دانلود مقاله ترجمه شده رشد اپیتاکسی نانو کریستال های فلزی ناهمگن: از نانو ذرات هشت وجهی طلا تا پالادیوم و نانو مکعب های نقره

Abstract

The construction of functional noble metal nanocrystals has received increasing interest because their unique optical, magnetic, and catalytic properties can be tuned by controlling the size, shape, chemical composition, surface and interfacial structure,^1,2 and they have potential applications such as in catalysis, biodiagnostics, plasmonics, and surface-enhanced Raman spectroscopy.^3,4 Very recently, the special attention has been paid on the shape-controlled synthesis of binary metallic heterostructures through epitaxial growth of second (third) metal over the seed metal.^5–7 As a new and very important achievement, Yang and co-workers rationally designed and used cubic Pt nanocrystals as seeds for the conformal shape-controlled epitaxial overgrowth of Pd and the anisotropic growth of Au.⁸ They also showed that lattice mismatch (0.77% for Pt/Pd versus 4.08% for Pt/Au) plays a critically important role in the overgrowth of the secondary metal and high lattice mismatch prevents the conformal overgrowth. In order to extend the shape controlled growth of binary or trinary metallic nanocrystals and get the deep insight of the growth mechanism, it is highly desirable to develop new synthesis methods and establish a general rule for epitaxial growth of heterostructured nanocrystals of a variety of metals.