Gold鈥揟itanium(IV) Oxide Plasmonic Photocatalysts Prepared by a Colloid-Photodeposition Method: Correlation Between Physical Properties and Photocatalytic Activities

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• 作者：Atsuhiro Tanaka ; Asako Ogino ; Moe Iwaki ; Keiji Hashimoto ; Akira Ohnuma ; Fumiaki Amano ; Bunsho Ohtani ; Hiroshi Kominami
• 刊名：Langmuir
• 出版年：2012
• 出版时间：September 11, 2012
• 年：2012
• 卷：28
• 期：36
• 页码：13105-13111
• 全文大小：427K
• 年卷期：v.28,no.36(September 11, 2012)
• ISSN：1520-5827

文摘

Colloidal gold (Au) nanoparticles were prepared and successfully loaded on titanium(IV) oxide (TiO₂) without change in the original particle size using a method of colloid photodeposition operated in the presence of a hole scavenger (CPH). The prepared Au nanoparticles supported on TiO₂ showed strong photoabsorption at around 550 nm due to surface plasmon resonance (SPR) of Au and exhibited a photocatalytic activity in mineralization of formic acid in aqueous suspensions under irradiation of visible light (>ca. 520 nm). A linear correlation between photocatalytic activity and the amount of Au loaded, that is, the number of Au nanoparticles, was observed, indicating that the activity of Au/TiO₂ plasmonic photocatalysts can be controlled simply by the amount of Au loading using the CPH method and that the external surface area of Au nanoparticles is a decisive factor in mineralization of formic acid under visible light irradiation. Very high reaction rates were obtained in samples with 5 wt % Au or more, although the rate tended to be saturated. The CPH method can be widely applied for loading of Au nanoparticles on various TiO₂ supports without change in the original size independent of the TiO₂ phase. The rate of CO₂ formation also increased linearly with increase in the external surface area of Au. Interestingly, the TiO₂ supports showed different slopes of the plots. The slope is important for selection of TiO₂ as a material supporting colloidal Au nanoparticles.