Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA.
J Am Chem Soc. 2013 May 1;135(17):6669-76. doi: 10.1021/ja402240m. Epub 2013 Apr 22.
Prior investigations into the synthesis of colloidal CdSe nanocrystals with a wurtzite crystal structure (wz-CdSe) have given rise to well-developed methods for producing particles with anisotropic shapes such as rods, tetrapods, and wires; however, the synthesis of other shapes has proved challenging. Here we present a seed-mediated approach for the growth of colloidal, shape-controlled wz-CdSe nanoparticles with previously unobserved morphologies. The synthesis, which makes use of small (2-3 nm) wz-CdSe nanocrystals as nucleation sites for subsequent growth, can be tuned to selectively yield colloidal wz-CdSe nanocubes and hexagonal nanoplatelets in addition to nanorod and bullet-shaped particles. We thoroughly characterize the morphology and crystal structures of these new shapes, as well as discuss possible growth mechanisms in the context of control over surface chemistry and the nucleation stage.
先前对具有纤锌矿晶体结构（wz-CdSe）的胶体 CdSe 纳米晶体的合成研究已经提出了许多用于制备具有各向异性形状的颗粒的成熟方法，例如棒、四足和线；然而，其他形状的合成一直具有挑战性。在这里，我们提出了一种种子介导的方法，用于生长具有以前未观察到的形态的胶体、形状可控的 wz-CdSe 纳米粒子。该合成利用小（2-3nm）的 wz-CdSe 纳米晶体作为随后生长的成核点，可以进行调谐，以选择性地得到胶体 wz-CdSe 纳米立方体和六方纳米薄片，以及纳米棒和子弹形颗粒。我们彻底表征了这些新形状的形态和晶体结构，并讨论了在控制表面化学和成核阶段的情况下可能的生长机制。
