利用賈凡尼置換法合成奈米銅線與銅帶

Abstract

本論文的研究乃在於利用簡易的賈凡尼置換反應(galvanic displacement reaction)，於溶液中添加十六烷基三甲基氯化銨(cetyltrimethylammonium chloride; CTAC)與HNO3以合成樹狀、線狀與緞帶狀奈米銅。實驗結果發現， CTAC的添加對於產物形態有著顯著的影響：如果溶液中沒有添加任何CTAC時，鋁金屬與CuCl2水溶液中的Cu2+離子會進行自發性的氧化還原反應得到樹狀結構的奈米銅；當添加適量CTAC做為晶面成長控制劑時，產物形態轉變為[100]方向成長的線狀結構，線寬約30-50 nm，長度可達1 µm；若是再添加適量HNO3於反應溶液中，便可得到新穎的奈米緞帶結構，其寬度大約分布在30-100 nm間，厚度小於10 nm，長度可達數十µm，微結構鑑定顯示此帶狀結構傾向延著[100]方向成長。由於銅為良導體且平整的奈米長薄片結構擁有高表面積的特性，預期此奈米銅帶將深具應用的潛力。

In this study, novel nanostructures of metal copper are discovered, including dendritic shape, wire shape and ribbon shape. Those were fabricated using galvanic displacement reaction on aluminum grid. We found that cetyltrimethylammonium chloride (CTAC) played an important role to affect the morphology of the products. If CTAC is absent in the reaction solution, copper nanodendrites were produced in the spontaneous Al-Cu2+ redox process. When CTAC was used as the growth control agent in the reaction, crystalline Cu nanowires with diameter of 30-50 nm and length up to 1 μm were grown on the substrate surfaces. Each nanowire exhibited crystallinity with [100] orientation. Further adding HNO3 into the reaction solution, large amount of ribbon-like nanobelts were made. Each nanobelt has a uniform width along its entire length, and typical widths of the nanobelts are in the range of 30-100 nm. The TEM image and diffraction patterns indicate that nanosheet structure of Cu was formed by fast growth along [100], whereas growth along [001] is suppressed, resulting in the formation of a thin sheet type of structure. Because Cu is a conductance and nanobelt structures have the high surface area, we hope their potential use as interconnects in the future nanoelectronics and application for nanosensors.