XAFS study of Cu^(2+) in aqueous solution of CuBr_2  

作　　者：DAI Binbin WANG Qian MA Jingyuan LI Jiong ZHANG Shuo HUANG Yuying HUANG Wei WU Guozhong ZOU Yang JIANG Zheng XU Hongjie 

机构地区：[1]Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China

出　　处：《Nuclear Science and Techniques》2012年第3期129-133,共5页核技术（英文）

基　　金：Supported by National Natural Science Foundation of China (Grant No.11005148,10705046,11135008);National Basic Research Program of China (Grant No. 2010CB934501);Special Presidential Foundation of the Chinese Academy of Science (Grant No. 29);Science and Technology Commission of Shanghai Municipality (Grant No. 11JC1414900)

摘　　要：Copper ion is the essential microelement to many organisms. In this paper, the local structure of Cu2+ in CuBr2 aqueous solutions with different concentrations are investigated by using X-ray absorption fine structure (XAFS) technique. XANES (X-ray Absorption Near Edge Structure) spectra indicate that charge transfer from Br- to Cu2+ decreases with the solution concentration, which lead to a shift of the absorption edge. The shoulder appearing at the rising edge proves to be characteristic of a tetragonal distortion. The Fourier transform magnitudes of EXAFS (Extended X-ray absorption fine structure) data of Cu species suggest that more Cu-Br bonds may exist in high concentrations. A fivefold coordination configuration like a pyramid is used as the fitting parameters. From the analysis of the coordination numbers, the proportion of Cu-O and Cu-Br is 4:1 in the saturated solution. The Br atom is on the equatorial plane of the model. The fitting results agree well with the experiment data.Copper ion is the essential microelement to many organisms. In this paper, the local structure of Cu2＋ in CuBr2 aqueous solutions with different concentrations are investigated by using X-ray absorption fine structure （XAFS） technique. XANES （X-ray Absorption Near Edge Structure） spectra indicate that charge transfer from Br- to Cu2＋ decreases with the solution concentration, which lead to a shift of the absorption edge. The shoulder appearing at the rising edge proves to be characteristic of a tetragonal distortion. The Fourier transform magnitudes of EXAFS （Extended X-ray absorption fine structure） data of Cu species suggest that more Cu-Br bond,; may exist in high concentrations. A fivefold coordination configuration like a pyramid is used as the fitting parameters. From the analysis of the coordination numbers, the proportion of Cu-O and Cu-Br is 4：1 in the saturated selution. The Br atom is on the equatorial plane of the model. The fitting results agree well with the experiment data.

关 键 词：EXAFS 水溶液 X-射线吸收精细结构 X射线吸收精细结构 X射线吸收近边结构 XANES 傅立叶变换 微量元素 

分 类 号：O643.36[理学—物理化学] O647.2[理学—化学]