Noble-Metal Nanotubes Prepared via a Galvanic Replacement Reaction Between Cu Nanowires and Aqueous HAuCl4, H2PtCl6, or Na2PdCl4
Noble-Metal Nanotubes Prepared via a Galvanic Replacement Reaction Between Cu Nanowires and Aqueous HAuCl4, H2PtCl6, or Na2PdCl4
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DOI：
10.1166/sam.2010.1105
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发表时间：
2010-09-01
影响因子：
0.9
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
Lu, Xiaofeng;McKiernan, Maureen;Xia, Younan
银纳米结构与HAuCl4水溶液之间的电取代反应已被广泛研究，目的是制备具有中空内部的贵金属纳米结构。本文研究了Cu纳米线与HAuCl4、H2PtCl6或Na2PdCl4之间的电替换反应，该反应也生成了空心金属纳米结构。由于Cu纳米线的Cu2+/Cu的还原电位远低于Ag+/Ag的还原电位，与Ag纳米线在沸水中进行的电替换反应相比，Cu纳米线的反应相对温和，可以在室温下进行。此外，铜纳米线的制备成本低廉，使得这种方法更适合大规模生产。在这项研究中，我们使用电子显微镜来表征Au， Pt和Pd纳米管的形态演变和最终结构。我们发现，最终的结构保留了铜纳米线的初始圆形形态，并且纳米管的表面装饰有20 nm （Au）或2 nm （Pt和Pd）的孔。利用能量色散x射线光谱（EDX），我们发现当化学计量量的HAuCl4与Cu纳米线反应时，我们可以获得纯Au纳米管。我们还评估了铂纳米管对甲酸氧化的电催化活性。
The galvanic replacement reaction between Ag nanostructures and aqueous HAuCl4 solution has been widely studied for the purpose of generating noble-metal nanostructures with hollow interiors. Here we explore the galvanic replacement reaction between Cu nanowires and HAuCl4, H2PtCl6, or Na2PdCl4, which also generates hollow metal nanostructures. Compared to the galvanic replacement reaction using Ag nanowires in boiling water, the reaction involving Cu nanowires is relatively mild and can be conducted at room temperature since the reduction potential of Cu2+/Cu is much lower than that of Ag+/Ag. Moreover, the Cu nanowires are inexpensive to prepare, making this approach more practical for large-scale production. In this study, we use electron microscopy to characterize the morphological evolution and final structure of the Au, Pt, and Pd nanotubes. We find that the final structure retains the initial circular morphology of the Cu nanowires and that the surface of the nanotubes is decorated with 20-nm (for Au) or 2-nm pores (for Pt and Pd). Using energy dispersive X-ray spectroscopy (EDX), we find that we can obtain pure Au nanotubes when a stoichiometric amount of HAuCl4 is reacted with the Cu nanowires. We also evaluate the electrocatalytic activity of the Pt nanotubes for formic acid oxidation.