Dendritic gold nanowires supported on SiO2 nanoparticles fabricated by a seed growth method
Dendritic gold nanowires supported on SiO2 nanoparticles fabricated by a seed growth method
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DOI：
10.1039/c6nj00161k
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发表时间：
2016-08-01
影响因子：
3.3
通讯作者：
Kawai, Takeshi
中科院分区：
文献类型：
--
作者：
Imura, Clara-Morita;Mori, Takuya;Kawai, Takeshi
晶种生长方法可用于制备各种形状可控的纳米晶体，如棒状、立方状和片状。种子生长方法通常使用分散在溶液中的种子纳米晶和具有选择性吸附性能的封顶剂。本文描述了一种新的种子生长方法，该方法将金纳米颗粒负载在直径为160 nm的SiO_2纳米颗粒(SiO_2@Au纳米颗粒)和具有选择性吸附性能的长链氨基胺衍生物(C18AA)上。在SiO_2@Au纳米颗粒表面有选择性地生长树枝状Au纳米线(Au-DNW)，而在裸SiO_2纳米颗粒表面没有观察到Au纳米晶的生长。这种方法的缺点是制备时间长，产率较低，为此，使用了助还原剂来提高Au DNW的形成速度。我们发现，使用还原能力较弱的抗坏血酸，可以显著提高SiO_2@Au纳米粒子的制备时间和产率。此外，与未负载的Au DNW相比，这些SiO_2@Au DNW具有较高的形态和分散稳定性，有望成为制备具有高形态和分散稳定性的负载型可控纳米晶的方法。
Seed growth methods are useful for the preparation of various shape-controlled nanocrystals, such as rods, cubes, and plates. The seed growth method generally employs seed nanocrystals dispersed in solutions and capping agents with selective adsorption properties. This article describes a novel seed growth method using Au nanoparticles supported on SiO2 nanoparticles with a diameter of 160 nm (SiO2@Au NPs) and a long-chain amidoamine derivative (C18AA) with selective adsorption properties on gold. The selective growth of dendritic Au nanowires (Au DNWs) on the SiO2@Au NPs took place, but growth of Au nanocrystals was not observed using bare SiO2 NPs. The disadvantages of this method were a long time-consuming preparation and a lower yield of SiO2@Au DNWs; for this reason, a co-reducing agent was used to increase the formation rate of Au DNWs. We found that the use of ascorbic acid, which has weak reducing powers, brought a considerable improvement to the preparation time and yield of SiO2@Au DNWs. Furthermore, these SiO2@Au DNWs showed high morphological and dispersion stabilities compared with unsupported Au DNWs, and this method is expected to be the preparation method of supported shape-controlled nanocrystals with high morphological and dispersion stabilities.