Department of Chemistry, University of California, Riverside, California 92521, USA.
J Am Chem Soc. 2010 Dec 8;132(48):17316-24. doi: 10.1021/ja108186w. Epub 2010 Nov 16.
A one-pot solution process has been devised to synthesize colloidal Bi2Te3-Te heterogeneous nanostructures (HNs) that comprise Bi2Te3 nanoplates and Te nanorods. By controlling the reaction kinetics, the reaction of TeO3(2-) and Bi(3+) in the presence of hydrazine first produces uniform Te nanorods and then grows Bi2Te3 nanoplates on the tips and surfaces of these Te nanorods, forming various shapes including "nails", "barbells", "syringes", and "accordions". The specific topological arrangement realized arises from the peculiar anisotropic reactivity of the first formed Te nanorods, whose tips are subsequently exploited to seed the heterogeneous nucleation of Bi2Te3 as enabled by the similar crystal structure and the small lattice mismatch between Te and Bi2Te3. Three important processes, heterogeneous nucleation of Bi2Te3 on the tips and/or surface of Te nanorods, homogeneous nucleation of Bi2Te3, and the direct reaction of a Bi precursor and Te nanorods to form hollow structures via the Kirkendall Effect, occur under various conditions. The manipulation of these processes provides a robust means for the fine shape control of Bi2Te3-Te HNs. It is envisioned that the tailored synthesis of Bi2Te3-Te HNs may promise unique opportunities for producing thermoelectric materials with greatly enhanced performance.
已经设计出一种一锅法合成胶体 Bi2Te3-Te 异质纳米结构 (HNs) 的方法，该结构由 Bi2Te3 纳米板和 Te 纳米棒组成。通过控制反应动力学，在肼的存在下 TeO3(2-) 和 Bi(3+) 的反应首先产生均匀的 Te 纳米棒，然后在这些 Te 纳米棒的尖端和表面上生长 Bi2Te3 纳米板，形成各种形状，包括“钉子”、“杠铃”、“注射器”和“手风琴”。实现的特定拓扑排列源于最初形成的 Te 纳米棒的特殊各向异性反应性，其尖端随后被利用来实现 Bi2Te3 的异质成核，这得益于相似的晶体结构和 Te 与 Bi2Te3 之间的小晶格失配。在各种条件下，发生三个重要过程：Bi2Te3 在 Te 纳米棒的尖端和/或表面上的异质成核、Bi2Te3 的均相成核以及通过 Kirkendall 效应由 Bi 前体和 Te 纳米棒直接反应形成中空结构。这些过程的操纵为 Bi2Te3-Te HNs 的精细形状控制提供了一种稳健的手段。可以预见，定制合成 Bi2Te3-Te HNs 可能为生产具有大大增强性能的热电材料提供独特的机会。
