电化学控制离子分离（electrochemically controlled ion separation，ECIS）是一种环境友好的新型膜分离技术，通过电化学方法调节附着在导电基体上的离子交换膜的氧化还原电位来控制离子的置入与释放，从而使溶液中的金属离子得到分...电化学控制离子分离（electrochemically controlled ion separation，ECIS）是一种环境友好的新型膜分离技术，通过电化学方法调节附着在导电基体上的离子交换膜的氧化还原电位来控制离子的置入与释放，从而使溶液中的金属离子得到分离并使膜得到再生。铁氰化镍（NiHCF）是一种结构类似分子筛的无机配位化合物，由于其对碱金属离子的选择性（Cs^＋〉Rb^＋〉K^＋〉Na^＋〉Li^＋）不同可用于分离混合溶液中的碱金属离子，成为电控离子分离膜的首选材料。就ECIS过程机理、NiHCF薄膜的制备-结构-性能关系进行了总结并提出了一些新的研究方向。展开更多
The ion selectivity of electrodeposited nickel hexacyanoferrate （NiHCF） thin films was investigated using electrochemical impedance spectroscopy （EIS） and cyclic voltammetry （CV）. NiHCF thin films were prepared ...The ion selectivity of electrodeposited nickel hexacyanoferrate （NiHCF） thin films was investigated using electrochemical impedance spectroscopy （EIS） and cyclic voltammetry （CV）. NiHCF thin films were prepared by cathodic deposition on Pt and Al substrates. EIS and CV curves were determined in 1 mol/L （KNO3＋C5NO3） and 1 mol/L （NaNO3＋CsNO3） mixture solutions, which were sensitive to the concentration of Cs^＋ in the electrolytes. Experimental results show that all Nyquist impedance plots show depressed semicircles in the high-frequency range changing over into straight lines at lower frequencies. With increasing amounts of Cs^＋, the redox potentials in CV curves shift toward more positive values and the redox peaks broaden; the semicircle radius in corresponding EIS curves and the charge transfer resistance also increase. EIS combining CV is able to provide valuable insights into the ion selectivity of NiHCF thin films. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
A nickel hexacyanoferrate(NiHCF)film electrode was prepared with NiHCF,conductive carbon black,and polyvinylidene difluoride,which was coated on graphite plate substrate for selective extraction of Cs^(+)ions by using...A nickel hexacyanoferrate(NiHCF)film electrode was prepared with NiHCF,conductive carbon black,and polyvinylidene difluoride,which was coated on graphite plate substrate for selective extraction of Cs^(+)ions by using electrochemically switched ion exchange(ESIX)technology.A potential-responsive ionpump system for efficient extraction of Cs+ions was designed,and the effect of wet film thicknesses,charging modes,flow rates,and chamber widths on Cs+ions extraction performance was investigated.In the system,the adsorption capacity and removal percentage of Cs^(+)ions on the NiHCF film electrode reached as high as 147.69 mg·g^(-1)and 92.47%,respectively.Furthermore,the NiHCF film electrode showed high selectivity for Cs^(+)ions and stability.After seven cycles of adsorption/desorption,the desorption percentage could reach about 100%.The excellent Cs^(+)extraction performance should be attributed to the strong driving force produced by the potential-responsive ion-pumping effect in the ESIX process,as well as the low ion transfer resistance of the film electrode which is caused by the special crystal structure of NiHCF.In addition,the NiHCF film electrode was implemented to work together with the bismuth oxybromide(BiOBr)film electrode to accomplish the simultaneous extraction of Cs^(+)and Br^(-).And the adsorption capacity and removal percentage of Br^(-)ions on the BiOBr film electrode reached 69.53 mg·g^(-1)and 77.32%,correspondingly.It is expected that such a potential-responsive ion-pump system based on NiHCF and BiOBr film electrodes could be used for the selective extraction and concentration of Cs^(+)and Br^(-)ions from salt lake brine.展开更多
文摘在碳纤维/石墨基体上通过毛细化学沉积法制备出具有高离子交换容量与高稳定性的铁氰化镍(nickel hexacyanoferrate,NiHCF)薄膜电极。采用循环伏安法考察了在石墨颗粒粒径100μm、PTFE含量0.05g/g石墨、乙醇量4ml/g石墨、制膜液浓度0.1mol/L(含1.07mol/L乙醇)条件下得到碳纤维/石墨基膜电极的离子交换容量、循环寿命与再生能力;并通过SEM、XPS分析了膜电极表面形貌、组成。研究结果表明,此多孔石墨基体电极比表面积大,沉积得到的NiHCF膜具有较大的离子分离能力、良好的循环稳定性与再生能力,可用于电化学控制离子分离(electro-chemically controlled ion separation,ECIS)过程。
基金国家自然科学基金资助项目（20676089）山西省自然科学基金资助项目（2007011029）+1 种基金省回国留学人员基金资助项目（2004-24）省青年学术带头人基金资助项目（2005）.Acknowledgement： The authors thank Prof D. T. Schwartz and Dr. W. A. Stecn（University of Washington） for discussions and constructive suggestions.
文摘电化学控制离子分离（electrochemically controlled ion separation，ECIS）是一种环境友好的新型膜分离技术，通过电化学方法调节附着在导电基体上的离子交换膜的氧化还原电位来控制离子的置入与释放，从而使溶液中的金属离子得到分离并使膜得到再生。铁氰化镍（NiHCF）是一种结构类似分子筛的无机配位化合物，由于其对碱金属离子的选择性（Cs^＋〉Rb^＋〉K^＋〉Na^＋〉Li^＋）不同可用于分离混合溶液中的碱金属离子，成为电控离子分离膜的首选材料。就ECIS过程机理、NiHCF薄膜的制备-结构-性能关系进行了总结并提出了一些新的研究方向。
基金the National Natural Science Foundation of China(No.20676089)the Scholar Council Foundation of Shanxi Province,China(No.2004-24).
文摘The ion selectivity of electrodeposited nickel hexacyanoferrate （NiHCF） thin films was investigated using electrochemical impedance spectroscopy （EIS） and cyclic voltammetry （CV）. NiHCF thin films were prepared by cathodic deposition on Pt and Al substrates. EIS and CV curves were determined in 1 mol/L （KNO3＋C5NO3） and 1 mol/L （NaNO3＋CsNO3） mixture solutions, which were sensitive to the concentration of Cs^＋ in the electrolytes. Experimental results show that all Nyquist impedance plots show depressed semicircles in the high-frequency range changing over into straight lines at lower frequencies. With increasing amounts of Cs^＋, the redox potentials in CV curves shift toward more positive values and the redox peaks broaden; the semicircle radius in corresponding EIS curves and the charge transfer resistance also increase. EIS combining CV is able to provide valuable insights into the ion selectivity of NiHCF thin films. 2008 University of Science and Technology Beijing. All rights reserved.
基金supported by the National Natural Science Foundation of China(22108188,U21A20303,U20A20141)CAS Project for Young Scientists in Basic Research(YSBR-039)。
文摘A nickel hexacyanoferrate(NiHCF)film electrode was prepared with NiHCF,conductive carbon black,and polyvinylidene difluoride,which was coated on graphite plate substrate for selective extraction of Cs^(+)ions by using electrochemically switched ion exchange(ESIX)technology.A potential-responsive ionpump system for efficient extraction of Cs+ions was designed,and the effect of wet film thicknesses,charging modes,flow rates,and chamber widths on Cs+ions extraction performance was investigated.In the system,the adsorption capacity and removal percentage of Cs^(+)ions on the NiHCF film electrode reached as high as 147.69 mg·g^(-1)and 92.47%,respectively.Furthermore,the NiHCF film electrode showed high selectivity for Cs^(+)ions and stability.After seven cycles of adsorption/desorption,the desorption percentage could reach about 100%.The excellent Cs^(+)extraction performance should be attributed to the strong driving force produced by the potential-responsive ion-pumping effect in the ESIX process,as well as the low ion transfer resistance of the film electrode which is caused by the special crystal structure of NiHCF.In addition,the NiHCF film electrode was implemented to work together with the bismuth oxybromide(BiOBr)film electrode to accomplish the simultaneous extraction of Cs^(+)and Br^(-).And the adsorption capacity and removal percentage of Br^(-)ions on the BiOBr film electrode reached 69.53 mg·g^(-1)and 77.32%,correspondingly.It is expected that such a potential-responsive ion-pump system based on NiHCF and BiOBr film electrodes could be used for the selective extraction and concentration of Cs^(+)and Br^(-)ions from salt lake brine.
