EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn( II ) onto TiO2

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境水质学国家重点实验室

	EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn( II ) onto TiO2
	Gao Shuang ; Chen Hao ; He Guang-Zhi ; Pan Gang
刊名	CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
	2009-12-10
卷号	30 期号:12 页码:2439-2444
关键词	Extended X-ray absorption fine structure pH Adsorption reversibility Zn( II )
中文摘要	Microscopic structures and thermodynamic characteristics of Zn( II ) adsorbed onto anatase TiO2 at different pH were studied using extended X-ray absorption fine structure(EXAFS) spectroscopy. Macroscopic adsorption-desorption experiments indicated that as pH increased from 5.8 to 6.8, the adsorption capacity coefficient( K-F ) increased from 1.345 L/g to 15.385 L/g, while the adsorption irreversibility coefficient ( T II ) decreased from 0.43 to 0.23. EXAFS spectra results showed that Zn( II ) was adsorbed onto the solid surface in a mixed form of octahedral and tetrahedral hydrous Zn( II ) ions, which were linked to TiO2 surface by sharing 0 atoms. Both the bond length and the coordination number of the first Zn-O coordination sphere decreased as pH increased. Analysis of the second Zn-Ti coordination sphere indicated two Zn-Ti atomic distances: R-1 = 0.319-0.334 nm and R-2 = 0.366-0.378 nm, referring to bidentate ( stronger adsorption site) and monodentate (weaker adsorption site) complexation respectively. The number of stronger adsorption sites ( CN1) decreased while the number of weaker adsorption sites ( CN2) increased remarkably with increasing pH, resulting In a drop of CN1/CN2 from 2.12 to 0.89. EXAFS results revealed that the macroscopic adsorption phenomena were directly related to the changes in microscopic adsorption structures of Zn( H) on the surface of TiO2 under different pH conditions.
WOS记录号	WOS:000273792900023
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/21677]
专题	生态环境研究中心_环境水质学国家重点实验室
推荐引用方式 GB/T 7714	Gao Shuang,Chen Hao,He Guang-Zhi,et al. EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn( II ) onto TiO2[J]. CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE,2009,30(12):2439-2444.
APA	Gao Shuang,Chen Hao,He Guang-Zhi,&Pan Gang.(2009).EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn( II ) onto TiO2.CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE,30(12),2439-2444.
MLA	Gao Shuang,et al."EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn( II ) onto TiO2".CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE 30.12(2009):2439-2444.