Effect of surface state properties of modified TiO_2 powders on their photocatalytic activity

GIEC OpenIR

	Effect of surface state properties of modified TiO_2 powders on their photocatalytic activity
	Li Fangbai 1; Hou Meifang 1; Li Xinjun2 ; Li Xiangzhong 3; Wang Liangyan 2
	2002
发表期刊	Transactions of Nonferrous Metals Society of China
ISSN	1003-6326
卷号	12 期号:4 页码:707
摘要	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 TiO_2, an innovative photo-catalyst 3%WO_3/0.5%Au~(3+)/TiO_2 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 photo-voltage 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 TiO_2. And the surface state of O_2~- forms. For(1%, 3%)Au~(3+)/TiO_2 sample, two new peaks that significantly present at 414nm and 400nm respectively should be attributable to gold impurity energy level. And for tungsten oxides doping samples, 4 peaks that significantly present in the region of 500～800nm 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.
语种	英语
文献类型	期刊论文
条目标识符	http://ir.giec.ac.cn/handle/344007/20698
专题	中国科学院广州能源研究所
作者单位	1.Guangdong Institute of Eco-Environment and Soil Science 2.中国科学院广州能源研究所 3.香港理工大学
推荐引用方式 GB/T 7714	Li Fangbai,Hou Meifang,Li Xinjun,et al. Effect of surface state properties of modified TiO_2 powders on their photocatalytic activity[J]. Transactions of Nonferrous Metals Society of China,2002,12(4):707.
APA	Li Fangbai,Hou Meifang,Li Xinjun,Li Xiangzhong,&Wang Liangyan.(2002).Effect of surface state properties of modified TiO_2 powders on their photocatalytic activity.Transactions of Nonferrous Metals Society of China,12(4),707.
MLA	Li Fangbai,et al."Effect of surface state properties of modified TiO_2 powders on their photocatalytic activity".Transactions of Nonferrous Metals Society of China 12.4(2002):707.