特殊形貌銀奈米結構之成長

Abstract

本篇論文中，發現新型態的銀奈米結構，這些產物是於室溫下透過簡單的銅銀置換反應，經由氧化銅網(穿透式電子顯微鏡專用)上的銅原子以還原溶液中的硝酸銀而合成出來。我們發現晶面成長控制劑對於產物的形態有著顯著的影響，如果沒有添加任何的晶面成長控制劑，在銅網表面上產生樹狀奈米結構的銀；當以四氫砆喃做為反應中的晶面成長控制劑時，可以得到一種新形態的奈米銀結構成長於銅網的碳膜上，其外觀神似於地衣，由高解析穿透式電子顯微鏡發現其片狀平面的法線方向為銀面心立方結構的[111]晶軸；最後再將晶面成長控制劑換為十六烷基三甲基氯化銨，產物展現新穎的奈米帶狀結構，其典型的寬度為20-100奈米而長度則可達5微米，這是第一次觀察到此帶狀的銀奈米一維材料，並且是以非常稀有的六方最密堆積結晶產生。

In this thesis, new morphologies of silver nanostructure were discovered. Those were synthesized through a simple Cu/Ag+ chemical displacement reaction, reducing AgNO3(aq) by Cu atoms of Cu TEM grid at room temperature. We found that the growth control agent play an important role to affect the morphology of the products. If there were no growth control agent, silver nanodendrites were produced on the surface of a copper grid. When tetrahydrofuran (THF) was used as the growth control agent in the reaction, a new lichen-like nanostructure was grown on the carbon film of the copper grid. From a high resolution transmission electron microscopic (HRTEM) image, a normal direction of the plane of the sheet was along the [111] axis of a fcc phase. Further changing the growth control agent into cetyltrimethylammonium chloride (CTAC), morphology of the products showed a novel silver nanobelt structure with typical width 20-100 nm, and a length up to 5 μm. The silver belts were synthesized for the first time in an one dimensional nanostructure which crystallized in a rare hexagonal phase.