Electrochemical templating of metal nanoparticles and nanowires on single-walled carbon nanotube networks
Electrochemical templating of metal nanoparticles and nanowires on single-walled carbon nanotube networks
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DOI：
10.1021/ja051320r
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发表时间：
2005-08-03
影响因子：
15
通讯作者：
Macpherson, JV
中科院分区：
文献类型：
--
作者：
Day, TM;Unwin, PR;Macpherson, JV
描述了使用单壁碳纳米管（SWNT）网络作为金属（Ag和Pt）纳米结构的电沉积的模板。原始的单壁碳纳米管，生长在绝缘二氧化硅表面使用催化化学气相沉积，作为工作电极。在最简单的情况下，通过在SWNT衬底上沉积金条来实现电接触（器件1）。Ag和Pt在长时间（30 s）内的沉积导致单壁碳纳米管上的颗粒的高密度，从Au/单壁碳纳米管边界移动到离接触更远距离处的孤立纳米颗粒的几乎连续的纳米线形成。对于Ag和Pt成核的直接电化学研究，将组件涂覆在抗蚀剂层中，并且打开小窗口以仅将电连接的SWNT暴露于溶液（装置2）。在这种情况下，金属沉积的伏安法和安培法研究中的电化学特征仅归因于单壁碳纳米管的过程。再加上高分辨率的显微镜测量（原子力显微镜和场发射扫描电子显微镜），这种方法提供了详细的成核和生长机制的银和铂单壁碳纳米管电化学控制下。特别是，银生长被发现是快速和渐进的纳米粒子密度随时间的推移而增加，而铂沉积的特征在于较低的成核密度和较慢的生长速率与较大的颗粒的趋势，以产生在很长一段时间。
The use of single-walled carbon nanotube (SWNT) networks as templates for the electrodeposition of metal (Ag and Pt) nanostructures is described. Pristine SWNTs, grown on insulating SiO2 surfaces using catalyzed chemical vapor deposition, served as the working electrode. In the simplest case, electrical contact was made by depositing a gold strip on the SWNT substrate (device 1). Deposition of Ag and Pt over extensive periods (30 s) resulted in a high density of particles on the SWNTs, with almost contiguous nanowire formation from the Au/SWNT boundary moving to isolated nanoparticles at further distances from the contact. For direct electrochemical studies of Ag and Pt nucleation, the assembly was coated in a resist layer and a small window opened up to expose only the electrically connected SWNTs to solution (device 2). In this case, the electrochemical signature in voltammetric and amperometric studies of metal deposition was due solely to processes at the SWNTs. Coupled with high-resolution microscopy measurements (atomic force microscopy and field emission scanning electron microscopy), this approach provided detail on the nucleation and growth mechanisms of Ag and Pt on SWNTs under electrochemical control. In particular, Ag growth was found to be rapid and progressive with an increasing nanoparticle density with time, whereas Pt deposition was characterized by lower nucleation densities and slower growth rates with a tendency for larger particles to be produced over long times.