Faceted Gold Nanorods: Nanocuboids, Convex Nanocuboids, And Concave Nanocuboids

Keywords

Au nanorods; High-index facets; Localized plasmon resonances; Low-index facets; Nanocatalysis; Surface-enhanced Raman scattering

Abstract

Au nanorods are optically tunable anisotropic nanoparticles with built-in catalytic activities. The state-of-the-art seed-mediated nanorod synthesis offers excellent control over the aspect ratios of cylindrical Au nanorods, which enables fine-tuning of plasmon resonances over a broad spectral range. However, facet control of Au nanorods with atomic-level precision remains significantly more challenging. The coexistence of various types of low-index and high-index facets on the highly curved nanorod surfaces makes it extremely challenging to quantitatively elucidate the atomic-level structure-property relationships that underpin the catalytic competence of Au nanorods. Here we demonstrate that cylindrical Au nanorods undergo controlled facet evolution during their overgrowth in the presence of Cu2+ and cationic surfactants, resulting in the formation of anisotropic nanostructures enclosed by well-defined facets, such as low-index faceting nanocuboids and high-index faceting convex nanocuboids and concave nanocuboids. These faceted Au nanorods exhibit enriched optical extinction spectral features, broader plasmonic tuning range, and enhanced catalytic tunability in comparison to the conventional cylindrical Au nanorods. The capabilities to both fine-tailor the facets and fine-tune the plasmon resonances of anisotropic Au nanoparticles open up unique opportunities for us to study, in great detail, the facet-dependent interfacial molecular transformations on Au nanocatalysts using surface-enhanced Raman scattering as a time-resolved spectroscopic tool. (Figure Presented).

Publication Date

6-10-2015

Publication Title

Nano Letters

Volume

15

Issue

6

Number of Pages

4161-4169

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/acs.nanolett.5b01286

Socpus ID

84935896519 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84935896519

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