Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been...Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been developed to maximize the performance of CO_(2) electrolyzers,despite its role as the core in regulating ion transport and preventing product crossover or fuel loss.Herein,we report the synthesis of alkaline anion-exchange membranes fabricated by poly(vinyl-alcohol)(PVA)and poly[(3-methyl-1-vinylimidazoliummethylsulfate)-co-(1-vinylpyrrolidone)](PQ44)for use in CO_(2) electrolysis.Owing to the unique imidazolium ring structure coupled with a three-dimensional semiinterpenetrating porous internal architecture,the PVA/PQ44-OH-membranes provide a high hydroxide conductivity(21.47 mS cm^(-1)),preferable mechanical property and thermal stability.In particular,the eCO_(2)RR used PVA/PQ44-OH^(-) as electrolyte membrane realized a charming Faradaic efficiency(88%)and partial current density(29 mA cm^(-2))at0.96 VRHE and,delivered the excellent durability over 20 h electrolysis in 0.5 mol L^(-1) KHCO_(3) electrolyte.Notably,it can even enable an ultrahigh current density beyond 100 mA cm^(-2) at^(-1).11 VRHE when the electrolyte was KOH instead,and produced the FEHCOOof 85%at a low potential of0.81 VRHE,superior to both commercial alkaline A201 and acidic Nafion117 membrane.展开更多
Metallothionein (MT) has a great capacity of binding heavy metals showing an interesting connection with metal toxicology, as a biochemical marker for environmental metal pollution. Anino-exchange high per formance li...Metallothionein (MT) has a great capacity of binding heavy metals showing an interesting connection with metal toxicology, as a biochemical marker for environmental metal pollution. Anino-exchange high per formance liquid chromatography (HPLC) was used to isolate and quantitate MT in livers of minks which were contaminated with heavy metals. MT isoforms (MT-I and MT-II) were eluted at approximately 11.3 and 14.3 min respectively from a DEAE-5 PW anion-exchange column with a Tris-HCl buffer (0.01 -0.25 mol/L, pH 8.6) and detected by UV absorbance at 254 nm. The cadmium concentrations in mink liver MT elutkms were determined by graphite furnace atomic absorption spectrometry (GFAAS) . Obvious increase in liver MT-I concentration rather than liver MT-II was found when the minks were contaminated by feeding contaminated fish captured from the heavy metal-polluted river. The cadmium concentration in mink liver MT-I also increased to some extent as the contaminated level increased.展开更多
Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of ado...Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of adopting platinum-group-metal-free catalysts,anion-exchange membrane fuel cell has received notable attention.However,the sluggish kinetics of anodic hydrogen oxidation reaction(HOR)largely limit the cell efficiency.Although many high-performance HOR catalysts have been reported,there are analytical uncertainties in the literature concerning the assessment of the catalyst activity.Here we determine the origin of false HOR currents in the recorded polarization curves and propose a rigorous approach to eliminate them.We unveil experimentally the uncertainties of obtaining exchange current densities(j0)using Tafel plot from Bulter–Volmer equation and recommend employing the micro-polarization region method.For bulky catalysts that cannot establish a well-defined diffusion layer,we suggest applying external stirring bar to offer certain level of enforced convection and using j0 to compare the activity.展开更多
Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismu...Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.展开更多
During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger...During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy 3+ > Ho 3+ > Gd 3+ >Eu 3+ >Er 3+ >Y 3+ >Sm 3+ >Tm 3+ >Nd 3+ >Pr 3+ >>La 3+ . In the affinity series La 3+ is characterised as the lowest affinity in comparison with other rare earth elements, which indicates possibility of purification of La 3+ from all remaining lanthanides as well as Pr 3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA 1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La 3+ from Pr 3+ complexes with iminodiacetic acid.展开更多
The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate- fructose is described. The adsorption of the system on anion exchange resin is reported.
Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclus...Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclusion/penetration effect for cations and the anion-exchange effect for anions to anion-exchange resin phase.This system is useful for simultaneous separation and determination of ammonium ion(NH+4),nitrite ion(NO-2),and nitrate ion(NO-3) in water samples.The resolution of analyte ions can be manipulated by changing the concentration of base in eluent on a polystyrene-divinylbenzene based strongly basic anion-exchange resin column.In this study,several separation columns,which consisted of different particle sizes,different functional groups and different anion-exchange capacities,were compared.As the results,the separation column with the smaller anion-exchange capacity(TSKgel Super IC-Anion) showed well-resolved separation of cations and anions.In the optimization of the basic eluent,lithium hydroxide(LiOH) was used as the eluent and the optimal concentration was concluded to be 2 mmol/L,considering the resolution of analyte ions and the whole retention times.In the optimal conditions,the relative standard deviations of the peak areas and the retention times of NH+4,NO-2,and NO-3 ranged 1.28%-3.57% and 0.54%-1.55%,respectively.The limits of detection at signal-to-noise of 3 were 4.10 μmol/L for NH+4,1.87 μmol/L for NO-2 and 2.83 μmol/L for NO-3.展开更多
The aim of this paper is the assessment of Donnan dialysis coupled to adsorption process for the removal of chromium from aqueous solutions. This study was conducted in order to benefit from each process, and it was a...The aim of this paper is the assessment of Donnan dialysis coupled to adsorption process for the removal of chromium from aqueous solutions. This study was conducted in order to benefit from each process, and it was an original and new combination. The coupling was a solution to improve the contact time and the amount of chromium (VI) removed. The coupling was successfully performed with 90% of chromium (VI) removed after 6 hours.展开更多
The removal of chromium (VI) from aqueous solutions by Donnan dialysis has been investigated in this paper. In this process, two anion-exchange membranes (AEMs) were used: Selemion? AMV and Neosepta? AFN. The amount o...The removal of chromium (VI) from aqueous solutions by Donnan dialysis has been investigated in this paper. In this process, two anion-exchange membranes (AEMs) were used: Selemion? AMV and Neosepta? AFN. The amount of chromium (VI) removed was determined in terms of the following parameters: initial concentration of chromium (VI), type of anion-exchange membrane, concentration of counter-ion and magnetic stirring rate. A 24 full factorial design analysis was performed to screen the parameters affecting the Cr (VI) removal efficiency. Using the experimental results, a linear mathematical model representing the influence of the different parameters as well as their interactions was obtained. Analysis of the variance (ANOVA), the F-test and the student’s test shows that the type of anion-exchange membrane is the most significant parameter affecting the chromium (VI) removal. The statistical analysis of the experimental data assumes it to be a normal distribution.展开更多
Owing to their unique design and development,high safety and low-cost efficient cathode is still at the forefront of research for rechargeable zinc-ion batteries.However,the suitable cathode operating with ultrahigh c...Owing to their unique design and development,high safety and low-cost efficient cathode is still at the forefront of research for rechargeable zinc-ion batteries.However,the suitable cathode operating with ultrahigh capacity with a dendrite-free anode reaction mechanism remains challenging.In this,the first archetype of a high-rate and morphologically stabled cathode material is constructed from novel cauliflower-like nano-ZnV_(2)S_(4)for aqueous zinc-ion batteries.Thus,nano-ZnV_(2)S_(4)was prepared with an anion exchange reaction using ZnV2(OH)8 cauliflower-like nanostructured array as a template interestingly no morphological and shape changes were detected.The as-prepared nano-ZnV_(2)S_(4)electrode reveals a specific discharge capacity of 348.2 mAh/g during 0.5 A/g with enhanced rate capability and excellent capacity retention of 89.2%at 4 A/g current density even after completing 1000 cycles.展开更多
基金support from the“Scientific and Technical Innovation Action Plan”Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)the National Natural Science Foundation of China (21972017).
文摘Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been developed to maximize the performance of CO_(2) electrolyzers,despite its role as the core in regulating ion transport and preventing product crossover or fuel loss.Herein,we report the synthesis of alkaline anion-exchange membranes fabricated by poly(vinyl-alcohol)(PVA)and poly[(3-methyl-1-vinylimidazoliummethylsulfate)-co-(1-vinylpyrrolidone)](PQ44)for use in CO_(2) electrolysis.Owing to the unique imidazolium ring structure coupled with a three-dimensional semiinterpenetrating porous internal architecture,the PVA/PQ44-OH-membranes provide a high hydroxide conductivity(21.47 mS cm^(-1)),preferable mechanical property and thermal stability.In particular,the eCO_(2)RR used PVA/PQ44-OH^(-) as electrolyte membrane realized a charming Faradaic efficiency(88%)and partial current density(29 mA cm^(-2))at0.96 VRHE and,delivered the excellent durability over 20 h electrolysis in 0.5 mol L^(-1) KHCO_(3) electrolyte.Notably,it can even enable an ultrahigh current density beyond 100 mA cm^(-2) at^(-1).11 VRHE when the electrolyte was KOH instead,and produced the FEHCOOof 85%at a low potential of0.81 VRHE,superior to both commercial alkaline A201 and acidic Nafion117 membrane.
文摘Metallothionein (MT) has a great capacity of binding heavy metals showing an interesting connection with metal toxicology, as a biochemical marker for environmental metal pollution. Anino-exchange high per formance liquid chromatography (HPLC) was used to isolate and quantitate MT in livers of minks which were contaminated with heavy metals. MT isoforms (MT-I and MT-II) were eluted at approximately 11.3 and 14.3 min respectively from a DEAE-5 PW anion-exchange column with a Tris-HCl buffer (0.01 -0.25 mol/L, pH 8.6) and detected by UV absorbance at 254 nm. The cadmium concentrations in mink liver MT elutkms were determined by graphite furnace atomic absorption spectrometry (GFAAS) . Obvious increase in liver MT-I concentration rather than liver MT-II was found when the minks were contaminated by feeding contaminated fish captured from the heavy metal-polluted river. The cadmium concentration in mink liver MT-I also increased to some extent as the contaminated level increased.
基金supported by the National Basic Research Program of China(No.2018YFA0702001)the National Natural Science Foundation of China(Nos.22225901,21975237,and 22175162)+3 种基金the Anhui Provincial Research and Development Program(No.202004a05020073)the Fundamental Research Funds for the Central Universities(No.WK2340000101)the USTC Research Funds of the Double First-Class Initiative(No.YD2340002007)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(No.RERU2022007).
文摘Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of adopting platinum-group-metal-free catalysts,anion-exchange membrane fuel cell has received notable attention.However,the sluggish kinetics of anodic hydrogen oxidation reaction(HOR)largely limit the cell efficiency.Although many high-performance HOR catalysts have been reported,there are analytical uncertainties in the literature concerning the assessment of the catalyst activity.Here we determine the origin of false HOR currents in the recorded polarization curves and propose a rigorous approach to eliminate them.We unveil experimentally the uncertainties of obtaining exchange current densities(j0)using Tafel plot from Bulter–Volmer equation and recommend employing the micro-polarization region method.For bulky catalysts that cannot establish a well-defined diffusion layer,we suggest applying external stirring bar to offer certain level of enforced convection and using j0 to compare the activity.
基金financially supported by Australian Research Council Discovery Project(DP200100965)。
文摘Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.
文摘During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy 3+ > Ho 3+ > Gd 3+ >Eu 3+ >Er 3+ >Y 3+ >Sm 3+ >Tm 3+ >Nd 3+ >Pr 3+ >>La 3+ . In the affinity series La 3+ is characterised as the lowest affinity in comparison with other rare earth elements, which indicates possibility of purification of La 3+ from all remaining lanthanides as well as Pr 3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA 1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La 3+ from Pr 3+ complexes with iminodiacetic acid.
文摘The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate- fructose is described. The adsorption of the system on anion exchange resin is reported.
基金supported by Grant-in-Aid for Scientific Research(23615003)in Japan Society for the Promotion of Science(JSPS)
文摘Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclusion/penetration effect for cations and the anion-exchange effect for anions to anion-exchange resin phase.This system is useful for simultaneous separation and determination of ammonium ion(NH+4),nitrite ion(NO-2),and nitrate ion(NO-3) in water samples.The resolution of analyte ions can be manipulated by changing the concentration of base in eluent on a polystyrene-divinylbenzene based strongly basic anion-exchange resin column.In this study,several separation columns,which consisted of different particle sizes,different functional groups and different anion-exchange capacities,were compared.As the results,the separation column with the smaller anion-exchange capacity(TSKgel Super IC-Anion) showed well-resolved separation of cations and anions.In the optimization of the basic eluent,lithium hydroxide(LiOH) was used as the eluent and the optimal concentration was concluded to be 2 mmol/L,considering the resolution of analyte ions and the whole retention times.In the optimal conditions,the relative standard deviations of the peak areas and the retention times of NH+4,NO-2,and NO-3 ranged 1.28%-3.57% and 0.54%-1.55%,respectively.The limits of detection at signal-to-noise of 3 were 4.10 μmol/L for NH+4,1.87 μmol/L for NO-2 and 2.83 μmol/L for NO-3.
文摘The aim of this paper is the assessment of Donnan dialysis coupled to adsorption process for the removal of chromium from aqueous solutions. This study was conducted in order to benefit from each process, and it was an original and new combination. The coupling was a solution to improve the contact time and the amount of chromium (VI) removed. The coupling was successfully performed with 90% of chromium (VI) removed after 6 hours.
文摘The removal of chromium (VI) from aqueous solutions by Donnan dialysis has been investigated in this paper. In this process, two anion-exchange membranes (AEMs) were used: Selemion? AMV and Neosepta? AFN. The amount of chromium (VI) removed was determined in terms of the following parameters: initial concentration of chromium (VI), type of anion-exchange membrane, concentration of counter-ion and magnetic stirring rate. A 24 full factorial design analysis was performed to screen the parameters affecting the Cr (VI) removal efficiency. Using the experimental results, a linear mathematical model representing the influence of the different parameters as well as their interactions was obtained. Analysis of the variance (ANOVA), the F-test and the student’s test shows that the type of anion-exchange membrane is the most significant parameter affecting the chromium (VI) removal. The statistical analysis of the experimental data assumes it to be a normal distribution.
基金The authors acknowledge the funding for this project through the National Nature Science Foundations of China(No.51873083)Jasmine Jiangsu Fellowship of Jiangsu Province(No.180511800007)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX20_1453).
文摘Owing to their unique design and development,high safety and low-cost efficient cathode is still at the forefront of research for rechargeable zinc-ion batteries.However,the suitable cathode operating with ultrahigh capacity with a dendrite-free anode reaction mechanism remains challenging.In this,the first archetype of a high-rate and morphologically stabled cathode material is constructed from novel cauliflower-like nano-ZnV_(2)S_(4)for aqueous zinc-ion batteries.Thus,nano-ZnV_(2)S_(4)was prepared with an anion exchange reaction using ZnV2(OH)8 cauliflower-like nanostructured array as a template interestingly no morphological and shape changes were detected.The as-prepared nano-ZnV_(2)S_(4)electrode reveals a specific discharge capacity of 348.2 mAh/g during 0.5 A/g with enhanced rate capability and excellent capacity retention of 89.2%at 4 A/g current density even after completing 1000 cycles.
