Magnetic Properties And M（o|¨）ssbauer Spectroscopy Investigations Of Nano Fe₃O₄/Carbon Nanotube Composite

Carbon Nanotubes, as a kind of typical one-dimensional nano material, have a goodapplication prospect in many areas due to their unique structure, excellent electrical, magneticaland mechanical properties. Because of their fascinating nanoscale dimensions and high surfaceareas, carbon nanotubes are considered as ideal templates to directly modify nanoparticles, makingthem widely useful in more areas. It is also one of the research hotspots in recent years.In this paper Fe₃O₄magnetic nanoparticles was prepared by co-precipitation method, thenusing the co-precipitation method and thermal decomposition, the surface of carbon nanotubeswas modified with Fe₃O₄magnetic nanoparticles. The micro morphology and crystal structure ofthe matericals were characterized by SEM, TEM and XRD. Through the thermal decompositemethod, the Fe₃O₄magnetic nanoparticles were uniformly decorated on the surface of carbonnanotubes and did not exist reunion phenomenon. VSM magnetic analysis results showed that themagnetization intensity of all prepared materials would eventually reach a saturation, when theexternal magnetic field increased to a certain extent. The saturation magnetization would decreasewith the increasing of temperature. We also used a m ssbauer spectrum to analysis thecoordination environment, spin state, hyperfine field and magnetic coupling interaction of theprepared materials. The results showed that Fe₃O₄nanoparticles could be well coordinate bondedto other materials and formed a compositematerials. Due to the limitation of the pipe diameter ofthe carbon nanotubes, and preferred orientation of the growth, the pipe diameter of the Fe₃O₄nanoparticles grown on the surface of carbon nanotubes was smaller than single preparated Fe₃O₄nanoparticles. The size of the Fe₃O₄nanoparticles on the surface of the carbon nanotubes preparedby thermal decomposite method was smaller than the Fe₃O₄nanoparticles prepared bycoprecipitation method. When carbon naotubes were acidificated, ion exchange existed betweenFe2+and Fe3+. For single walled carbon naotubes, because of the role of carbon naotubes, themagnetic coupling effect enhanced among the Fe₃O₄nanoparticles.We used the Fe₃O₄/carbon tanotubes composite materials as a adsorbant for removing thecopper ion from wastewater, the results showed that the material had a good adsorption ability,and could be efficiently and rapidly separated from water in an externally magnetic field. Thisnano composite material might have a very promising application potential in the treatment ofradioactive wastewater.