Department of Chemistry, University of Louisville , Louisville, Kentucky 40292, United States.
ACS Nano. 2015 Oct 27;9(10):10278-86. doi: 10.1021/acsnano.5b04280. Epub 2015 Sep 15.
Here we describe the electrodeposition of Ag in the presence of cetyltrimethylammonium bromide (CTAB) onto 5 μm gap Au interdigitated array (IDA) electrodes that are bare, thiol-functionalized, or thiol-functionalized and seeded with 4 nm diameter Au nanoparticles (NPs). After deposition, applying a voltage between 5 and 10 V in air for 0 to 1000 s resulted in one-dimensional (1D) Ag NP chains spanning across the IDA gap. The Ag NP chains form on IDAs functionalized with thiols and Au NP-seeded at about 5 V and at 10 V for the other nonseeded surfaces. Ag NP chains do not form at all up to 10 V when IDAs are treated with ozone or water soaking to remove possible CTA(+) ions from the surface, when Ag deposition takes place in the absence of CTAB, or when the voltage is applied under dry N2 (low humidity). Chain formation occurs by Ag moving from the positive to negative electrode. Coating the devices with a negatively charged surfactant, sodium dodecyl sulfate, also results in Ag NP chains by Ag moving from the positive to the negative electrodes, which confirms that the chains form by electrochemical oxidation at the positive electrode and deposition at the negative electrode. The surfactant ions and thin layer of water present in the humid environment facilitate this electrochemical process.
在这里，我们描述了在十六烷基三甲基溴化铵（CTAB）存在下，将银沉积在 5 μm 间隙金叉指电极（IDA）上的过程，这些电极可以是裸露的、巯基功能化的或巯基功能化并接种了 4nm 直径的金纳米颗粒（NPs）。沉积后，在空气中施加 5 至 10V 的电压，持续 0 至 1000s，导致一维（1D）Ag NP 链跨越 IDA 间隙。在巯基功能化的 IDA 上，Ag NP 链在约 5V 和 10V 下形成，而其他未接种的表面则在 10V 下形成。当 IDA 用臭氧或水浸泡处理以去除表面可能的 CTA(+)离子、在没有 CTAB 的情况下进行 Ag 沉积或在干燥氮气（低湿度）下施加电压时，Ag NP 链根本不会形成。链的形成是通过 Ag 从正极向负极移动实现的。在器件上涂覆带负电荷的表面活性剂十二烷基硫酸钠（SDS）也会导致 Ag NP 链的形成，这是因为 Ag 从正极向负极移动，证实了链的形成是通过正极的电化学氧化和负极的沉积实现的。在潮湿环境中存在的表面活性剂离子和薄水层促进了这个电化学过程。
