,XAFS study of Cu2+ in aqueous solution of CuBr2

• 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: Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201204,China
• 出 处: 核技术（英文版）
• 发表日期: 2012年3期
• 关键词: CuBr2 Aqueous solution XAFS coordination

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.