| Summary: | 碩士 === 國立中正大學 === 化學研究所 === 89 === Recently, nanomaterials have received considerable attention by researchers. One-dimensional nanostructured materials have attracted considerable interest of recent scientific research among nanomaterials. Over the last several years, several papers regarding the fabrication of nanowires have been reported. We demonstrate herein an electrochemical method used to fabricate suspended Au nanowhiskers with major axis of up to 150 ~ 400 nm and minor axis of ca. 3 ~ 5 nm.
The electrochemical method is employed for preparing suspended Au nanowhiskers stabilized by a mixed cationic co-surfactant system in aqueous solution. In this thesis, we report the possible growth mechanism of thus prepared Au nanowhiskers. Precursors, including small Au dots and possibly Au clusters, are formed electrochemically after the electrolysis. The growth of Au nanowhiskers are mainly completed during aging of the precursor solutions. Within the growing time, both UV-Vis. absorption spectra and TEM micrographs were measured and the observation of growth sequence were indicated and analyzed. The growth of the Au nanowhiskers turns out to follow a one-dimensional mechanism.
The absorption spectral measurements on these Au nanowhiskers have also been conducted and discussed in this thesis. A full spectrum covering UV-VIS-NIR-IR wavelength range has been measured. An indication of the dependence of the surface plasmon resonance on the particle mean aspect ratios can be described by classical electrostatic model. Calculations based on it were performed and compared to our experimental data. The implication of the result shows that the shift of the surface plasmon resonance persists for the aspect ratios ranging from 30 to 60.
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