Abstract
Ag-TiO2 nanostructured thin films with silver volume fraction of 0–20% were deposited on silicon and quartz substrates by RF magnetron sputtering and annealed in ambient air at 950°C for 1 h. The phase structure and surface topography of the films were characterized by X-ray diffractometer and transmission electron microscope. Photocatalytic activity of the films was evaluated by light induced degradation of methyl orange (C14H14N3NaO3S) solution using a high pressure mercury lamp as lamp-house. The relation of photocatalytic activity and silver content was studied in detail. It was found that silver content influences phase structure of TiO2 thin films, and silver in the films is metallic Ag (Ag0). With increasing silver content from 0 to 20 vol%, photocatalytic activity of the films increases first and then decreases. A suitable amount (2.5–5 vol%) silver addition can significantly enhance the photocatalytic activity of TiO2 films. The enhanced photocatalytic activity was mainly attributed to the extension of visible light absorption region of the films, the presence of anatase phase, the increase of oxygen anion radicals O −2 and reactive center of surface Ti3+, and the better separation between electrons and holes on the films surface.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Fujishima A, Honda K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238(1): 37–38
Yu Y, Yu J C, Chan C Y, et al. Enhancement of adsorption and photocatalytic activity of TiO2 by using carbon nanotubes for the treatment of azo dye. Appl Catal B: Environ, 2005, 61(1–2): 1–11
Young C, Lim T M, Chiang K, et al. Photocatalytic oxidation of toluene and trichloroethylene in the gas-phase by metallised (Pt, Ag) titanium dioxide. Appl Catal B: Environ, 2008, 78(1–2): 1–10
Paramasivam I, Macak J M, Schmuki P. Photocatalytic activity of TiO2 nanotube layers loaded with Ag and Au nanoparticles. Electrochem Commun, 2008, 10(1): 71–75
Kontapakdee K, Panpranot J, Praserthdam P. Effect of Ag addition on the properties of Pd-Ag/TiO2 catalysts containing different TiO2 crystalline phases. Catal Commun, 2007, 8(12): 2166–2170
Wang P, Huang B B, Qin X Y, et al. Ag@AgCl: A highly efficient and stable photocatalyst active under visible light. Angew Chem Int Ed, 2008, 47(41): 7931–7933
He X, Zhao X J, Liu B S. The synthesis and kinetic growth of anisotropic silver particles loaded on TiO2 surface by photoelectrochemical reduction method. Appl Surf Sci, 2008, 254(6): 1705–1709
Xiao L, Cao C B, Song X P, et al. Microstructure and optical properties of nano Ag-ITO films. Sci China Tech Sci, 2010, 53(5): 1266–1270
Meng F M, Song X P, Sun Z Q. Photocatalytic activity of TiO2 thin films deposited by RF magnetron sputtering. Vacuum, 2009, 83(9): 1147–1151
Choi W, Fermin A, Hoffmann M R. The role of metal ion dopants in quantum-sized TiO2: correlation between photoreactivity and charge carrier recombination dynamics. J Phys Chem, 1994, 98(51): 13669–13679
Fujishima A, Rao T N, Tryk D A. Titanium dioxide photocatalysis. J Photochem Photobiol C: Photochem Rev, 2000, 1(1): 1–21
Liu S X, Qu Z P, Han X W, et al. A mechanism for enhanced photocatalytic activity of silver-loaded titanium dioxide. Catal Today, 2004, 93–95: 877–884
Xu M W, Bao S J, Zhang X G. Enhanced photocatalytic activity of magnetic TiO2 photocatalyst by silver deposition. Mater Lett, 2005, 59(17): 2194–2198
He C, Yu Y, Hu X F, et al. Influence of silver doping on the photocatalytic activity of titania films. Appl Surf Sci, 2002, 200(1–4): 239–247
Meng F M, Lu F. Effect of silver content on energy gap and phase structure of silver-titania thin films prepared by radio frequency magnetron sputtering. J Chinese Ceram Soc, 2009, 37(12): 2130–2134
Linsebigler A L, Lu G Q, Yates J T. Photocatalysis on TiO2 surfaces: principles, mechanisms, and selected results. Chem Rev, 1995, 95(3): 735–758
Sato S, White J M. Photodecomposition of water over Pt/TiO2 catalysts. Chem Phys Lett, 1980, 72(1): 83–86
Jafiezic-Renault N, Pichat P, Foissy A, et al. Study of the effect of deposited platinum particles on the surface charge of titania aqueous suspensions by potentiometry, electrophoresis, and labeled-ion adsorption. J Phys Chem, 1986, 90(12): 2733–2738
Nakato Y, Tsubomura H. Structures and functions of thin metal layers on semiconductor electrodes. J Photochem, 1985, 29(1–2): 257–266
Ueda K, Nakato Y, Suzuki N, et al. Silicon electrodes coated with extremely small platinum islands for efficient solar energy conversion. J Electrochem Soc, 1989, 136(8): 2280–2285
Kobayashi H, Mizuno F, Nakato Y, et al. Hydrogen evolution at a platinum-modified indium phosphide photoelectrode: improvement of current-voltage characteristics by hydrogen chloride etching. J Phys Chem, 1991, 95(2): 819–824
Liu S X, Liu H. Photocatalysis and Photoelectrical Catalysis’ Basic and Application (in Chinese). 1st ed. Beijing: Chemical Industry Press, 2006
Hoffmann M R, Martin S T, Choi W Y, et al. Environmental applications of semiconductor photocatalysis. Chem Rev, 1995, 95(1): 69–96
Herrmann J M. Heterogeneous photocatalysis: fundamentals and applications to the removal of various types of aqueous pollutants. Catal Today, 1999, 53(1): 115–129
Sadeghi M, Liu W, Zhang T G, et al. Role of photoinduced charge carrier separation distance in heterogeneous photocatalysis: oxidative degradation of CHOH vapor in contact with Pt/TiO and cofumed TiO-FeO. J Phys Chem, 1996, 100(50): 19466–19474
Gerisher H, Heller A. The role of oxygen in photooxidation of organic molecules on semiconductor particles. J Phys Chem, 1991, 95(13): 5261–5267
Mardare D, Luca D, Teodorescu C M, et al. On the hydrophilicity of nitrogen-doped TiO2 thin films. Surf Sci, 2007, 601(18): 4515–4520
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Meng, F., Lu, F., Sun, Z. et al. A mechanism for enhanced photocatalytic activity of nano-size silver particle modified titanium dioxide thin films. Sci. China Technol. Sci. 53, 3027–3032 (2010). https://doi.org/10.1007/s11431-010-4116-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-010-4116-z