Study Of The Preparation And Properties Of The Iron Element Nanoparticles

In this thesis, synthesis conditions for the fabrications of several nanostructures of iron, cobalt, nickel and iron sulfide with different shapes were studied. These nanostructures were characterized by transmission electron microscopy (TEM), select area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectroscopy (EDS), X-ray difrraction(XRD). And thermalgravitymatric analyzer (TGA), superconducting quantum interference device (SQUID) vibrating sample magnetometer and electrochemical station (CHI660) were used to test the magnetic properties of these nanostructures. The main results were as follows:1. Alpha-Fe nanocubes were synthesized by reaction of FeCl₃ with NaBH₄, and the average diameter of these nanoparticles was about 100 nm. To our knowledge, it is the first example of cubic Fe nanostructure prepared in aqueous solution. The yield was higher than 80% and the ratio of cubic particle was as high as 90%. Also, SiO₂, ZrO₂ and PS coated Fe nanostructures were obtained, which could protect Fe from oxidation, and keep the magnetic properties of Fe nanoparticles stable.2. CoNi bimetallic hollow nanospheres and taraxacum-like particles were prepared in water/PEG/hexamethylene system and CTAB solution, respectively. Results from VSM tests indicated the two different shaped nanostuctures were all soft magnetic materials with relative low coercivities. It is expected that they have potential applications as high frequency materials.3. A novel flake-shaped FeS nanoparticle was obtained in dodecylamine chloride system. The electrocatalytic performances in reducing H₂O₂ of the FeS modified glass carbon electrode (GCE) were investigated. The results revealed that H₂O₂ sensor from the FeS nanoflakes had good responses and stability for a wide range of 0.5 to 150μM and the detection limit is 5.2×10^-8M.