Sequential Cation Exchange in Nanocrystals: Preservation of Crystal Phase and Formation of Metastable Phases

被引：294

作者：

Li, Hongbo ^{[1
]}

Zanella, Marco ^{[1
]}

Genovese, Alessandro ^{[1
]}

Povia, Mauro ^{[1
]}

Falqui, Andrea ^{[1
]}

Giannini, Cinzia ^{[2
]}

Manna, Liberato ^{[1
]}

机构：

[1] Ist Italiano Tecnol, I-16163 Genoa, Italy

[2] CNR Ist Crystallog IC, I-70126 Bari, Italy

来源：

NANO LETTERS | 2011年 / 11卷 / 11期

基金：

欧洲研究理事会;

关键词：

Cation exchange; nanocrystals; copper selenide; ZnSe; metastable phases; semiconductors; QUANTUM DOTS SYNTHESIS; COLLOIDAL NANOCRYSTALS; HETEROSTRUCTURED NANOCRYSTALS; FACILE SYNTHESIS; SIZE; CORE/SHELL; CLUSTERS; SELENIDE; GROWTH; SE;

D O I：

10.1021/nl202927a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We demonstrate that it is possible to convert CdSe nanocrystals of a given size, shape (either spherical or rod shaped), and crystal structure (either hexagonal wurtzite, i.e., hexagonal close packed (hcp), or cubic sphalerite, i.e., face-centered cubic (fcc)), into ZnSe nanocrystals that preserve all these characteristics of the starting particles (i.e., size, shape, and crystal structure), via a sequence of two cation exchange reactions, namely, Cd2+ -> Cu+ -> Zn2+. When starting from hexagonal wurtzite CdSe nanocrystals, the exchange of Cd2+ with Cu+ yields Cu2Se nanocrystals in a metastable hexagonal phase, of which we could follow the transformation to the more stable fcc phase for a single nanorod, under the electron microscope. Remarkably, these metastable hcp Cu2Se nanocrystals can be converted in solution into ZnSe nanocrystals, which yields ZnSe nanocrystals in a pure hcp phase.

引用

页码：4964 / 4970

页数：7

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[1] Cation exchange: A simple and versatile route to inorganic colloidal spheres with the same size but different compositions and properties [J].