Gilroy K D, Sundar A, Hajfathalian M, Yaghoubzade A, Tan T, Sil D, Borguet E, Hughes R A, Neretina S
College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, USA.
Nanoscale. 2015 Apr 21;7(15):6827-35. doi: 10.1039/c5nr00151j.
Described is a straightforward procedure for forming organized substrate-immobilized nanoprisms which are single crystalline, surfactant-free and which form a heteroepitaxial relationship with the underlying substrate. The devised route utilizes truncated Au octahedrons formed through solid state dewetting techniques as high temperature heterogeneous nucleation sites for Ag adatoms which are arriving to the substrate surface in the vapour phase. Observed is a morphological and compositional transformation of the Au structures to triangular nanoprisms comprised of a homogeneous AuAg alloy. During this transformation, the localized surface plasmon resonance red-shifts, broadens and increases in strength. The shape transformation, which cannot be rationalized using thermodynamic arguments dependent on the surface energy minimization, is described in terms of a kinetically driven growth mode, previously predicted by molecular dynamic simulations. The so-formed structures, when coated with a thin layer of Pd, are demonstrated as plasmonic sensing elements for hydrogen detection.
本文描述了一种形成有组织的、固定在基底上的纳米棱柱的简单方法，这些纳米棱柱是单晶的、无表面活性剂的，并且与下层基底形成异质外延关系。所设计的路线利用通过固态去湿技术形成的截顶金八面体作为银吸附原子的高温异质成核位点，银吸附原子以气相形式到达基底表面。观察到金结构向由均匀金银合金组成的三角形纳米棱柱的形态和成分转变。在这个转变过程中，局部表面等离子体共振发生红移、展宽并增强。这种形状转变不能用依赖于表面能最小化的热力学论据来解释，而是根据动力学驱动的生长模式来描述，该生长模式先前已由分子动力学模拟预测。如此形成的结构，当涂上一层薄钯时，被证明是用于氢气检测的等离子体传感元件。
