Thin films of capillary deposited nickel hexacyanoferrate(NiHCF) were investigated as electrochemically switched ion exchange(ESIX) materials. The films were generated on platinum and graphite substrates based on the ...Thin films of capillary deposited nickel hexacyanoferrate(NiHCF) were investigated as electrochemically switched ion exchange(ESIX) materials. The films were generated on platinum and graphite substrates based on the ternary reagent diagram. In 1 mol/L KNO3 solution, cyclic voltammetry(CV) combined with energy-dispersive X-ray spectroscopy(EDS) was used to determine the influence of experimental conditions on the electroactivity of the NiHCF thin film on Pt substrates. The ion selectivity, ion-exchange capacity and the regenerability of NiHCF films on Pt and graphite substrates were investigated. The experiment results show that the NiHCF thin films from Ni2+-poor growth conditions have double peaks CV curves and contain relatively larger amount of potassium; while those from Ni2+-rich growth conditions are single peak CV curves and contain relatively smaller amount of potassium. It is demonstrated that the NiHCF thin films of capillary chemical deposition have good ESIX performances.展开更多
The ion selectivity of nickel hexacyanoferrate thin film to alkali cations in ESIX (electrochemically switched ion exchange) processes was investigated using molecular dynamics(MD) techniques; water and cation (Na+ an...The ion selectivity of nickel hexacyanoferrate thin film to alkali cations in ESIX (electrochemically switched ion exchange) processes was investigated using molecular dynamics(MD) techniques; water and cation (Na+ and Cs+) intercalation, configuration, and dynamics in reduced nickel hexacyanoferrate structures with different cation combinations were studied and compared with the experimental results. In the simulations, water was represented by an extended simple point-charge(SPC/E) model, and all other atomic interactions were represented by a universal force field(UFF). The potential energies of various cations combination (Cs+ and Na+) in reduced i-NiHCF and 1 mol/L Cs/NaCl mixed solution were obtained. In most cases, the total potential energy of the solid is reduced when water is intercalated into the various reduced NiHCF structures. Combining the solid and the solution simulation results, it is shown that the solid composition of 3Cs+/1Na+ is the stablest structure form (NaCs3Ni4[Fe(CN)6]3) over a range of solution compositions.展开更多
电化学控制离子交换(electrochemically switched ion exchange,ESIX)是电化学与离子交换相结合的新型离子分离技术,通过电化学方法调节导电基体上电活性ESIX膜的氧化/还原状态来控制离子的置入与释放,从而使溶液中的离子得到分离,并使...电化学控制离子交换(electrochemically switched ion exchange,ESIX)是电化学与离子交换相结合的新型离子分离技术,通过电化学方法调节导电基体上电活性ESIX膜的氧化/还原状态来控制离子的置入与释放,从而使溶液中的离子得到分离,并使膜得到再生。ESIX消除了传统离子交换技术在化学再生过程中产生的二次污染问题,因其环境友好性在废水处理及水质净化领域具有良好的应用前景而逐渐成为备受关注的热点问题。本文简述了ESIX技术的机理和特点,着重阐述了有关ESIX膜的制备、结构及其应用方面的研究进展,并指出了需要研究的科学问题与研究前景。展开更多
电控离子交换(Electrochemically switched ion exchange,ESIX)系统内对电极具有保持溶液电中性、增强提锂效果且使系统形成闭合回路的关键作用。在ESIX技术盐湖提锂过程中人们主要关注锂离子捕获电极,关于对电极的研究较少。而本文研...电控离子交换(Electrochemically switched ion exchange,ESIX)系统内对电极具有保持溶液电中性、增强提锂效果且使系统形成闭合回路的关键作用。在ESIX技术盐湖提锂过程中人们主要关注锂离子捕获电极,关于对电极的研究较少。而本文研究了不同类型对电极对ESIX系统提锂性能的影响。分别采用聚吡咯/导电炭黑/聚偏二氟乙烯(PPy/C/PVDF)、活性炭/导电炭黑/聚偏二氟乙烯(AC/C/PVDF)和石墨板电极作为ESIX系统中锰酸锂/导电炭黑/聚偏二氟乙烯(LiMn_(2)O_(4)/C/PVDF)提锂膜电极的对电极,考察了这3种ESIX系统在氯化物型高镁锂比模拟卤水(Mg/Li~50)中的提锂性能。结果表明,当PPy/C/PVDF作为对电极时可有效吸附卤水中Cl^(-),且ESIX系统提锂性能最优,Li^(+)吸附量为13.9 mg/g;当PPy/C/PVDF电极湿膜厚度增加至1 mm时,ESIX系统对Li^(+)的提取率可达44.2%,Li^(+)/Mg^(2+)分离因子可达56.82。因此,针对不同的阴离子型盐湖卤水设计匹配的对电极对ESIX技术在盐湖提锂领域的发展具有重要的理论指导意义。展开更多
研究了利用电控离子交换技术对工业废水中的Cl-进行去除。考察了Cl-含量、电极电流密度以及共存阴离子等对聚吡咯(PPy)纳米复合电活性离子交换膜电极的除氯性能的影响。结果表明,初始Cl-含量对其脱除速率影响较小;电流密度在0.99 m A/c...研究了利用电控离子交换技术对工业废水中的Cl-进行去除。考察了Cl-含量、电极电流密度以及共存阴离子等对聚吡咯(PPy)纳米复合电活性离子交换膜电极的除氯性能的影响。结果表明,初始Cl-含量对其脱除速率影响较小;电流密度在0.99 m A/cm^2时PPy膜对Cl-脱除效果为好;膜电极连续20次脱氯、再生循环证明Cl-置入量较为稳定,基本保持在90%以上,脱附效率在75%以上。在体积流量4 m L/min、电流密度0.99 m A/cm2时动态脱除Cl-时,Cl-置入膜内较为完全,且PPy电极材料可以多次重复使用具有较好的稳定性。展开更多
基金Project(20006011) supported by the National Natural Science Foundation of China Project(20021017) supported by the Natural Science Foundation of Shanxi Province Project(2004-24) supported by the Scholar Council Foundation of Shanxi Province, China
文摘Thin films of capillary deposited nickel hexacyanoferrate(NiHCF) were investigated as electrochemically switched ion exchange(ESIX) materials. The films were generated on platinum and graphite substrates based on the ternary reagent diagram. In 1 mol/L KNO3 solution, cyclic voltammetry(CV) combined with energy-dispersive X-ray spectroscopy(EDS) was used to determine the influence of experimental conditions on the electroactivity of the NiHCF thin film on Pt substrates. The ion selectivity, ion-exchange capacity and the regenerability of NiHCF films on Pt and graphite substrates were investigated. The experiment results show that the NiHCF thin films from Ni2+-poor growth conditions have double peaks CV curves and contain relatively larger amount of potassium; while those from Ni2+-rich growth conditions are single peak CV curves and contain relatively smaller amount of potassium. It is demonstrated that the NiHCF thin films of capillary chemical deposition have good ESIX performances.
基金Project (20006011) supported by the National Natural Science Foundation of China Project (20021017) by the Natural Science Foundation of Shanxi Province Project (2004-24) by the Scholarship Council Foundation of Shanxi Province
文摘The ion selectivity of nickel hexacyanoferrate thin film to alkali cations in ESIX (electrochemically switched ion exchange) processes was investigated using molecular dynamics(MD) techniques; water and cation (Na+ and Cs+) intercalation, configuration, and dynamics in reduced nickel hexacyanoferrate structures with different cation combinations were studied and compared with the experimental results. In the simulations, water was represented by an extended simple point-charge(SPC/E) model, and all other atomic interactions were represented by a universal force field(UFF). The potential energies of various cations combination (Cs+ and Na+) in reduced i-NiHCF and 1 mol/L Cs/NaCl mixed solution were obtained. In most cases, the total potential energy of the solid is reduced when water is intercalated into the various reduced NiHCF structures. Combining the solid and the solution simulation results, it is shown that the solid composition of 3Cs+/1Na+ is the stablest structure form (NaCs3Ni4[Fe(CN)6]3) over a range of solution compositions.
文摘电化学控制离子交换(electrochemically switched ion exchange,ESIX)是电化学与离子交换相结合的新型离子分离技术,通过电化学方法调节导电基体上电活性ESIX膜的氧化/还原状态来控制离子的置入与释放,从而使溶液中的离子得到分离,并使膜得到再生。ESIX消除了传统离子交换技术在化学再生过程中产生的二次污染问题,因其环境友好性在废水处理及水质净化领域具有良好的应用前景而逐渐成为备受关注的热点问题。本文简述了ESIX技术的机理和特点,着重阐述了有关ESIX膜的制备、结构及其应用方面的研究进展,并指出了需要研究的科学问题与研究前景。
文摘研究了利用电控离子交换技术对工业废水中的Cl-进行去除。考察了Cl-含量、电极电流密度以及共存阴离子等对聚吡咯(PPy)纳米复合电活性离子交换膜电极的除氯性能的影响。结果表明,初始Cl-含量对其脱除速率影响较小;电流密度在0.99 m A/cm^2时PPy膜对Cl-脱除效果为好;膜电极连续20次脱氯、再生循环证明Cl-置入量较为稳定,基本保持在90%以上,脱附效率在75%以上。在体积流量4 m L/min、电流密度0.99 m A/cm2时动态脱除Cl-时,Cl-置入膜内较为完全,且PPy电极材料可以多次重复使用具有较好的稳定性。
