal rate of Cu Fe₂O₄,and it has good stability.In addition,the free radical quenching experiment and XPS analysis before and after the use of the catalyst show that h⁺and·OH play an important role in the degradation of MB.