A Novel Method for Preparing V-doped Titanium Dioxide Thin Film Photocatalysts with High Photocatalytic Activity Under V
- PDF / 390,304 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 88 Downloads / 139 Views
A Novel Method for Preparing V-doped Titanium Dioxide Thin Film Photocatalysts with High Photocatalytic Activity Under Visible Light Irradiation De-En Gu Æ Bang-Chao Yang Æ Yong-Da Hu
Received: 17 April 2007 / Accepted: 18 June 2007 / Published online: 17 July 2007 Springer Science+Business Media, LLC 2007
Abstract The liquid phase deposition (LPD) method was successfully used for preparing V-doped TiO2 thin film photocatalysts. In this simple and easily-controlled process, V-doped anatase TiO2 thin films were directly deposited on a soda lime glass substrate placed in an aqueous solution containing Ti- and V-fluoro complex ions, followed by annealing. The thin films were analyzed by XRD, XPS, UV-vis. V4+ ions were introduced into the lattice of TiO2 through in-situ substituting Ti4+. The absorption edge of V-doped TiO2 films shifted to visible light region. The highly efficient photocatalytic activity was verified by the decomposition of methylene blue under visible light irradiation. Keywords Titanium dioxide thin films Liquid phase deposition Vanadium Visible light photocatalytic activity Methylene blue
1 Introduction A titanium dioxide (TiO2) photocatalyst has gained more and more importance in the past decades due to its excellent capability of degrading a large variety of environmental contaminants such as organics, bacteria, viruses [1, 2], especially following the discovery of the photoinduced water-splitting on TiO2 [3]. However, the widespread application of TiO2 as a photocatalyst has been cumbered with its wide band gap (3.2 eV for anatase
D.-E. Gu (&) B.-C. Yang Y.-D. Hu School of Microeletronics and Solid-state Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China e-mail: [email protected]
123
TiO2). This requires ultraviolet (UV) irradiation for photocatalytic activity. UV light accounts for a small fraction (~5%) of the sun rays on the surface of the earth comparing with visible light. So, shifting the absorption edge of a TiO2 photocatalyst from UV to the visible spectral range can provide the groundwork to the development of TiO2 catalysts with visible light (vis-) photocatalytic activity. Several attempts have been made to develop vis-photocatalytic TiO2 catalysts [1, 4–7]. Doping of TiO2 with transition metal ions is one of the important approaches [7– 9]. Of the transition metals for doping (V, Cr, Mo, Fe, etc.), V has been one of the frequent topics of investigation because of conspicuous absorption in the visible region [10– 14]. The methods for preparing V-doped TiO2 catalysts are: a sol–gel method, a metal ion-implantation method, a coprecipitation method, and other methods [10–16]. Among these methods, a coprecipitation method and a sol– gel method are widely employed due to being low-cost and easy to execute. A coprecipitation method is often used for preparing V-doped TiO2 powders [15, 16]. A sol–gel method is frequently used for depositing the V-doped TiO2 films [11–13]. However, easily-hydrolyzed organic materials, such as titanium
Data Loading...
