2019年4月
Doping of Nb5+ Species at the Au-TiO<inf>2</inf> Interface for Plasmonic Photocatalysis Enhancement
Langmuir
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- 巻
- 35
- 号
- 16
- 開始ページ
- 5455
- 終了ページ
- 5462
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/acs.langmuir.8b04075
© 2019 American Chemical Society. Au nanoparticles loaded on semiconductor TiO2 absorb visible light due to their surface plasmon resonance (SPR) and inject the photogenerated hot electrons (ehot-) into the conduction band of TiO2. The separated charges promote oxidation and reduction reactions. The step that determines the rate of the plasmonic photocatalysis on the Au/TiO2 system is the ehot- injection through the Schottky barrier created at the Au-TiO2 interface. In the present work, niobium (Nb5+) oxide species were doped at the Au-TiO2 interface by loading Nb5+ onto the TiO2 surface followed by deposition of Au particles (2 wt % of TiO2). Visible light irradiation of the Au/Nb5+/TiO2 catalysts promotes aerobic oxidation of alcohols with much higher efficiency than that of undoped Au/TiO2. Lewis acidity of the Nb5+ species located at the interface cancels the negative charges of Au and creates a barrier with a narrower depletion layer, promoting tunneling ehot- injection. Efficiency of the ehot- injection depends on the amount of Nb5+ doped. Loading small amounts of Nb5+ (0.1 wt % of TiO2) creates mononuclear NbO4 species and shows large activity enhancement. In contrast, loading larger amounts of Nb5+ creates aggregated polynuclear Nb2O5 species. They decrease the electron density of Au particles and weaken their SPR absorption. This suppresses the ehot- generation on the Au particles and decreases the activity of plasmonic photocatalysis.
- リンク情報
- ID情報
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- DOI : 10.1021/acs.langmuir.8b04075
- ISSN : 0743-7463
- eISSN : 1520-5827
- PubMed ID : 30916561
- SCOPUS ID : 85065112472