以低溫水溶液法合成氧化鋅奈米線之研究

Zinc Oxide Nanowires Synthesized by Low-temperature Aqueous Solution Method

王貞雲(Chen-Yun Wang)

指導教授 ： 王錫福 ； 曾俊元

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2007年)

https://doi.org/10.6841/NTUT.2007.00145

摘要

本實驗利用低溫水溶液法在預鍍一層氧化鋅薄膜當做緩衝層的矽基板上，於硝酸鋅（Zn(NO3)2．6H2O）及六亞甲基四胺（C6H12N4）混合水溶液中，合成氧化鋅奈米線（ZnO nanowires）。首先探討基板緩衝層結晶性及表面型態對氧化鋅奈米線晶體成長之影響；再進行反應物濃度和持溫時間等參數的改變對氧化鋅型態的影響。
實驗結果發現，基板上方氧化鋅緩衝層的結晶方向對於後續以低溫水溶液法所合成的一維氧化鋅結晶方向有明顯的影響，氧化鋅緩衝層若沿[0002]方向成長，一維氧化鋅（氧化鋅奈米線）成長方向會趨向愈一致；而緩衝層表面的粗糙程度也會影響到一維氧化鋅的成核分佈情況，粗糙度愈大成核位置越多，所成長的氧化鋅奈米線也愈密集。氧化鋅奈米線成長過程中，適當的攪拌反應水溶液，會有利於氧化鋅生長的速率；反應物比例主要影響溶液中離子反應的速度，當硝酸鋅含量大於六亞甲基四胺含量時，一維結構在長度上會擁有較佳的一致性；反應物濃度的高低會影響氧化鋅奈米線的直徑大小，濃度越高，氧化鋅奈米線直徑越大且六方晶的結晶越佳。本實驗以0.05 M的濃度所成長的氧化鋅奈米線具有結晶性最佳的六方晶；氧化鋅奈米線長度會隨著持溫時間的增加而明顯增加，直徑則是隨之呈現小幅度成長。延長持溫時間或是增加反應物濃度可以奈米線的製程方式合成氧化鋅薄膜。氧化鋅奈米線成長屬於一個可逆的反應，當反應物離子隨著反應時間的延長而耗盡時，化學反應會開始朝逆反應方向進行，氧化鋅奈米線從[0002]方向開始溶解，而形成氧化鋅管狀結構。

關鍵字

水溶液法 ； 奈米材料氧化鋅奈米線

並列摘要

In this study, zinc oxide nanowires was successfully grown on ZnO/Si substrate using low-temperature aqueous solution method. We firstly study the influences of the ZnO buffer layer on the Si substrate on the crystal direction of zinc oxide nanowires. Then the effects of solution concentration, growth time, and the ratio of Zn(NO3)2 and C6H12N4 in the solution on the morphology and size of zinc oxide nanowires were also investigated.
Our experimental results indicate that the zinc oxide nanowires have uniform C-axis preferred orientation when the zinc oxide buffer layer grows along [0001] direction. The surface roughness of zinc oxide buffer layer would affect the nucleus sites of zinc oxide nanowires, the higher the surface roughness is, the larger number of the nucleus sites is, which leads to high number density of nanowires grown. If the solution is stirred incessantly, the growth rate of the nanowires increases. The diameter of zinc oxide nanowires is determined by the concentration of solution. In our experiment, we can obtain the high quality columnar grain with hexagonal structure when the concentration of solution is 0.05 M. If the content of Zn(NO3)2 is more than C6H12N4, the length of zinc oxide nanowires is almost equal and is increased with an increase of reaction time. We also can obtain other geometries of zinc oxide such as ZnO thin film or ZnO nanotube, by suitably controlling the processing parameters of reaction time and concentration.

並列關鍵字

aqueous solution method ； ZnO nanowires ； nano-materials

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