Bromide Causes Facet-Selective Atomic Addition in Gold Nanorod Syntheses
Bromide Causes Facet-Selective Atomic Addition in Gold Nanorod Syntheses
复制标题
DOI：
10.1021/acs.chemmater.0c01494
复制
发表时间：
2020-08-11
影响因子：
8.6
通讯作者：
Wiley, Benjamin J.
中科院分区：
文献类型：
--
作者：
Brown, Micah;Wiley, Benjamin J.
金纳米棒的长径比相关特性被广泛应用，但各向异性纳米棒生长的原因尚不清楚。收集了利用单晶电极进行的测量，以确定五绕金纳米棒合成中的哪种添加剂(S)负责小面选择原子加成。在不加溴的情况下，十六烷基三甲基铵对Au(100)和Au(111)单晶的原子加成速率相同，得到各向同性的纳米粒子。随着溴化物浓度的增加，Au(100)相对于Au(111)的原子加成速率降低，金纳米棒的长径比增大。在没有十六烷基三甲基铵存在的情况下，溴化物是Au(100)更有效的钝化剂，表明十六烷基三甲基铵不会引起原子的面选择性加成。十六烷基三甲基铵表面活性剂仍然是金纳米棒生长所必需的，因为它降低了金离子还原的速度，并稳定了悬浮纳米粒子的聚集。
The aspect ratio-dependent properties of gold nanorods are used in a variety of applications, but the cause of anisotropic nanorod growth remains unclear. Measurements utilizing single-crystal electrodes were collected to determine what additive(s) in pentatwinned gold nanorod syntheses are responsible for facet-selective atomic addition. With cetyltrimethylammonium in the absence of bromide, the rate of atomic addition to Au(100) and Au(111) single crystals was the same, and isotropic nanoparticles were produced. The addition of increasing concentrations of bromide suppressed the rate of atomic addition to Au(100) relative to Au(111) and increased the aspect ratio of gold nanorods. Bromide was a more effective passivator of Au(100) in the absence of cetyltrimethylammonium, indicating cetyltrimethylammonium does not cause facet-selective atomic addition. Cetyltrimethylammonium surfactant is still necessary for gold nanorod growth because it reduces the rate of gold ion reduction and stabilizes suspended nanoparticles against aggregation.