Direct Observation of Interfacial Au Atoms on TiO2 in Three Dimensions

Wenpei Gao, Shankar Sivaramakrishnan, Jianguo Wen, Jian Min Zuo

Research output: Contribution to journalArticlepeer-review

Abstract

Interfacial atoms, which result from interactions between the metal nanoparticles and support, have a large impact on the physical and chemical properties of nanoparticles. However, they are difficult to observe; the lack of knowledge has been a major obstacle toward unraveling their role in chemical transformations. Here we report conclusive evidence of interfacial Au atoms formed on the rutile (TiO2) (110) surfaces by activation using high-temperature (∼500°C) annealing in air. Three-dimensional imaging was performed using depth-sectioning enabled by aberration-corrected scanning transmission electron microscopy. Results show that the interface between Au nanocrystals and TiO2 (110) surfaces consists of a single atomic layer with Au atoms embedded inside Ti-O. The number of interfacial Au atoms is estimated from ∼1-8 in an interfacial atomic column. Direct impact of interfacial Au atoms is observed on an enhanced Au-TiO2 interaction and the reduction of surface TiO2; both are critical to Au catalysis.

Original languageEnglish (US)
Pages (from-to)2548-2554
Number of pages7
JournalNano letters
Volume15
Issue number4
DOIs
StatePublished - Apr 8 2015

Keywords

  • Au/TiO interface
  • aberration correction
  • catalyst
  • depth sectioning
  • gold nanocrystal
  • interfacial atoms
  • scanning transmission electron microscopy
  • three-dimension

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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