Department of Chemistry, Ajou University, Suwon 16499, Korea.
Department of Chemistry, KAIST, Daejeon 34141, Korea.
Nanoscale. 2019 Oct 7;11(37):17436-17443. doi: 10.1039/c9nr04422a. Epub 2019 Sep 18.
Epitaxially aligned large silver (Ag) nanoplate arrays with ultraclean surfaces are very attractive for novel plasmonic applications. Although solution-phase methods have been extensively employed to synthesize Ag nanoplates, these cannot be used to grow epitaxial large Ag nanoplates on substrates. Here we report a vapor-phase synthetic strategy to epitaxially grow submillimeter-scale Ag nanoplates on a variety of substrates. By simply transporting Ag vapor to the substrates at an optimal temperature (820 °C), we synthesize ∼100 μm-sized Ag nanoplates with atomically clean surfaces, which are three-dimensionally aligned on the substrates. We demonstrate that both the type of supported seed and their interfacial lattice matching with the substrates determine the epitaxial growth habit of the nanoplates, directing their crystallinity, shape, and orientation. (i) On r-cut sapphire substrates, twinned pentagonal nanoplates grow vertically from twinned triangular seeds through a seed → nanoplate process. (ii) On m-cut sapphire substrates, twinned trapezoidal Ag nanoplates grow slantingly from twinned decahedral seeds through a seed → NW → nanoplate process. (iii) Interestingly, twin-free single-crystalline trapezoidal Ag nanoplates grow from twin-free square pyramidal seeds on STO (001) substrates through a seed → NW → nanoplate process. The epitaxially aligned Ag nanoplate arrays could serve as a new platform for two-dimensional (2D) guiding of surface plasmons as well as for hierarchical 3D plasmonic nanoarchitecturing.
具有超洁净表面的外延取向大尺寸银（Ag）纳米板阵列对于新型等离子体应用非常有吸引力。尽管已经广泛采用溶液相方法来合成 Ag 纳米板，但这些方法不能用于在基底上生长外延取向的大尺寸 Ag 纳米板。在这里，我们报告了一种气相合成策略，用于在各种基底上外延生长亚毫米级的 Ag 纳米板。通过将 Ag 蒸气简单地输送到最佳温度（820°C）的基底上，我们合成了具有原子洁净表面的~100 μm 大小的 Ag 纳米板，这些纳米板在基底上呈三维取向排列。我们证明了支撑种子的类型及其与基底的界面晶格匹配决定了纳米板的外延生长习性，从而控制了它们的结晶度、形状和取向。（i）在 r 切蓝宝石衬底上，孪晶五边形纳米板通过种子→纳米板过程从孪晶三角形种子垂直生长。（ii）在 m 切蓝宝石衬底上，孪晶梯形 Ag 纳米板通过种子→NW→纳米板过程从孪晶十面体种子倾斜生长。（iii）有趣的是，在 STO（001）衬底上，无孪晶的单晶梯形 Ag 纳米板从无孪晶的四方锥形种子通过种子→NW→纳米板过程生长。外延取向的 Ag 纳米板阵列可作为二维（2D）表面等离激元引导以及分层 3D 等离子体纳米结构的新平台。
