The Paperation Of A Novel Magnetic EDTA Functionalized CoFe₂O₄ Nanoparticles And Their Study Of Adsorption And Catalytic Ability

Recently,water pollution has become a threat to human lives.How to remove contaminants in water efficiently becomes a hot topic at home and abroad.Ferrites have aroused attention in the field of water treatment due to their large specific surface area,sensitive magnetic responsiveness and ease of functionalizat ion.Among all ferrites,spinel cobalt ferrite nanomaterials attract attention because of their excellent properties.However,the easy agglomeration in aqueous solution decreased their performance.In this study,EDTA-functionalized CoFe₂O₄ nanoparticles were prepared and aim to optimize adsorption and catalytic performance of pure CoFe₂O₄.The main contents are as follows:?1?EDTA-functionalized CoFe₂O₄ nanoparticles were prepared by a simple hydrothermal method,and the products were denoted as EDTA-MNP-1,EDTA-MNP-2,EDTA-MNP-3 and EDTA-MNP-4 according to the dosage of EDTA.Although saturation magnetization property had reduced after the addition of EDTA,the nanoparticles still can be quickly separated from the aqueous solution under external magnetic field.Although the addition of EDTA will increases the physical properties of EDTA-MNP,such as specific surface area,pore size,pore volume and so on.But excessive dosage of EDTA trends to accumulate on the surface of CoFe₂O₄and reduce the stability of EDTA-MNP.?2?The adsorption ability of EDTA-MNP was detecting by adsorption experiment of Cu???in aqueous solution.The results show that the addition of EDTA greatly improves the adsorption ability of Cu???compares to pure CoFe₂O₄.Experiment suggested that the pseudo-second-order model and Langumuir model showed the best correlation with the adsorption data,and the estimated maximum adsorption capacity of EDTA-MNP-1 was 73.26mg·g^-1 at 323 K,displaying a higher efficiency than previously reported adsorbents.The adsorption capacity of EDTA-MNP-1 toward Cu???remained above 90%after four adsorption-desorption cycles.Experiments show that EDTA-MNP-1 is a stable,effective and potential adsorbent for removing Cu?II?from aqueous solution.?3?EDTA-MNP-1 was chosen as a novel heterogeneous catalyst to activate peroxymonosulfate?PMS?to removal OG from aqueous solution.A degradation efficiency of 93%was achieved within 15 min in EDTA-MNP-1/PMS sysrem,while only 57%of OG was degraded within 15 min in CoFe₂O₄/PMS system at the same conditions,indicating the addition of EDTA can greatly enhance OG removal efficiency.The degradation of OG followed pseudo-first-order kinetics,and higher efficiency of OG oxidation was observed within a wide pH range?3.0-9.0?.Both of theSO₄^-?and OH?were produced in the reaction according to the radical scavenging tests and electron paramagnetic resonance?EPR?analysis,butSO₄^-?seems to be the dominant active species compares to OH?.EDTA-MNP-1 after four catalytic reactions to can still reach 82%of OG removal rate within 30 min,proving that EDTA-MNP is a stable and reliable heterogeneous catalyst.In summary,the method of EDTA functionalized CoFe₂O₄ could enhance the performance of cobalt ferrite was affirmed,and proved that EDTA-MNP is a stable,effective,reusable material of water treatment,and the two experiments were a good reference for EDTA and CoFe₂O₄ in actual application.