Synthesization Of Metal Ion Doped Fe₃O₄ Nanomaterials For Fenton Antibacterial

Water pollution is one of the main challenges in this global.Pathogenic microorganisms are one of the most common pollutants in sewage.Efficient disinfection methods for pathogenic microorganisms is beneficial for the environment safety of human being.Advanced oxidation technology(APOs)is a hot research topic in the field of water treatment.Among APOs,Fenton reaction technology has unique advantages.This technology can efficiently disinfecte pathogenic microorganisms by using hydroxyl radical and other reactive oxygen groups which generated in the reaction process of oxidizer and catalyst Fe₃O₄ nanoparticles is a recyclable catalyst for pollutant treatment and have attracted extensive attention due to their stability and biocompatibility.In this study,Fe₃O₄ namomaterial was modified by solvothermal method,and a series of Mg²⁺?Zn²⁺?Ni²⁺-Fe₃O₄,Mn²⁺-Fe₃O₄ and Cu²⁺-Fe₃O₄ nanocomposites were successively prepared.X-ray diffraction(XRD),scanning electron microscopy(SEM),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),electron paramagnetic resonance spectrometer(ESR),Hysteresis loop(M-H)and inductively coupled plasma mass spectrometer(ICP-MS)were used for characterization of the structure,morphology and Fenton reactivity of the above composites.The levofloxacin(LEV)and rhodamine B(Rh B)dyes were used as the target degradation substances.In addition,Escherichia coli K12 was used as the model bacteria to study the Fenton reaction bactericidal performance.The specific research contents and results shows as below:1.Mg²⁺?Zn²⁺?Ni²⁺-Fe₃O₄ nanocomposites were synthesized by solvothermal method.Using XRD,SEM,FESEM and XPS tests,the prepared nanocomposites was successfully characterized.The Fenton reaction disinfection experiment demonstrated that those three nanocomposites have weak inactivation effect on E.coli.The results showed that the survival rate of E.coli was about 70%after three kinds of composite materials were treated for 3 hours.The degradation rate of Rh B dye was about 40%after treated with Zn²⁺-Fe₃O₄ nanocomposites for 2 hours.2.Mn²⁺doped Fe₃O₄ nanocomposites were prepared according to the above method.The structure and magnetic properties of Mn²⁺-Fe₃O₄ nanocomposites were tested by XRD,XPS,SEM,FESEM and M-H.ESR experiment showed that hydroxyl radicals were the functional group in the process of degradation and sterilization.The result of ICP-MS showed that Mn²⁺precipitation in aqueous solution meets the national drinking water safety standard.The degradation results showed that the synthesized material had efficiently effect on LEV,which could be completely degraded in 100 min.The disinfection effect of E.coli was enhanced than above three nanocomposites,and the survival rate was about 63%after Fenton treatment for2.5h.3.Cu²⁺-Fe₃O₄ nanocomposites were synthesized by above solvothermal method.By XRD,SEM,XPS and TEM tests,the Cu²⁺doped Fe₃O₄ nanomaterials was successfully prepared.The free radical and magnetic properties of the composites were measured by ESR and M-H.The results of Fenton reaction performance test showed that 10%Cu²⁺-Fe₃O₄ nanocomposites had best bactericidal ability.E.coli cell can be reduced by seven orders of magnitude after treated about 2 hours which is the highest activity in this study.Rh B dye also can be completely degraded within 100 min.