Effect of Gold Nanoparticles on Photoexcited Charge Carriers in Powdered TiO2鈭扡ong Range Quenching of Photoluminescence

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• 作者：Ana Stevanovic ; Shiliang Ma ; John T. Yates ; Jr.
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 11, 2014
• 年：2014
• 卷：118
• 期：36
• 页码：21275-21280
• 全文大小：295K
• ISSN：1932-7455

文摘

Photoluminescence spectroscopy was employed to study the photoinduced charge transfer between TiO₂ nanoparticles and Au nanoparticles under vacuum. We found that small coverages of 3 nm Au nanoparticles deposited on TiO₂ significantly diminish the 540 nm (2.3 eV) photoluminescence emission from TiO₂ because of the redistribution of the photoexcited charge to Au nanoparticles that are capable of accepting negative charges behind the Schottky barrier. The lack of development of the photoluminescence emission of Au/TiO₂ during continuous UV irradiation occurs because of a short circuit established through Au nanoparticles in which transferred electrons in Au recombine nonradiatively with holes in TiO₂. The photoexcited electron transfer from TiO₂ to the Au nanoparticles occurs beyond the Au particle perimeter over a distance of at least 4 nm. The quenching of photoluminescence by resonance energy transfer from TiO₂ to Au nanoparticles is unimportant as Au plasmonic absorption is not observed.