物理化学学报 >> 2013, Vol. 29 >> Issue (08): 1705-1711.doi: 10.3866/PKU.WHXB201306043

电化学和新能源 上一篇    下一篇

CMPO-离子液体萃取分离铀(VI)体系的电化学性质

吴京珂, 沈兴海, 陈庆德   

  1. 北京大学化学与分子工程学院, 放射化学与辐射化学重点学科实验室, 北京分子科学国家实验室, 北京 100871
  • 收稿日期:2013-03-29 修回日期:2013-06-03 发布日期:2013-07-09
  • 通讯作者: 沈兴海 E-mail:xshen@pku.edu.cn
  • 基金资助:

    国家自然科学基金(91226112, 20871009)资助项目

Electrochemical Behavior of the System of Uranium(VI) Extraction with CMPO-Ionic Liquid

WU Jing-Ke, SHEN Xing-Hai, CHEN Qing-De   

  1. Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2013-03-29 Revised:2013-06-03 Published:2013-07-09
  • Contact: SHEN Xing-Hai E-mail:xshen@pku.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (91226112, 20871009).

摘要:

研究了辛基(苯基)-N,N-二异丁基胺甲酰基甲基氧化膦(CMPO)-离子液体(IL)从硝酸铀酰水溶液中萃取铀(VI)的电化学行为, 离子液体(IL)为1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺盐(C4mimNTf2). 用等摩尔系列法测得萃取过程中CMPO与U(VI)形成摩尔比为3:1的配合物. 用循环伏安法研究了萃取液中U(VI)-CMPO配合物的电化学性质, 结果表明, 在C4mimNTf2中U(VI)-CMPO 配合物经过准可逆还原生成U(V)-CMPO 配合物, U(VI)/U(V)电对的表观氧化还原电势(EΘ, vs Fc/Fc+)为(?0.885±0.008) V. 对萃取液进行控制电位电解, 发现在铂片上有沉淀析出. X射线光电子能谱(XPS) 测试结果表明, 沉积物中只含有U(VI)、U(IV)和氧, 而CMPO和C4mimNTf2没有被夹带析出.

关键词: 铀, 离子液体, 萃取, 循环伏安, 电沉积

Abstract:

The electrochemical behavior of U(VI) extracted from an aqueous solution of uranyl nitrate by octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in an ionic liquid was investigated. The hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C4mimNTf2) was used in this study. Using an equimolar series method, we found that CMPO and U(VI) formed a 3:1 molar complex during the extraction process. Cyclic voltammetry was used to investigate the electrochemical behavior of the U(VI)-CMPO complex in C4mimNTf2. The U(VI)-CMPO complex was found to be quasi-reversibly reduced to a U(V)-CMPO complex. The formal redox potential (EΘ, vs Fc/Fc+) for the U(VI)/U(V) couple was determined to be (-0.885±0.008) V. Controlled-potential electrolysis of the extract gave a deposit on the surface of a platinum plate. X-ray photoelectron spectroscopy showed that the deposit contained only U(VI), U(IV), and oxygen, and the CMPO extractant and the ionic liquid were not trapped in the deposit.

Key words: ?Uranium, Ionicliquid, Extraction, Cyclicvoltammetry, Electrodeposition

MSC2000: 

  • O646