Colloidal Synthesis of Nanohelices via Bilayer Lattice Misfit
Colloidal Synthesis of Nanohelices via Bilayer Lattice Misfit
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DOI：
10.1021/jacs.0c05175
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发表时间：
2020-07-22
影响因子：
15
通讯作者：
Ye, Xingchen
中科院分区：
文献类型：
--
作者：
Liu, Yang;Li, Yuda;Ye, Xingchen
螺旋结构在多种长度尺度的天然和合成材料中普遍存在。先前已经在这种对称破缺形状中证明了优异且有时不寻常的手性光学、机械和传感特性，但通过胶体合成实现亚100纳米尺度螺旋结构的一般原理仍未得到充分探索。在这项工作中，我们描述了基于氧化钆（Gd2O3）的单分散纳米螺旋的湿化学合成。像差校正电子显微镜显示，单个纳米螺旋由双层结构组成，外层和内层分别源自块体 Gd2O3 的 {111} 和 {100} 平面。与具有灵活弯曲几何形状的现有无机纳米线圈不同，两个相邻晶面之间的内置晶格失配诱导连续螺旋生长，产生三维刚性纳米螺旋。此外，发现反应中水的存在抑制纳米螺旋的形成，产生主要表达{111}平面的纳米板。我们的研究不仅提供了自下而上的合成路线和对纳米螺旋形成的机制理解，而且还可能为创建手性等离子体纳米结构、发光生物标签和纳米级传感器开辟新的可能性。
Helical structures are ubiquitous in natural and synthetic materials across multiple length scales. Excellent and sometimes unusual chiral optical, mechanical, and sensing properties have been previously demonstrated in such symmetry-breaking shape, yet a general principle to realize helical structures at the sub100 nm scale via colloidal synthesis remains underexplored. In this work, we describe the wet-chemical synthesis of monodisperse nanohelices based on gadolinium oxide (Gd2O3). Aberration-corrected electron microscopy revealed that individual nanohelices consist of a bilayer structure with the outer and inner layers derived from the {111} and {100} planes of bulk Gd2O3, respectively. Distinct from existing inorganic nanocoils with flexible bending geometries, the built-in lattice misfit between two adjacent crystal planes induces continuous helical growth yielding three-dimensional rigid nanohelices. Furthermore, the presence of water in the reaction was found to suppress the formation of nanohelices, producing nanoplates expressing predominantly {111} planes. Our study not only provides a bottom-up synthetic route and mechanistic understanding of nanohelices formation but may also open up new possibilities for creating chiral plasmonic nanostructures, luminescent biological labels, and nanoscale transducers.