Synthesis And Field Emission Properties Of Nanostructured Metal Oxide

Nanostructured metal oxides have been widely used in the preparation of catalysts, refined ceramics,compound materials,magnetic materials,fluorescent materials, humidity-sensitive sensors and infrared-absorptive materials.With development of the nanotechnology,kinds of structures of these materials have been increasing recently. We fabricated some oxide micro/nanostructures of Tin oxide(SnO₂),Indium oxide (In₂O₃),Zinc oxide(ZnO)and Hematite(α-Fe₂O₃)in our thesis and have a research on functionalization of carbon nanotubes(CNTs).The morphology and structure was observed by SEM and HRTEM.The crystal structure is analyzed by XRD.We mainly studied the field emission properties of nanostructured metal oxides.The paper mainly contains the following works and innovations.1.We fabricated two different morphologies of self-organized hierarchical sallow-like and fishbone-like SnO₂ nanostructures made of SnO₂ nanowires by the vapor phase growth method without any metal catalyst at atmospheric pressure and discussed the growth mechanism and field emission properties of SnO₂ nanostructures in detail.We have first studied the effects of gas adsorbates on the emission properties of hierarchical SnO₂ nanostructures.2.We synthesized different morphologies of In₂O₃ micro/nanostructures using carbon thermal evaporation by changing the different technical parameters.Field emission measurements of awl-like and microcube morphologies showed that the two-section awl-like structures which has nanometer tips has better field emission properties than the cube,which makes indium oxide structures promising candidates for further applications in field emission microelectronics devices.3.Narrow back and long teeth ZnO combstructures,tetrapod-shaped,multipods and tree branch structures are deposited on Si substrate by vapor phase transport. The microscopical structures can be seen by human eyes and we observed their nanostructures by SEM.4.Hematite(α-Fe₂O₃)nanowires were synthesized by the thermal oxidation of Fe-Ni alloy grids and we had ZnO coating on surface ofα-Fe₂O₃ nanowires structures on Si substrate.We functionalized CNTs and improved their properties dissolved in solvent.