Study On Fabrication And Properties Of Iron Oxide Nanoparticles

With the rapid development of nanotechnology,iron oxide nanomaterials are playing important roles in real life and scientific research due to their unique physical and chemical properties.The main fields of applications include catalyses,new energy,gas sensors,electronic materials,environment depollution,biomedicine and magnetic media.In this dissertation,Fe₃O₄ magnetic nanoparticles?MNPs?and hematite??-Fe₂O₃?nanoparticles were fabricated by chemical co-precipitation method and cathodic electrochemical deposition with well decentralized features and controllable sizes.Highly ordered electrode arrays composed of hematite nanoparticles were also deposited on the laser interference patterned indium-tin-oxide?ITO?films followed by cathodic electrochemical deposition.The main contents are summarized as follows:1.Fe₃O₄ MNPs were synthesized by the chemical co-precipitation method.The X-ray diffractometer?XRD?,scanning electron microscope?SEM?and magnetic force microscope?MFM?were used to characterize the Fe₃O₄ MNPs.Polyethylene glycol 2000?PEG-2000?was chosen as the dispersant.The experiment results have shown that this method is able to obtain the decentralized Fe₃O₄ MNPs with the average diameter of 99.6nm for different potential applications.2.Cathodic electrochemical deposition was proposed to fabricate reproducible and homogeneous hematite??-Fe₂O₃?nanoparticles on indium-tin-oxide?ITO?films.Well decentralized ?-Fe₂O₃ nanoparticles,which were quasi-hexagonally shaped,were deposited in an aqueous mixture of FeCl2 and FeCl3 with a conventional three-electrode and single-compartment electrochemical cell.The work electrode was an ITO film coated glass substrate.The counter electrode was an iron plate and the reference electrode was a standard calomel reference electrode.Raman spectroscope,XRD and SEM were used to characterize the morphology and microstructure of the ?-Fe₂O₃ nanoparticles.The experiment results have shown that the size and shape of nanoparticles were determined by electrochemical deposition conditions including the deposition time,current density,reaction temperature and solution concentration.3.Highly ordered electrode arrays composed of ?-Fe₂O₃ nanoparticles were deposited on the laser interference patterned indium-tin-oxide?ITO?films followed by cathodic electrochemical deposition.Taking the advantage of laser interference lithography,the grating period and structure can be precisely controlled by changing the parameters such as the incident angle,wavelength,phase,polarization angle,energy and number of laser beams,and the shape and size of ?-Fe₂O₃ nanoparticles can be determined by the electrochemical deposition conditions.