Habas Susan E, Lee Hyunjoo, Radmilovic Velimir, Somorjai Gabor A, Yang Peidong
Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA.
Nat Mater. 2007 Sep;6(9):692-7. doi: 10.1038/nmat1957. Epub 2007 Jul 8.
Morphological control of nanocrystals has become increasingly important, as many of their physical and chemical properties are highly shape dependent. Nanocrystal shape control for both single- and multiple-material systems, however, remains empirical and challenging. New methods need to be explored for the rational synthetic design of heterostructures with controlled morphology. Overgrowth of a different material on well-faceted seeds, for example, allows for the use of the defined seed morphology to control nucleation and growth of the secondary structure. Here, we have used highly faceted cubic Pt seeds to direct the epitaxial overgrowth of a secondary metal. We demonstrate this concept with lattice-matched Pd to produce conformal shape-controlled core-shell particles, and then extend it to lattice-mismatched Au to give anisotropic growth. Seeding with faceted nanocrystals may have significant potential towards the development of shape-controlled heterostructures with defined interfaces.
纳米晶体的形态控制变得越来越重要，因为它们的许多物理和化学性质高度依赖于形状。然而，对于单材料和多材料系统的纳米晶体形状控制仍然是经验性的且具有挑战性。需要探索新的方法来合理地合成设计具有可控形态的异质结构。例如，在具有良好晶面的种子上生长不同的材料，可以利用定义好的种子形态来控制二级结构的成核和生长。在这里，我们使用了具有高度晶面的立方铂种子来引导二级金属的外延生长。我们用晶格匹配的钯来证明这一概念，以生产形状可控的共形核壳颗粒，然后将其扩展到晶格不匹配的金，以实现各向异性生长。用有晶面的纳米晶体作为种子对于开发具有明确界面的形状可控异质结构可能具有巨大潜力。
