Optical Hot Spot Generation by the Plasmonic Coupling of Au Nanoparticles in the Nanospaces of Mesoporous Titanium(IV) Oxide
An in situ reduction technique consisting of chemisorption of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) and subsequent reaction with HAuCl4 has been developed for depositing Au nanoparticles (NPs) uniformly in the depth direction of a mesoporous TiO2 nanocrystalline film (Au/TMCTS/mp-TiO2). The...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 37(2021), 5 vom: 09. Feb., Seite 1838-1842 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | An in situ reduction technique consisting of chemisorption of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) and subsequent reaction with HAuCl4 has been developed for depositing Au nanoparticles (NPs) uniformly in the depth direction of a mesoporous TiO2 nanocrystalline film (Au/TMCTS/mp-TiO2). The TMCTS monolayer is further converted into silicon oxide by heating in the air (Au/SiOx/mp-TiO2). In the absorption spectra of Au/SiOx/mp-TiO2 prepared at varying HAuCl4 concentrations (C), the localized surface plasmon resonance (LSPR) band of Au NPs significantly broadens C ≈ 1.22 mM at 546 nm to be split into two peaks around 500 and 700 nm at C ≥ 2.43 mM, whereas such a phenomenon is not observed for the usual Au NP-loaded TiO2 particles. Three-dimensional-finite difference time domain simulations showed that the unique optical property of Au/SiOx/mp-TiO2 stems from the effective LSPR coupling of very close Au NPs and partial fusions in the nanospaces of mp-TiO2. Further, the optical hot spots in Au/TMCTS/mp-TiO2 as well as Au/SiOx/mp-TiO2 generate an intense local electric field giving increase to a great enhancement of the absorption in the infrared spectrum of the TMCTS monolayer on mp-TiO2 |
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| Beschreibung: | Date Revised 09.02.2021 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.0c03184 |