Williams, OBJ;
Katsiev, K;
Baek, B;
Harrison, G;
Thornton, G;
Idriss, H;
(2022)
Direct Visualization of a Gold Nanoparticle Electron Trapping Effect.
Journal of the American Chemical Society
, 144
(2)
pp. 1034-1044.
10.1021/jacs.1c12197.
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Abstract
A new atomic-scale anisotropy in the photoreaction of surface carboxylates on rutile TiO2(110) induced by gold clusters is found. STM and DFT+U are used to study this phenomenon by monitoring the photoreaction of a prototype hole-scavenger molecule, benzoic acid, over stoichiometric (s) s-TiO2, Au9/s-TiO2, and reduced (r) Au9/r-TiO2. STM results show that benzoic acid adsorption displaces a large fraction of Au clusters from the terraces toward their edges. DFT calculations explain that Au9 clusters on stoichiometric TiO2 are distorted by benzoic acid adsorption. The influence of sub-monolayers of Au on the UV/visible photoreaction of benzoic acid was explored at room temperature, with adsorbate depletion taken as a measure of activity. The empty sites, observed upon photoexcitation, occurred in elongated chains (2 to 6 molecules long) in the [11̅0] and [001] directions. A roughly 3-fold higher depletion rate is observed in the [001] direction. This is linked to the anisotropic conduction of excited electrons along [001], with subsequent trapping by Au clusters leaving a higher concentration of holes and thus an increased decomposition rate. To our knowledge this is the first time that atomic-scale directionality of a chemical reaction is reported upon photoexcitation of the semiconductor.
Type: | Article |
---|---|
Title: | Direct Visualization of a Gold Nanoparticle Electron Trapping Effect |
Location: | United States |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1021/jacs.1c12197 |
Publisher version: | https://doi.org/10.1021/jacs.1c12197 |
Language: | English |
Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | Adsorption, Diffusion, Gold, Metal clusters, Oxides |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
URI: | https://discovery.ucl.ac.uk/id/eprint/10141905 |
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