Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/22869
Title: Effect of surface state properties of modified TiO2 powders on their photo-catalytic activity
Authors: Li, FB
Li, XJ
Li, XZ
Hou, MF
Wang, LY
Keywords: Surface state
Titanium dioxide
Tungsten oxide
Surface photovoltage spectra
Methylene blue
Gold ion
Issue Date: 2002
Publisher: Nonferrous Metals Society of China, Zhongguo Youse Jinshu Xuehui
Source: Transactions of Nonferrous Metals Society of China (中国有色金属学会会刊) (英文版), 2002, v. 12, no. 4, p. 707-711 How to cite?
Journal: Transactions of Nonferrous Metals Society of China (中国有色金属学会会刊) (英文版) 
Abstract: With an attempt to investigate the effect of gold impurity and tungsten oxide on the recombination and separation of electron-hole pairs, and disclose the effect of surface state on the photo-catalytic activity of TiO2, an innovative photo-catalyst 3% WO3/0.5%Au3+/TiO2 was prepared by means of sol-gel method. The photo-oxidation efficiency of photo-catalyst was evaluated by conducting a set of experiments to photo-degrade methylene blue (MB) in aqueous solution. The surface state properties were examined by means of surface photovoltage spectra (SPS) and electron-field-induced SPS (EFISPS). The experiments demonstrate that the strongest peak is attributed to electron excited from valence band to conduction band and the second strongest peak is attributed to electron excited from valence band to oxygen molecular for all samples. Electron is trapped by O-2 absorbed on the surface of TiO2. And,the surface state of O-2(-) forms. For (1%, 3%)Au3+/TiO2 sample, two new peaks that significantly present at 414 nm and 400 nm respectively should be attributable to gold impurity energy level. And for tungsten oxides doping samples, 4 peaks that significantly present in the region of 500similar to800 nm should be attributable to tungsten impurity energy level. The intensity of EFISPS decreases with increasing the content of gold ion or tungsten oxide when its content is no more than their optimal dosage. However, when the content of gold ion or tungsten oxide is more than their optimal dosage, impurity energy level becomes recombination center from separation center and the intensity of all peaks increases for them.
Description: 4th International Workshop on Ordered Intermetallic Compounds and Advanced Materials, Zhangjiajie, Peoples R China, 8-12 October 2001
URI: http://hdl.handle.net/10397/22869
ISSN: 1003-6326
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