| Summary: | 碩士 === 國立東華大學 === 物理學系 === 103 === Mechanisms of acetone-catalyzed one-dimensional growth of TiO2:C core-shell nanowires have been investigated. A home-made apparatus was designed and constructed to realize growth experiments utilizing resistive Joule-heating. The achieved high heating and cooling rates allowed exploring the very early growth stages, providing fundamental information for the growth mechanism that had been inaccessible using the conventional chemical-vapor-deposition system. Observations using SEM, Raman scattering, and TEM revealed that the rutile TiO2 core can grow in a single-crystalline or ploy-crystalline mode with drastically different axial growth rates, being controlled by the substrate temperature and the used flow rate of the catalyzing gas. Based on experimental observations, a new model is proposed to describe the deposition processes of the carbon shell onto the TiO2 core.
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