Idriss, H;
khan, MA;
Bakr, OM;
Sinatra, L;
Oufi, M;
(2017)
Evidence of Plasmonic Induced Photocatalytic Hydrogen Production on Pd/TiO2 Upon Deposition on Thin Films of Gold.
Catalysis Letters
, 147
(4)
pp. 811-820.
10.1007/s10562-017-1998-4.
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Abstract
H2-production from renewables using sunlight is probably the holy grail of modern science and technology. Among the many approaches for increasing reaction rates, by increasing light absorption, plasmonic materials are often invoked. Yet, most plasmonic metals on semiconductors are also good for Schottky barrier formation. In this work, we are presenting evidences of de-coupling the plasmonic from Schottky effects on photoreaction. To conduct this we have systematically changed the under-layer gold film thickness and associated particle size. On top of the thin film layer, we have deposited the exact amount of a prototypical Schottky-based photo-catalyst (Pd/TiO2). We found up to 4 times increase in the H2-production rate at a critical Au film thickness (8 nm-thick). Below this thickness, the plasmonic response is not too strong while above it, the PR decays in favor of the Drude absorption mode. The reaction requires the presence of both UV (to excite the semiconductor) and visible light (to excite Au particles) in order to obtain high hydrogen production, 800 µmol/gCatal.min (probably the highest direct hydrogen (not current) production rate reported on a performing catalyst). The enhancement origin is quantitatively traced to its computed electric field strength (EFS). Adding a dielectric (SiO2) in between the Au thin layer and the catalyst exponentially decreased the reaction rate and EFS, with increasing its thickness. This work indicates the possibility of making an active and stable photo-catalyst from fundamental concepts yet further progress on the structural (technological) front is needed to make a practical catalyst.
| Type: | Article |
|---|---|
| Title: | Evidence of Plasmonic Induced Photocatalytic Hydrogen Production on Pd/TiO2 Upon Deposition on Thin Films of Gold |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s10562-017-1998-4 |
| Publisher version: | http://dx.doi.org/10.1007/s10562-017-1998-4 |
| Language: | English |
| Additional information: | © The Author(s) 2017. © The Author(s) 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
| Keywords: | Photocatalysis, Hydrogen production, Gold plasmon, Pd/TiO2, Electric field enhancement |
| 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/1543374 |
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