Sodium iron hexacyanoferrate(FeHCF)is one of the most promising cathode materials for sodium-ion batteries(SIBs)due to its low cost theoretical capacity.However,the low electrochemical activity of Fe^(LS)(C)in FeHCF d...Sodium iron hexacyanoferrate(FeHCF)is one of the most promising cathode materials for sodium-ion batteries(SIBs)due to its low cost theoretical capacity.However,the low electrochemical activity of Fe^(LS)(C)in FeHCF drags down its practical capacity and potential plateau.Herein,FeHCF with high Fe^(LS)(C)electrochemical activity(C-FeHCF)is synthesized via a facile citric acid-assisted solvothermal method.As the cathode of SIBs,C-FeHCF shows superior cycling stability(ca.87.3%capacity retention for 1000 cycles at 10 C)and outstanding rate performance(ca.68.5%capacity retention at 50 C).Importantly,the contribution of Fe^(LS)(C)to the whole capacity was quantitatively analyzed via combining dQ/dV and discharge curve for the first time,and the index reaches 44.53%for C-FeHCF,close to the theoretical value.In-situ X-ray diffraction proves the structure stability of C-FeHCF during charge-discharge process,ensuring its superior cycling performance.Furthermore,the application feasibility of the C-FeHCF cathode in quasi-solid SIBs is also evaluated.The quasi-solid SIBs with the C-FeHCF cathode exhibit excellent electrochemical performance,delivering an initial discharge capacity of 106.5 mAh g^(−1) at 5 C and high capacity retention of 89.8%over 1200 cycles.This work opens new insights into the design and development of advanced cathode materials for SIBs and the beyond.展开更多
Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework...Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework.Herein,post-synthetic and in-situ vacancy repairing strategies are proposed for the synthesis of highquality FeHCF in a highly concentrated Na_(4)Fe(CN)_(6) solution.Both the post-synthetic and in-situ vacancy repaired FeHCF products(FeHCF-P and FeHCF-I)show the significant decrease in the number of vacancy defects and the reinforced structure,which can suppress the side reactions and activate the capacity from low-spin Fe in FeHCF.In particular,FeHCF-P delivers a reversible discharge capacity of 131 mAh g^(−1) at 1 C and remains 109 mAh g^(−1) after 500 cycles,with a capacity retention of 83%.FeHCF-I can deliver a high discharge capacity of 158.5 mAh g^(−1) at 1 C.Even at 10 C,the FeHCF-I electrode still maintains a discharge specific capacity of 103 mAh g^(−1) and retains 75% after 800 cycles.This work provides a new vacancy repairing strategy for the solution synthesis of high-quality FeHCF.展开更多
In-situ microscopic FTIR spectroelectrochemical technique(MFTIRs) was applied to studying the electrochemical oxidation of ascorbic acid(AA) in poly(ethylene glycol)(PEG) paste at a 100 μm diameter Pt disk electrod...In-situ microscopic FTIR spectroelectrochemical technique(MFTIRs) was applied to studying the electrochemical oxidation of ascorbic acid(AA) in poly(ethylene glycol)(PEG) paste at a 100 μm diameter Pt disk electrode. Using this technique, the catalytic ability of cobalt hexacyanoferrate(CoHCF) microcrystalline toward AA oxidation was also studied. It was found that the dispersed CoHCF powder in the PEG paste can generate well shaped thin layer cyclic voltammetric waves with the peak height proportional to the scan rate, corresponding to the Fe centered redox reactions. This oxidation step catalyzed the AA oxidation. Also, this pasted CoHCF powder generated well resolved in situ MFTIRs spectra, by which a chemical interaction between CC bond of AA ring and CoHCF lattice was revealed. A corresponding surface docking mechanism for the catalytic reaction has been proposed.展开更多
We report here the activated carbon and cobalt hexacyanoferrate composite,which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na_(2)SO_(4) aqueous electrolyte.This novel materia...We report here the activated carbon and cobalt hexacyanoferrate composite,which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na_(2)SO_(4) aqueous electrolyte.This novel material combines high specific surface area and electrochemical stability of activated carbon with the redox properties of cobalt hexacyanoferrate,resulting in maximum specific capacitance of 329 F g^(-1) with large voltage working window of 2.0 V.Electrochemical studies indicated that cobalt hexacyanoferrate introduces important pseudocapacitive properties accounting for the overall charge-storage process,especially when I<0.5 A g^(-1).At lower gravimetric currents(e.g.,0.05 A g^(-1))and up to 1.0 V,the presence of cobalt hexacyanoferrate improves the specific energy for more than 300%.In addition,to better understanding the energy storage process we also provided a careful investigation of the electrode materials under dynamic polarization conditions using the in situ Raman spectroscopy and synchrotron light Xray diffraction techniques.Interesting complementary findings were obtained in these studies.We believe that this novel electrode material is promising for applications regarding the energy-storage process in pseudocapacitors with long lifespan properties.展开更多
The exploration of low-strain and high-performance electrode is a crucial issue for aqueous potassiumion battery(AKIB).Herein,a novel potassium mediated iron/manganese binary hexacyanoferrate nanocuboid,i.e.,K_(x)Fe_(...The exploration of low-strain and high-performance electrode is a crucial issue for aqueous potassiumion battery(AKIB).Herein,a novel potassium mediated iron/manganese binary hexacyanoferrate nanocuboid,i.e.,K_(x)Fe_(y)Mn_(1-y)[Fe(CN)_(6)]·nH_(2)O(KFeMnHCF)nanocuboid,with the concentration-gradient(CG)structure is designed as a high-performance cathode for AKIB.Internal the CG-KFeMnHCF nanocuboids,the manganese content gradually decreases from the interior to the surface and the iron content changes reverse,resulting in the concentration-gradient structure.Both experimental and finite element simulation(FEA)results demonstrate the lower internal stress and better mechanical characteristics of CG structured nanocuboid than the homogenous structured one upon ion intercalation/deintercalation processes.Meanwhile,the electrochemical testing and theoretical calculation(DFT)results disclose the substitution of Fe to Mn in the KMnHCF crystal results in the enhanced electronic conductivity,potassium migration and electrochemical kinetics.Taken both advantages from the well-designed architecture and optimized crystal structure,the CG-KFeMnHCF achieves the superior rate capability and ultrahigh stability in aqueous potassium ion system.In particular,the CG-KFe_(0.31)Mn_(0.69)HCF achieves the best comprehensive properties among all the samples.The full AKIBs based on CG-KFe_(0.31)Mn_(0.69)HCF cathode achieves the high energy density(83 Wh kg^(-1)),superior power density,high capacity retention(83%)over high-rate long-term cycles,good adaptation to a wide temperature range(-20 to 40℃)and high reliability even under outside deformations.Therefore,this work not only provides a new clue to design the highperformance cathode,but also promotes the applications of AKIBs for diverse electronics and wide working environments.展开更多
Cobalt hexacyanoferrate (CoHCF) is a potential cathode for aqueous Na-ion batteries due to its high theoretical specific capacity (170 m Ah g^(-1));however,its lower rate capability and cyclability limit its applicati...Cobalt hexacyanoferrate (CoHCF) is a potential cathode for aqueous Na-ion batteries due to its high theoretical specific capacity (170 m Ah g^(-1));however,its lower rate capability and cyclability limit its applications.Structural distortion at a weak N-coordinated crystal field during cycling disintegrates Co,yielding an irreversible reaction.Different Zn amounts ranging 0–1 were added to the Co site to suppress the structural irreversibility of CoHCF,yielding Co_(1-x)Zn_(x)HCF powder;this Zn (x≤0.09) addition reduced the powder’s dimension because the lower four coordination of Zn–N,not the six coordination of Co–N,limits the powder growth.Simultaneously,a small lattice parameter and interaxial angle (~90°) are obtained,implying that a narrower Co_(1-x)Zn_(x)HCF inner structure is formed to accommodate Na ions.Moreover,the electronic conductivity of Co_(1-x)Zn_(x)HCF gradually increased within 0–0.09 range.A smaller particle size with a high surface area leads to a near-surface-limited redox process,similar to a capacitive reaction.Both the surface-limited reaction and electronic conductivity enhances the reversibility due to the smaller charge transfer resistance at the electrode/electrolyte interface caused by Zn addition.Replacing redox-active Co with non-active Zn amount of 0.07 (Co_(1-x)Zn_(x)HCF) slightly reduces the specific capacity from 127 to 119 mAh g^(-1)at 0.1 A g^(-1)due to the shrunken Co charging sites.Rate performance is enhanced by compromising the capacity and reduced distortion,resulting in 81%retention at a 20-times-faster charging rate.Notably,the Co_(1-x)Zn_(x)HCF sample exhibited the good stability while preserving 74%of the initial capacity at 0.5 A g^(-1)after 200 cycles.展开更多
Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the ...Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon(TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.展开更多
Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Ant...Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Antimicrobial potential of these complexes have been evaluated. Antifungal screening of these complexes has been carried out against Mycogone perniciosa and Verticillium fungicola causing wet and dry bubble diseases of button mushroom respectively. Nickel ferrocyanide has been found to be most effective against Mycogone perniciosa with 60% inhibitory effect while cadmium ferrocyanide has exhibited significant potential of 85% against Verticillium fungicola.展开更多
Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of C...Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of CrHCF firm can be understood in term of two structures: Cr1/3Cr(III)Fe(II)(CN), and MCr(III)Fe(II)(CN)(6). Besides,the film exists in amorphous state: the outer layer is porous film, while the inner layer is relatively compact. According to the electrochemical reaction of CrHCF, the lattice can contract and expand with the cations' diffusion.展开更多
In this work,a variety of Cu_(x)Ni_(2-x)Fe(CN)_(6)(x=0,0.4,0.8,1.2,1.6,2)cathodes for ammonium ion batteries are prepared and their electrochemical performances are investigated.During the introduction of copper in ni...In this work,a variety of Cu_(x)Ni_(2-x)Fe(CN)_(6)(x=0,0.4,0.8,1.2,1.6,2)cathodes for ammonium ion batteries are prepared and their electrochemical performances are investigated.During the introduction of copper in nickel hexacyanoferrate,the electrochemical performance varies without changing the structure of nickel hexacyanoferrate.The increase of Cu content in nickel hexacyanoferrate leads to the enhancement of reaction potential and capacity.Electrochemical results suggest that the substitution of Cu for Ni has a positive effect on improving the cycling stability and rate capacity of nickel hexacyanoferrate when x in Cu_(x)Ni_(2-x)Fe(CN)_(6)is less than 0.4.Therefore,Cu_(0.4)Ni_(1.6)Fe(CN)_(6)exhibits the best cycling per-formance(capacity retention of 97.54%at 0.3 C)and the highest rate capacity(41.4 mAh g^(-1)at 10 C)in Cu_(x)Ni_(2-x)Fe(CN)_(6).Additionally,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)tests also reveal that the structural evolution of Cu_(0.4)Ni_(1.6)Fe(CN)_(6)is highly reversible upon NH_(4)^(+)storage.Therefore,this work proposes a candidate material for ammoniumion batteries and offers a novel avenue for adjusting the operating potential of the material.展开更多
Sodium manganese hexacyanoferrate(NaMnHCF)is a promising cathode material for sodiumion batteries(SIBs)due to its low cost and high energy density.The Jahn-Teller effect of Mn,however,leads to the poor structural stab...Sodium manganese hexacyanoferrate(NaMnHCF)is a promising cathode material for sodiumion batteries(SIBs)due to its low cost and high energy density.The Jahn-Teller effect of Mn,however,leads to the poor structural stability of NaMnHCF,resulting in undesired electrochemical performance.Herein,we developed a novel coating strategy and obtained a coreshell structured NaMnHCF through facile Na^(+)-Cs^(+)ion exchange,which naturally produced a robust and insoluble Cs-rich surface layer(CsMnHCF)with several nanometers in thickness on pristine NaMnHCF.It is shown that the Csrich surface plays a positive role in the stability of the NaMnHCF structure by prohibiting the leakage of crystal water,stabilizing the solid-liquid interfaces,and solidifying crystal structure.The electrochemical performance of the core-shell NaMnHCF is dramatically improved with a discharge capacity of 76.3 mAh·g^(-1)after 1000 cycles at 1.0 C and a reversible capacity of 87.0 mAh·g^(-1)at 10.0 C,which is much superior to that of the pristine NaMnHCF with only 26.6 mAh·g^(-1)after 400 cycles and 31 mAh·g^(-1)at 10.0 C.This work reports a new method for the synthesis of core-shell NaMnHCF and provides a novel perspective for the development of advanced NaMnHCF cathode for SIBs.展开更多
Graphite powder-supported cupric hexacyanoferrate (CuHCF) nanoparticles weredispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite,which was used as electrode material to fab...Graphite powder-supported cupric hexacyanoferrate (CuHCF) nanoparticles weredispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite,which was used as electrode material to fabricate surface-renewable CuHCF-modified electrodes.Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterizedusing cyclic and square-wave voltammetry. Cych'c voltammograms at various scan rates indicated thatpeak currents were surface-confined at low scan rates. In the presence of glutathione, a clearelectrocatalytic response was observed at the CuHCF-modified composite electrodes. In addition, theelectrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanicalpolishing on e-mery paper, as well as ease of preparation, and good chemical and mechanicalstability in a flowing stream.展开更多
The widely accepted theory concerning the electrochemical energy storage mechanism of copper hexacyanoferrate(CuHCF)for supercapacitors is that CuHCF stores charge by the reversible redox processes of Fe^3+/Fe2+couple...The widely accepted theory concerning the electrochemical energy storage mechanism of copper hexacyanoferrate(CuHCF)for supercapacitors is that CuHCF stores charge by the reversible redox processes of Fe^3+/Fe2+couple and Cu cations are electrochemically inactive.In this work,CuHCF nanocubes(CuHCF-NC)were synthesized in the presence of potassium citrate and its electrochemical properties were tentatively studied in 1 mol/L Na2 SO4 aqueous electrolyte.Good supercapacitive performance was exhibited.The combined analyses of cyclic voltammogram(CV)and X-ray photoelectron spectroscopy(XPS)disclosed that the CuHCF nanocubes underwent the redox reactions of Fe^3+/Fe2+and Cu^2+/Cu+couples to store charges.The Cu^2+/Cu+redox couple was activated due to the strong coordination interaction between the carboxylate groups of citrate ions and surface Cu cations.展开更多
A thin film of manganese hexacyanoferrate (MnHCF) was electrochemically formed on a glassy carbon (GC) electrode to prepare a chemically modified electrode (CME). The mechanism of film formation of MnHCF and its...A thin film of manganese hexacyanoferrate (MnHCF) was electrochemically formed on a glassy carbon (GC) electrode to prepare a chemically modified electrode (CME). The mechanism of film formation of MnHCF and its growth process were investigated in detail by cyclic voltammetry. The results show that the stoichiometric composition of MnHCF is Mn^ⅢFe^Ⅲ(CN)6, an analogue of prussian yellow. There exist three clear-cut stages in the whole modification process and the last stage is indispensable to the fabrication of homogenized, stable MnHCF film and must last for an appropriate time. The surface morphology of MnHCF/GC electrode was characterized by scanning electron microscopy (SEM), which further verified the effective deposition of MnHCF film on GC. The kinetic constants of MnHCF/GC electrode process were also evaluated. The resulting MnHCF film modified electrode presented good stability and high electrocatalytic activity toward the oxidation of H2O2, indicating that MnHCF film possesses function of catalase and can be expected for analytical purposes.展开更多
An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chlor...An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chloride as a promoter under catalyst-free condition is described.The advantages of this protocol are the use of a nontoxic,nonvolatile and inexpensive cyanating agent,no use of transition metal catalysts,high yield and simple work-up procedure.展开更多
The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercala...The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercalation or formation of alloy/compounds,we aim to introduce and utilize a weak,reversible Fe-N interaction during the(de)intercalation of ammonium ions(NH_(4)^(+))within iron(Ⅲ)hexacyanoferrate(FeHCF),inspired by manipulating the electrostatic adsorption between N and Fe in the early stages of ammonia synthesis(Bosch-Harber Process,Chemical Engineering)and steel nitriding processes(Metal Industry).Such strategy of switching well-balanced Fe-N interaction is confirmed in between the nitrogen of ammonium ions and highspin Fe in FeHCF,as observed by using X-ray absorption spectroscopy.The resulting material provided an extremely stable energy storage(58 mAh g^(-1) after 10000 cycles at current density of 1 A g^(-1))as well as high-rate performance(23.6 mAh g^(-1) at current density of 10 A g^(-1)).展开更多
Aqueous ammonium ion batteries are regarded as eco-friendly and sustainable energy storage systems.And applicable host for NH_(4)^(+)in aqueous solution is always in the process of development.On the basis of density ...Aqueous ammonium ion batteries are regarded as eco-friendly and sustainable energy storage systems.And applicable host for NH_(4)^(+)in aqueous solution is always in the process of development.On the basis of density functional theory calcula-tions,the excellent performance of NH_(4)^(+)insertion in Prussian blue analogues(PBAs)is proposed,especially for copper hexacyanoferrate(CuHCF).In this work,we prove the outstanding cycling and rate performance of CuHCF via electrochemical analyses,delivering no capacity fading during ultra-long cycles of 3000 times and high capacity retention of 93.6%at 50 C.One of main contributions to superior performance from highly reversible redox reaction and structural change is verified during the ammoniation/de-ammoniation progresses.More importantly,we propose the NH_(4)^(+)diffusion mechanism in CuHCF based on con-tinuous formation and fracture of hydrogen bonds from a joint theoretical and experimental study,which is another essential reason for rapid charge transfer and superior NH_(4)^(+)storage.Lastly,a full cell by coupling CuHCF cathode and polyaniline anode is constructed to explore the practical application of CuHCF.In brief,the outstanding aqueous NH_(4)^(+)storage in cubic PBAs creates a blueprint for fast and sustainable energy storage.展开更多
Inexpensive and abundant sodium resources make energy storage systems using sodium chemistry promising replacements for typical lithium-ion rechargeable batteries(LIBs).Fortuitously,aqueous sodium-ion rechargeable bat...Inexpensive and abundant sodium resources make energy storage systems using sodium chemistry promising replacements for typical lithium-ion rechargeable batteries(LIBs).Fortuitously,aqueous sodium-ion rechargeable batteries(ASIBs),which operate in aqueous electrolytes,are cheaper,safer,and more ionically conductive than batteries that operate in conventional organic electrolytes;furthermore,they are suitable for grid-scale energy storage applications.As electrode materials for storing Na~+ ions in ASIBs,a variety of multifunctional metal-organic frameworks(MOFs) have demonstrated great potential in terms of having porous 3 D crystal structures,compatibility with aqueous solutions,long cycle lives(≥1000 cycles),and ease of synthesis.The present review describes MOF-derived technologies for the successful application of MOFs to ASIBs and suggests future challenges in this area of research based on the current understanding.展开更多
Remarkable attention has been directed to Prussian blue(PB) and its analogues(PBA) as one of the most widely used metal-organic frameworks(MOFs) especially in the field of energy storage devices due to their fabulous ...Remarkable attention has been directed to Prussian blue(PB) and its analogues(PBA) as one of the most widely used metal-organic frameworks(MOFs) especially in the field of energy storage devices due to their fabulous features such as 3D open framework, high surface area, controllable distribution of pores and the low cost. Nevertheless, their depressed conductivity causes some insulation when being used as an electrode for supercapacitors leading to be restricted in further applications particularly the electronics. To the best of our knowledge, our review aimed primarily to give a total picture of the research that was done on utilizing PB and PBA for fabricating the electrodes of supercapacitor, studying their synthesis approaches in addition to the hybridization with other materials such as graphene, CNTs and conducting polymer. It also addresses the transformation of PB or PBA into other interesting nanostructures such as oxides, sulfides, and bicomponent of graphitic carbon nitride/metal oxides, as well. Furthermore,It exhibits various avenues for overcoming their disadvantages of bad cycle life, retention rate and not achieving the desired values of energy/power densities opening the door for enlarging the number of researches on their application as supercapacitors.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK20210474)the National Natural Science Foundation of China (No.21938005)the Fundamental Research Funds for the Central Universities (No.JUSRP122013).
文摘Sodium iron hexacyanoferrate(FeHCF)is one of the most promising cathode materials for sodium-ion batteries(SIBs)due to its low cost theoretical capacity.However,the low electrochemical activity of Fe^(LS)(C)in FeHCF drags down its practical capacity and potential plateau.Herein,FeHCF with high Fe^(LS)(C)electrochemical activity(C-FeHCF)is synthesized via a facile citric acid-assisted solvothermal method.As the cathode of SIBs,C-FeHCF shows superior cycling stability(ca.87.3%capacity retention for 1000 cycles at 10 C)and outstanding rate performance(ca.68.5%capacity retention at 50 C).Importantly,the contribution of Fe^(LS)(C)to the whole capacity was quantitatively analyzed via combining dQ/dV and discharge curve for the first time,and the index reaches 44.53%for C-FeHCF,close to the theoretical value.In-situ X-ray diffraction proves the structure stability of C-FeHCF during charge-discharge process,ensuring its superior cycling performance.Furthermore,the application feasibility of the C-FeHCF cathode in quasi-solid SIBs is also evaluated.The quasi-solid SIBs with the C-FeHCF cathode exhibit excellent electrochemical performance,delivering an initial discharge capacity of 106.5 mAh g^(−1) at 5 C and high capacity retention of 89.8%over 1200 cycles.This work opens new insights into the design and development of advanced cathode materials for SIBs and the beyond.
基金supported by the projects of the National Key R&D Program of China(2016YFB0100302)the National Natural Science Foundation of China(Grant No.60306011).
文摘Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework.Herein,post-synthetic and in-situ vacancy repairing strategies are proposed for the synthesis of highquality FeHCF in a highly concentrated Na_(4)Fe(CN)_(6) solution.Both the post-synthetic and in-situ vacancy repaired FeHCF products(FeHCF-P and FeHCF-I)show the significant decrease in the number of vacancy defects and the reinforced structure,which can suppress the side reactions and activate the capacity from low-spin Fe in FeHCF.In particular,FeHCF-P delivers a reversible discharge capacity of 131 mAh g^(−1) at 1 C and remains 109 mAh g^(−1) after 500 cycles,with a capacity retention of 83%.FeHCF-I can deliver a high discharge capacity of 158.5 mAh g^(−1) at 1 C.Even at 10 C,the FeHCF-I electrode still maintains a discharge specific capacity of 103 mAh g^(−1) and retains 75% after 800 cycles.This work provides a new vacancy repairing strategy for the solution synthesis of high-quality FeHCF.
文摘In-situ microscopic FTIR spectroelectrochemical technique(MFTIRs) was applied to studying the electrochemical oxidation of ascorbic acid(AA) in poly(ethylene glycol)(PEG) paste at a 100 μm diameter Pt disk electrode. Using this technique, the catalytic ability of cobalt hexacyanoferrate(CoHCF) microcrystalline toward AA oxidation was also studied. It was found that the dispersed CoHCF powder in the PEG paste can generate well shaped thin layer cyclic voltammetric waves with the peak height proportional to the scan rate, corresponding to the Fe centered redox reactions. This oxidation step catalyzed the AA oxidation. Also, this pasted CoHCF powder generated well resolved in situ MFTIRs spectra, by which a chemical interaction between CC bond of AA ring and CoHCF lattice was revealed. A corresponding surface docking mechanism for the catalytic reaction has been proposed.
基金the financial support from the Brazilian funding agencies CNPq(301486/2016-6)FAPESP(2014/02163-7,2017/11958-1,2018/20756-6)+2 种基金FAPEMIG(Financial support for the LMMA/UFVJM Laboratory)CNPq(PQ-2 grant:Process 301095/2018-3)the support from Shell and the strategic importance of the support given by ANP(Brazil’s National Oil,Natural Gas and Biofuels Agency)through the R&D levy regulation。
文摘We report here the activated carbon and cobalt hexacyanoferrate composite,which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na_(2)SO_(4) aqueous electrolyte.This novel material combines high specific surface area and electrochemical stability of activated carbon with the redox properties of cobalt hexacyanoferrate,resulting in maximum specific capacitance of 329 F g^(-1) with large voltage working window of 2.0 V.Electrochemical studies indicated that cobalt hexacyanoferrate introduces important pseudocapacitive properties accounting for the overall charge-storage process,especially when I<0.5 A g^(-1).At lower gravimetric currents(e.g.,0.05 A g^(-1))and up to 1.0 V,the presence of cobalt hexacyanoferrate improves the specific energy for more than 300%.In addition,to better understanding the energy storage process we also provided a careful investigation of the electrode materials under dynamic polarization conditions using the in situ Raman spectroscopy and synchrotron light Xray diffraction techniques.Interesting complementary findings were obtained in these studies.We believe that this novel electrode material is promising for applications regarding the energy-storage process in pseudocapacitors with long lifespan properties.
基金supported by the Innovation Foundation of Graduate Student of Harbin Normal University(Grant No.HSDSSCX2020-18)the Natural Science Foundation of Heilongjiang Province,China(Grant No.TD2020B001)the Opening Project of State Key Laboratory of Advanced Chemical Power Sources(Grant No.SKL-ACPS-C-25)。
文摘The exploration of low-strain and high-performance electrode is a crucial issue for aqueous potassiumion battery(AKIB).Herein,a novel potassium mediated iron/manganese binary hexacyanoferrate nanocuboid,i.e.,K_(x)Fe_(y)Mn_(1-y)[Fe(CN)_(6)]·nH_(2)O(KFeMnHCF)nanocuboid,with the concentration-gradient(CG)structure is designed as a high-performance cathode for AKIB.Internal the CG-KFeMnHCF nanocuboids,the manganese content gradually decreases from the interior to the surface and the iron content changes reverse,resulting in the concentration-gradient structure.Both experimental and finite element simulation(FEA)results demonstrate the lower internal stress and better mechanical characteristics of CG structured nanocuboid than the homogenous structured one upon ion intercalation/deintercalation processes.Meanwhile,the electrochemical testing and theoretical calculation(DFT)results disclose the substitution of Fe to Mn in the KMnHCF crystal results in the enhanced electronic conductivity,potassium migration and electrochemical kinetics.Taken both advantages from the well-designed architecture and optimized crystal structure,the CG-KFeMnHCF achieves the superior rate capability and ultrahigh stability in aqueous potassium ion system.In particular,the CG-KFe_(0.31)Mn_(0.69)HCF achieves the best comprehensive properties among all the samples.The full AKIBs based on CG-KFe_(0.31)Mn_(0.69)HCF cathode achieves the high energy density(83 Wh kg^(-1)),superior power density,high capacity retention(83%)over high-rate long-term cycles,good adaptation to a wide temperature range(-20 to 40℃)and high reliability even under outside deformations.Therefore,this work not only provides a new clue to design the highperformance cathode,but also promotes the applications of AKIBs for diverse electronics and wide working environments.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science, ICT & Future Planning) (NRF-2020R1F1A1075601, NRF-2021R1A4A2001658)supported by the National Natural Science Foundation of China (51904059)+1 种基金the Fundamental Research Funds for the Central Universities (N182505036, N2002005)the Liao Ning Revitalization Talents Program (XLYC1807123)。
文摘Cobalt hexacyanoferrate (CoHCF) is a potential cathode for aqueous Na-ion batteries due to its high theoretical specific capacity (170 m Ah g^(-1));however,its lower rate capability and cyclability limit its applications.Structural distortion at a weak N-coordinated crystal field during cycling disintegrates Co,yielding an irreversible reaction.Different Zn amounts ranging 0–1 were added to the Co site to suppress the structural irreversibility of CoHCF,yielding Co_(1-x)Zn_(x)HCF powder;this Zn (x≤0.09) addition reduced the powder’s dimension because the lower four coordination of Zn–N,not the six coordination of Co–N,limits the powder growth.Simultaneously,a small lattice parameter and interaxial angle (~90°) are obtained,implying that a narrower Co_(1-x)Zn_(x)HCF inner structure is formed to accommodate Na ions.Moreover,the electronic conductivity of Co_(1-x)Zn_(x)HCF gradually increased within 0–0.09 range.A smaller particle size with a high surface area leads to a near-surface-limited redox process,similar to a capacitive reaction.Both the surface-limited reaction and electronic conductivity enhances the reversibility due to the smaller charge transfer resistance at the electrode/electrolyte interface caused by Zn addition.Replacing redox-active Co with non-active Zn amount of 0.07 (Co_(1-x)Zn_(x)HCF) slightly reduces the specific capacity from 127 to 119 mAh g^(-1)at 0.1 A g^(-1)due to the shrunken Co charging sites.Rate performance is enhanced by compromising the capacity and reduced distortion,resulting in 81%retention at a 20-times-faster charging rate.Notably,the Co_(1-x)Zn_(x)HCF sample exhibited the good stability while preserving 74%of the initial capacity at 0.5 A g^(-1)after 200 cycles.
文摘Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon(TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.
文摘Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Antimicrobial potential of these complexes have been evaluated. Antifungal screening of these complexes has been carried out against Mycogone perniciosa and Verticillium fungicola causing wet and dry bubble diseases of button mushroom respectively. Nickel ferrocyanide has been found to be most effective against Mycogone perniciosa with 60% inhibitory effect while cadmium ferrocyanide has exhibited significant potential of 85% against Verticillium fungicola.
文摘Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of CrHCF firm can be understood in term of two structures: Cr1/3Cr(III)Fe(II)(CN), and MCr(III)Fe(II)(CN)(6). Besides,the film exists in amorphous state: the outer layer is porous film, while the inner layer is relatively compact. According to the electrochemical reaction of CrHCF, the lattice can contract and expand with the cations' diffusion.
基金supported by the Ningbo Natural Science Founda-tion(No.2022J064)the NSAF Joint Fund(No.U1830106)the National Natural Science Foundation of China(No.22209082).
文摘In this work,a variety of Cu_(x)Ni_(2-x)Fe(CN)_(6)(x=0,0.4,0.8,1.2,1.6,2)cathodes for ammonium ion batteries are prepared and their electrochemical performances are investigated.During the introduction of copper in nickel hexacyanoferrate,the electrochemical performance varies without changing the structure of nickel hexacyanoferrate.The increase of Cu content in nickel hexacyanoferrate leads to the enhancement of reaction potential and capacity.Electrochemical results suggest that the substitution of Cu for Ni has a positive effect on improving the cycling stability and rate capacity of nickel hexacyanoferrate when x in Cu_(x)Ni_(2-x)Fe(CN)_(6)is less than 0.4.Therefore,Cu_(0.4)Ni_(1.6)Fe(CN)_(6)exhibits the best cycling per-formance(capacity retention of 97.54%at 0.3 C)and the highest rate capacity(41.4 mAh g^(-1)at 10 C)in Cu_(x)Ni_(2-x)Fe(CN)_(6).Additionally,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)tests also reveal that the structural evolution of Cu_(0.4)Ni_(1.6)Fe(CN)_(6)is highly reversible upon NH_(4)^(+)storage.Therefore,this work proposes a candidate material for ammoniumion batteries and offers a novel avenue for adjusting the operating potential of the material.
基金financially supported by the National Natural Science Foundation of China(Nos.52172184 and 51763022)the Fundamental Research Funds for the Central Universities(No.ZYGX2019J024)。
文摘Sodium manganese hexacyanoferrate(NaMnHCF)is a promising cathode material for sodiumion batteries(SIBs)due to its low cost and high energy density.The Jahn-Teller effect of Mn,however,leads to the poor structural stability of NaMnHCF,resulting in undesired electrochemical performance.Herein,we developed a novel coating strategy and obtained a coreshell structured NaMnHCF through facile Na^(+)-Cs^(+)ion exchange,which naturally produced a robust and insoluble Cs-rich surface layer(CsMnHCF)with several nanometers in thickness on pristine NaMnHCF.It is shown that the Csrich surface plays a positive role in the stability of the NaMnHCF structure by prohibiting the leakage of crystal water,stabilizing the solid-liquid interfaces,and solidifying crystal structure.The electrochemical performance of the core-shell NaMnHCF is dramatically improved with a discharge capacity of 76.3 mAh·g^(-1)after 1000 cycles at 1.0 C and a reversible capacity of 87.0 mAh·g^(-1)at 10.0 C,which is much superior to that of the pristine NaMnHCF with only 26.6 mAh·g^(-1)after 400 cycles and 31 mAh·g^(-1)at 10.0 C.This work reports a new method for the synthesis of core-shell NaMnHCF and provides a novel perspective for the development of advanced NaMnHCF cathode for SIBs.
基金theMinistryofScienceandTechnologyofChina (No .2 0 0 1BA2 10A0 4)
文摘Graphite powder-supported cupric hexacyanoferrate (CuHCF) nanoparticles weredispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite,which was used as electrode material to fabricate surface-renewable CuHCF-modified electrodes.Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterizedusing cyclic and square-wave voltammetry. Cych'c voltammograms at various scan rates indicated thatpeak currents were surface-confined at low scan rates. In the presence of glutathione, a clearelectrocatalytic response was observed at the CuHCF-modified composite electrodes. In addition, theelectrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanicalpolishing on e-mery paper, as well as ease of preparation, and good chemical and mechanicalstability in a flowing stream.
基金supported by the National Natural Science Foundation of China(No.51877029)。
文摘The widely accepted theory concerning the electrochemical energy storage mechanism of copper hexacyanoferrate(CuHCF)for supercapacitors is that CuHCF stores charge by the reversible redox processes of Fe^3+/Fe2+couple and Cu cations are electrochemically inactive.In this work,CuHCF nanocubes(CuHCF-NC)were synthesized in the presence of potassium citrate and its electrochemical properties were tentatively studied in 1 mol/L Na2 SO4 aqueous electrolyte.Good supercapacitive performance was exhibited.The combined analyses of cyclic voltammogram(CV)and X-ray photoelectron spectroscopy(XPS)disclosed that the CuHCF nanocubes underwent the redox reactions of Fe^3+/Fe2+and Cu^2+/Cu+couples to store charges.The Cu^2+/Cu+redox couple was activated due to the strong coordination interaction between the carboxylate groups of citrate ions and surface Cu cations.
基金Project supported by the National Natural Science Foundation of China (No. 20075012) the and the President Science Foundation of South China Agricultural University (No. K05053).
文摘A thin film of manganese hexacyanoferrate (MnHCF) was electrochemically formed on a glassy carbon (GC) electrode to prepare a chemically modified electrode (CME). The mechanism of film formation of MnHCF and its growth process were investigated in detail by cyclic voltammetry. The results show that the stoichiometric composition of MnHCF is Mn^ⅢFe^Ⅲ(CN)6, an analogue of prussian yellow. There exist three clear-cut stages in the whole modification process and the last stage is indispensable to the fabrication of homogenized, stable MnHCF film and must last for an appropriate time. The surface morphology of MnHCF/GC electrode was characterized by scanning electron microscopy (SEM), which further verified the effective deposition of MnHCF film on GC. The kinetic constants of MnHCF/GC electrode process were also evaluated. The resulting MnHCF film modified electrode presented good stability and high electrocatalytic activity toward the oxidation of H2O2, indicating that MnHCF film possesses function of catalase and can be expected for analytical purposes.
基金The authors thank the National Natural Science Foundation of China(Nos.21162024,21362034,21462038)for the financial support of this work.
文摘An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chloride as a promoter under catalyst-free condition is described.The advantages of this protocol are the use of a nontoxic,nonvolatile and inexpensive cyanating agent,no use of transition metal catalysts,high yield and simple work-up procedure.
基金supported by the National Natural Science Foundation of China(51932003,51872115)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)+2 种基金Project for Selfinnovation Capability Construction of Jilin Province Development and Reform Commission(2021C026)the Project supported by State Key Laboratory of Luminescence and Applications(KLA-2020-05)the Fundamental Research Funds for the Central Universities JLU,and“Double-First Class”Discipline for Materials Science&Engineering.
文摘The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercalation or formation of alloy/compounds,we aim to introduce and utilize a weak,reversible Fe-N interaction during the(de)intercalation of ammonium ions(NH_(4)^(+))within iron(Ⅲ)hexacyanoferrate(FeHCF),inspired by manipulating the electrostatic adsorption between N and Fe in the early stages of ammonia synthesis(Bosch-Harber Process,Chemical Engineering)and steel nitriding processes(Metal Industry).Such strategy of switching well-balanced Fe-N interaction is confirmed in between the nitrogen of ammonium ions and highspin Fe in FeHCF,as observed by using X-ray absorption spectroscopy.The resulting material provided an extremely stable energy storage(58 mAh g^(-1) after 10000 cycles at current density of 1 A g^(-1))as well as high-rate performance(23.6 mAh g^(-1) at current density of 10 A g^(-1)).
基金This work is sponsored by NSAF joint Fund(U1830106)Science and Technology Innovation 2025 Major Program of Ningbo(2018B10061)National Natural Science Foundation of China(U1632114,51901205),and K.C.Wong Magna Fund in Ningbo University.
文摘Aqueous ammonium ion batteries are regarded as eco-friendly and sustainable energy storage systems.And applicable host for NH_(4)^(+)in aqueous solution is always in the process of development.On the basis of density functional theory calcula-tions,the excellent performance of NH_(4)^(+)insertion in Prussian blue analogues(PBAs)is proposed,especially for copper hexacyanoferrate(CuHCF).In this work,we prove the outstanding cycling and rate performance of CuHCF via electrochemical analyses,delivering no capacity fading during ultra-long cycles of 3000 times and high capacity retention of 93.6%at 50 C.One of main contributions to superior performance from highly reversible redox reaction and structural change is verified during the ammoniation/de-ammoniation progresses.More importantly,we propose the NH_(4)^(+)diffusion mechanism in CuHCF based on con-tinuous formation and fracture of hydrogen bonds from a joint theoretical and experimental study,which is another essential reason for rapid charge transfer and superior NH_(4)^(+)storage.Lastly,a full cell by coupling CuHCF cathode and polyaniline anode is constructed to explore the practical application of CuHCF.In brief,the outstanding aqueous NH_(4)^(+)storage in cubic PBAs creates a blueprint for fast and sustainable energy storage.
基金supported by a National Research Foundation of Korea, South Korea (NRF) grant funded by the Korean government (MSITMinistry of Science and ICT+1 种基金Information and Communications Technologies) (NRF-2019R1F1A1042080)the Hallym University, South Korea Research Fund, 2019 (HRF-201912-013)。
文摘Inexpensive and abundant sodium resources make energy storage systems using sodium chemistry promising replacements for typical lithium-ion rechargeable batteries(LIBs).Fortuitously,aqueous sodium-ion rechargeable batteries(ASIBs),which operate in aqueous electrolytes,are cheaper,safer,and more ionically conductive than batteries that operate in conventional organic electrolytes;furthermore,they are suitable for grid-scale energy storage applications.As electrode materials for storing Na~+ ions in ASIBs,a variety of multifunctional metal-organic frameworks(MOFs) have demonstrated great potential in terms of having porous 3 D crystal structures,compatibility with aqueous solutions,long cycle lives(≥1000 cycles),and ease of synthesis.The present review describes MOF-derived technologies for the successful application of MOFs to ASIBs and suggests future challenges in this area of research based on the current understanding.
基金the National Research Foundation of Korea Grant funded by the Korean Government(MEST)(NRF2019R1I1A3A01063833)Korea Environment Industry&Technology Institute(KEITI)through Technology Development Program for Environmental Industry Advancement funded by Korea Ministry of Environment(MOE)(RE201805141)+1 种基金the National Research Foundation(NRF)of Korea(NRF-2019R1A2C1006677)Hannam University research fund in 2019。
文摘Remarkable attention has been directed to Prussian blue(PB) and its analogues(PBA) as one of the most widely used metal-organic frameworks(MOFs) especially in the field of energy storage devices due to their fabulous features such as 3D open framework, high surface area, controllable distribution of pores and the low cost. Nevertheless, their depressed conductivity causes some insulation when being used as an electrode for supercapacitors leading to be restricted in further applications particularly the electronics. To the best of our knowledge, our review aimed primarily to give a total picture of the research that was done on utilizing PB and PBA for fabricating the electrodes of supercapacitor, studying their synthesis approaches in addition to the hybridization with other materials such as graphene, CNTs and conducting polymer. It also addresses the transformation of PB or PBA into other interesting nanostructures such as oxides, sulfides, and bicomponent of graphitic carbon nitride/metal oxides, as well. Furthermore,It exhibits various avenues for overcoming their disadvantages of bad cycle life, retention rate and not achieving the desired values of energy/power densities opening the door for enlarging the number of researches on their application as supercapacitors.