Mechanism of Arsenate (V) Adsorption on TiO2 Surfaces

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	Mechanism of Arsenate (V) Adsorption on TiO2 Surfaces
	Zhang Mei-Yi ; He Guang-Zhi ; Ding Cheng-Cheng ; Chen Hao ; Pan Gang
刊名	ACTA PHYSICO-CHIMICA SINICA
	2009-10
卷号	25 期号:10 页码:2034-2038
关键词	TiO2 As(V) Adsorption Extended X-ray absorption fine structure Density functional theory Microscopic adsorption mode
中文摘要	Adsorption of arsenate on TiO, surfaces was investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DIFT) calculation. The adsorption process was independent of ion strength, indicating the formation of inner-sphere complexes of arsenate on TiO, surfaces. EXAFS analysis showed that the -AsO4 tetrahedral geometry remained relatively rigid before and after adsorption with an As-O distance (R) of (0.1.69+/-0.001) nm. When -AsO4 approached TiO2 surfaces, the As-O-Ti bond formed through the O atoms in -AsO4 clusters. Furthermore, based on the combined results from EXAFS and DFT, As(V) in the 1, equilibrium" adsorption samples was in at least two metastable equilibrium adsorption (MEA) states: double comer (DQ linkage mode (R-1=(0.321+/-0.002) nm, stronger adsorption) and single comer (SC) linkage mode (R-2=(0.360+/-0.002) nm, weak adsorption). The proportion of coordination number between DC and SC MEA states (CNI/CN,) decreased from 3.3 to 1.6 as the surface coverage increased from 9.79 to 28.0 mg . g(-1). This result indicated that at low Surface loading arsenate was adsorbed in more stable DC MEA state, but As(V) tended to be adsorbed in SC MEA state as surface coverage increased.
WOS记录号	WOS:000271079900014
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/21698]
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	Zhang Mei-Yi,He Guang-Zhi,Ding Cheng-Cheng,et al. Mechanism of Arsenate (V) Adsorption on TiO2 Surfaces[J]. ACTA PHYSICO-CHIMICA SINICA,2009,25(10):2034-2038.
APA	Zhang Mei-Yi,He Guang-Zhi,Ding Cheng-Cheng,Chen Hao,&Pan Gang.(2009).Mechanism of Arsenate (V) Adsorption on TiO2 Surfaces.ACTA PHYSICO-CHIMICA SINICA,25(10),2034-2038.
MLA	Zhang Mei-Yi,et al."Mechanism of Arsenate (V) Adsorption on TiO2 Surfaces".ACTA PHYSICO-CHIMICA SINICA 25.10(2009):2034-2038.