Title

Nano-Gold Diggers: Au-Assisted Sio2-Decomposition And Desorption In Supported Nanocatalysts

Keywords

AFM; atomic force microscopy; Au; nanoparticle; NP-support interaction; Si; SiO 2; X-ray photoelectron spectroscopy; XPS

Abstract

An investigation of the thermal stability of size-selected Au nanoparticles (NPs) synthesized via inverse micelle encapsulation and deposited on SiO 2(4 nm)/Si(100) is presented. The size and mobility of individual Au NPs after annealing at elevated temperatures in ultrahigh vacuum (UHV) was monitored via atomic force microscopy (AFM). An enhanced thermal stability against coarsening and lack of NP mobility was observed up to 1343 K. In addition, a drastic decrease in the average NP height was detected with increasing annealing temperature, which was not accompanied by the sublimation of Au atoms/clusters in UHV. The apparent decrease in the Au NP height observed is assigned to their ability to dig vertical channels in the underlying SiO 2 support. More specifically, a progressive reduction in the thickness of the SiO2 support underneath and in the immediate vicinity of the NPs was evidenced, leading to NPs partially sinking into the SiO2 substrate. The complete removal of silicon oxide in small patches was observed to take place around the Au NPs after annealing at 1343 K in UHV. These results reveal a Au-assisted oxygen desorption from the support via reverse oxygen spillover to the NPs. © 2013 American Chemical Society.

Publication Date

11-26-2013

Publication Title

ACS Nano

Volume

7

Issue

11

Number of Pages

10327-10334

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/nn404744b

Socpus ID

84888876733 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84888876733

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