Atomic-scale determination of surface facets in gold nanorods

Bart Goris,Luis M Liz-Marzán,Sara Bals,Wouter Van Den Broek,Gustaaf Van Tendeloo,Enrique Carbó-Argibay,Sergio Gómez-Graña

doi:10.1038/nmat3462

Bart Goris, Luis M Liz-Marzán + Show 5 more

Open Access

https://doi.org/10.1038/nmat3462

Copy DOI

Abstract

It is widely accepted that the physical properties of nanostructures depend on the type of surface facets. For Au nanorods, the surface facets have a major influence on crucial effects such as reactivity and ligand adsorption and there has been controversy regarding facet indexing. Aberration-corrected electron microscopy is the ideal technique to study the atomic structure of nanomaterials. However, these images correspond to two-dimensional (2D) projections of 3D nano-objects, leading to an incomplete characterization. Recently, much progress was achieved in the field of atomic-resolution electron tomography, but it is still far from being a routinely used technique. Here we propose a methodology to measure the 3D atomic structure of free-standing nanoparticles, which we apply to characterize the surface facets of Au nanorods. This methodology is applicable to a broad range of nanocrystals, leading to unique insights concerning the connection between the structure and properties of nanostructures.

Highlights

It is widely accepted that the physical properties of nanostructures depend on the type of surface facets[1,2]
On the basis of a limited number of HAADF-STEM projection images, a highquality 3D reconstruction of the atomic structure is obtained without the use of any prior knowledge
We investigated Au nanorods, obtained by seed-mediated growth in aqueous solution, assisted by the surfactant cetyltrimethylammonium bromide (CTAB) and Ag+ ions[16]

Summary

Introduction

It is widely accepted that the physical properties of nanostructures depend on the type of surface facets[1,2]. We propose a compressive-sensing-based 3D reconstruction algorithm, which enables us to completely characterize the 3D atomic lattice of free-standing Au nanorods. On the basis of a limited number of HAADF-STEM projection images, a highquality 3D reconstruction of the atomic structure is obtained without the use of any prior knowledge.

Results

Conclusion