Effect of Ag nanoparticle size on the photoelectrochemical properties of Ag decorated TiO₂ nanotube arrays

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• 作者：Kansong Chen ; ^{kschen1999@yahoo.com.cn} ; Xinran Feng ; Rui Hu ; Yuebin Li ; Kun Xie ; Yang Li ; Haoshuang Gu ; ^{guhsh583@yahoo.com.cn}
• 关键词：Silver nanoparticle ; Localized surface plasmon resonance ; Titanium dioxide nanotube arrays ; Photoelectrochemical property
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：25 March, 2013
• 年：2013
• 卷：554
• 期：Complete
• 页码：72-79
• 全文大小：1195 K

文摘

Silver (Ag) nanoparticle decorated titanium dioxide nanotube arrays (TiO₂ NTAs) were fabricated using a two-step method based on an electrochemical anodization procedure followed by a photochemical reduction process. UV-visible diffuse reflectance spectroscopy and photoluminescence emission spectroscopy demonstrated that the Ag decorating significantly enhanced the light absorption of TiO₂ NTAs in the visible spectral range and improved the separation of photo-induced charge carriers in the TiO₂ NTAs. The photoelectrochemical properties of prepared samples were investigated by the transient photocurrent measurement and the potential dependence of photocurrent under visible light irradiation. The results show that the photoelectrochemical behavior of Ag decorated TiO₂ NTAs is dependent on the size of the Ag particles. The maximum photoconversion efficiency of Ag decorated TiO₂ NTAs is about 3.3 times greater than that of bare TiO₂ NTAs. Electrochemical impedance spectroscopy measurements of the subject materials revealed that the photoelectron lifetime of Ag decorated TiO₂ NTAs increases as the Ag nanoparticle¡¯s size decreases. We propose that the enhanced photoelectrochemical properties of Ag decorated TiO₂ NTAs results from different ratios of light absorption to scattering caused by the localized surface plasmon resonance of the various sizes of Ag nanoparticles. The tunable photoelectrochemical properties of Ag decorated TiO₂ NTAs are expected to have promising applications in photoelectrochemical solar cells and other light-harvesting devices.