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Shape adjustment between multiply twinned and single-crystalline polyhedral gold nanocrystals: Decahedra, icosahedra, and truncated tetrahedra

Seo, Daeha and Il Yoo, Choong and Chung, Im Sik and Park, Seung Min and Ryu, Seol and Song, Hyunjoon (2008) Shape adjustment between multiply twinned and single-crystalline polyhedral gold nanocrystals: Decahedra, icosahedra, and truncated tetrahedra. JOURNAL OF PHYSICAL CHEMISTRY C, 112 (7). pp. 2469-2475.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/jp7109498

Abstract

Polyhedral gold nanocrystals with decahedral, icosahedral, and truncated tetrahedral shapes are synthesized by a simple one-pot polyol process in the prescence of poly(vinyl pyrrolidone) (PVP). High PVP concentration up to 360 equiv of the gold precursor, HAuCl4, effectively stabilizes decahedral seeds to yield uniform decahedra with various edge sizes. Decreased PVP concentration subsequently leads to selective formation of icosahedra and truncated tetrahedra. This results from a combination between the relative energy difference of the polyhedral structures and the oxidative etching rate of the seeds by Cl-/O-2 during the reaction. The distinct morphologies of gold natiocrystals exhibit characteristic extinction patterns in the UV-vis-NIR ranges, and these properties are successfully analyzed by the discrete dipole approximation (DDA) calculation. Most extinctions stem from the polar and azimuthal dipolar excitations, and azimuthal quardrupole resonance appears between two dipolar bands in the 88-nm decahedra. Given these shape- and size-dependent optical properties, gold nanocrystals hold considerable promise for biomedical and photonic applications.

Item Type:Article
Subjects:Material Science > Functional and hybrid materials
Physical Science > Photonics
ID Code:1851
Deposited By:Farnush Anwar
Deposited On:16 Dec 2008 14:36
Last Modified:12 Jan 2009 12:02

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