Manthiram Karthish, Beberwyck Brandon J, Talapin Dmitri V, Alivisatos A Paul
Department of Chemical Engineering, UC Berkeley.
J Vis Exp. 2013 Dec 11(82):e50731. doi: 10.3791/50731.
We demonstrate a method for the synthesis of multicomponent nanostructures consisting of CdS and CdSe with rod and tetrapod morphologies. A seeded synthesis strategy is used in which spherical seeds of CdSe are prepared first using a hot-injection technique. By controlling the crystal structure of the seed to be either wurtzite or zinc-blende, the subsequent hot-injection growth of CdS off of the seed results in either a rod-shaped or tetrapod-shaped nanocrystal, respectively. The phase and morphology of the synthesized nanocrystals are confirmed using X-ray diffraction and transmission electron microscopy, demonstrating that the nanocrystals are phase-pure and have a consistent morphology. The extinction coefficient and quantum yield of the synthesized nanocrystals are calculated using UV-Vis absorption spectroscopy and photoluminescence spectroscopy. The rods and tetrapods exhibit extinction coefficients and quantum yields that are higher than that of the bare seeds. This synthesis demonstrates the precise arrangement of materials that can be achieved at the nanoscale by using a seeded synthetic approach.
我们展示了一种合成由具有棒状和四足形态的硫化镉（CdS）和硒化镉（CdSe）组成的多组分纳米结构的方法。采用了种子合成策略，其中首先使用热注入技术制备硒化镉的球形种子。通过控制种子的晶体结构为纤锌矿或闪锌矿，随后在种子上进行硫化镉的热注入生长分别导致棒状或四足状纳米晶体。使用X射线衍射和透射电子显微镜确认合成纳米晶体的相和形态，表明纳米晶体是相纯的并且具有一致的形态。使用紫外-可见吸收光谱和光致发光光谱计算合成纳米晶体的消光系数和量子产率。棒状和四足状纳米晶体表现出高于裸种子的消光系数和量子产率。这种合成展示了通过使用种子合成方法在纳米尺度上可以实现的材料精确排列。
