Preparation Of Functional Fe₃O₄/C And Its Adsorption Properties

Functionalized carbon coated Fe3O4(Fe3O4/C)particles with superparamagnetism were prepared by combining Fe3O4 particles with superparamagnetism and biomass carbon activated with abundant functional groups in this paper.Functionalized Fe3O4/C particles,because of the advantages of rich-COOH and-OH functional groups onto its surface and easy separation,were extensively used in removing contaminants from wastewater including dyes,heavy metal ion and protein.On the first step,Fe3O4/C particles,taking respectively Fe3O4 and glucose as supporter and carbon source,were prepared successfully by hydrothermal synthesis in this paper.Then,Fe3O4/C particles functionalized with chloroacetic acid(Fe3O4/C-CAA),core-shell magnetic manganese dioxide(Fe3O4/C/MnO2)and citric acid modified magnetic manganese dioxide(Fe3O4/C/MnO2-CA)three particles were prepared by surface modification of Fe3O4/C particles.Fe3O4/C,Fe3O4/C-CAA,Fe3O4/C/MnO2 and Fe3O4/C/MnO2-CA were respectively characterized by transmission electron microscopy(TEM),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),X-ray powder diffraction(XRD),Brunauer-Emmett-Teller(BET),vibration sample magnetometer(VSM)and energy-dispersive X-ray spectroscopy(EDS).The results showed four particles all were defined well core-shell structure and with superparamagnetism.The results of TEM and SEM analysis showed the diameters of Fe3O4,Fe3O4/C,Fe3O4/C-CAA,Fe3O4/C/MnO2 and Fe3O4/C/MnO2-CA particles were about 300 nm,320 nm,320 nm,380 nm and 380 nm.And,the thickness of the shell of Fe3O4/C,Fe3O4/C-CAA,Fe3O4/C/MnO2 and Fe3O4/C/MnO2-CA particles were around 10 nm,10 nm,40 nm and 40 nm,respectively.According to the results of XRD analysis,the crystalline phases of Fe3O4/C,Fe3O4/C-CAA,Fe3O4/C/MnO2 and Fe3O4/C/MnO2-CA four particles were in accordance with that of Fe3O4 and their outer shell were amorphous.The maximal saturation magnetizations of four particles were 65.5 emu/g,64.3 emu/g,23.8 emu/g and 21.3 emu/g,respectively.This feature made four particles separate rapidly from solution.In the experiment of adsorption test,it was found that the adsorption isotherm and kinetic model of all particles belongedto Langmuir model and pseudo-second-order model,respectively.The adsorption amount of methylene blue(MB)onto Fe3O4/C-CAA particles was about 124.28 mg/g,1.7 times of that of Fe3O4/C and time of reaching equilibrium was around 210 min.The adsorption amount of Fe3O4/C/MnO2 particles to MB was around 43.34 mg/g,the time of reaching equilibrium was shortened greatly,about 20 min.It was Fe3O4/C/MnO2-CA particles that not only possessed higher adsorption capacity(about 66.31 mg/g)than Fe3O4/C/MnO2,but also cutted the adsorption equilibrium time(about 20 min)enormously than Fe3O4/C.And,Fe3Oa/C,Fe3O4/C-CAA,Fe3O4/C/MnO2 and Fe3O4/C/MnO2-CA four particles all were with favorable cycling performance.