Highly Active Supported Plasmonic Photocatalyst Consisting of Gold Nanoparticle-Loaded Mesoporous Titanium(IV) Oxide Overlayer and Conducting Substrate

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• 作者：Kume Takahiro ; Shin-ichi Naya ; Hiroaki Tada
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：November 20, 2014
• 年：2014
• 卷：118
• 期：46
• 页码：26887-26893
• 全文大小：359K
• ISSN：1932-7455

文摘

We prepared mesoporous films consisting of gold nanoparticle-loaded titanium dioxide nanoparticles on various conducting substrates including FTO, ITO, Ti, Au, and Pt (Au/mp-TiO₂/conducting substrate), and a glass plate for comparison. Electrochemical characterization of Au/mp-TiO₂/FTO substrate clarified that the mesoporous structure of the Au/TiO₂ overlayer permits the permeation of solution into the mesopores to reach the FTO surface. The visible-light activity (位 > 430 nm) of the immobilized 鈥減lasmonic photocatalysts鈥?was evaluated for the oxidations of benzylamine and cinnamyl alcohol. The visible-light activity strongly depended on the kind of the substrates. Visible-light irradiation of Au/mp-TiO₂/FTO in an aqueous solution of benzylamine selectively produced benzaldehyde with 鈭?00% yield at 16 h, while the yields for the Au/mp-TiO₂/glass and Au/TiO₂ particle systems were 鈭?5% under the same conditions. In the selective oxidation of cinnamyl alcohol to cinnamaldehyde, the Au/mp-TiO₂/conducting substrate photocatalysts using Ti, Au, and Pt as the substrate showed significantly higher activities than even Au/TiO₂ particles. By the technique for labeling and visualizing the reduction sites (J. Phys. Chem. B 2000, 104, 4585), this remarkable substrate effect was shown to originate from the long-range charge separation by the successive interfacial electron transfer from Au nanoparticle to the substrate through TiO₂. A good positive correlation was found between the visible-light activity of Au/mp-TiO₂/conducting substrate and the electrocatalytic activity of the conducting substrate for O₂ reduction.