Potassium Nickel Hexacyanoferrate Research Articles

Potassium-Hydrogen Hybrid Ion Alkaline Battery: A New Rechargeable Aqueous Battery Combined a K+ Storage Cathode and an Electrochemical Hydrogen Storage Anode.

A rechargeable aqueous hybrid ion alkaline battery, using a proton and a potassium ion as charge carriers for the anode and cathode, respectively, is proposed in this study by using well-developed potassium nickel hexacyanoferrate as the cathode material and mesoporous carbon sheets as the anode material, respectively. The constructed battery operates in a concentrated KOH solution, in which the energy storage mechanism for potassium nickel hexacyanoferrate involves the redox reaction of Fe2+/Fe3+ associated with potassium ion insertion/extraction and the redox reaction of Ni(OH)2/NiOOH. The mechanism for the carbon anode is electrochemical hydrogen storage. The cathode made of potassium nickel hexacyanoferrate exhibits both an ultrahigh capacity of 232.7 mAh g-1 under 100 mA g-1 and a consistent performance of 214 mAh g-1 at 2000 mA g-1 (with a capacity retention of 92.8% after 200 cycles). The mesoporous carbon sheet anode exhibits a capacity of 87.6 mAh·g-1 at 100 mA g-1 with a good rate and cyclic performance. The full cell provides an operational voltage of 1.55 V, a capacity of 93.6 mAh g-1 at 100 mA g-1, and 82.4% capacity retention after 1000 cycles at 2000 mA g-1 along with a low self-discharge rate. The investigation and discussion about the energy storage mechanisms for both electrode materials are also provided.

Ammonia Recovery from Manure Wastewater and Simultaneous Electrosynthesis and Wastewater Treatment Using Ion Selective Redox Material

The environmental pressure due to greenhouse gas emissions and water contamination generated by livestock manure motivates the development of new approaches to reduce their environmental impacts and improve sustainability. Effective approaches to recover nutrients, especially ammonia, from manure wastewater to produce fertilizer are needed. Here we develop a new electrochemical strategy to achieve simultaneous ammonium (NH4 +) ion recovery and electrochemical synthesis using potassium nickel hexacyanoferrate as the ammonium ion-selective redox material to mediate the process. Our approach is built on our recent advances in designing modular electrochemical synthesis mediated using redox active materials (which we call redox reservoirs). Specifically, NH4 + (and K+) can be spontaneously uptaken from manure wastewater with a nutrient (NH4 + and K+) selectivity of ~100% driven by the oxidation of organic matter. Subsequently, NH4 +-rich fertilizers are released electrochemically together with the electrosynthesis of value-added chemicals, such as H2O2 as a disinfectant, without expensive ion-exchange membranes. We will also discuss our preliminary results on simultaneous advanced oxidation processes to improve the treatment of PFAS chemicals in wastewater. These results provide a new conceptual strategy for distributed electrochemical resource recovery and on-demand electrochemical manufacturing that can improve the sustainability of agricultural and wastewater treatment processes

Potassium nickel hexacyanoferrate–polyacrylonitrile composite for removing cobalt, strontium, and cesium from radioactive laundry wastewater

AbstractThe applicability of potassium nickel hexacyanoferrate–polyacrylonitrile (KNiFC–PAN) for the sorption of Co2+, Sr2+, and Cs+ from radioactive laundry wastewater generated in nuclear power plants was investigated. Competitive sorption of Co2+, Sr2+, and Cs+ onto KNiFC–PAN was studied for single, binary, and ternary solutions. The Langmuir, Freundlich, Kargi–Ozmıhci, Koble–Corrigan, and Langmuir–Freundlich models predicted the single‐sorption data (R2 ≥ 0.942, sum of squared error ≤ 0.105). The sorption isotherms were nonlinearly favorable (Freundlich coefficient, NF = 0.288–0.842). According to the Langmuir, Freundlich, Kargi–Ozmıhci, Koble–Corrigan, and Langmuir–Freundlich models, at pH 5 (C0 = 20 mM), KNiFC−PAN exhibited the highest maximum sorption capacity (qmL) for Cs+ among the investigated cations, wherein the primary mechanism was physical sorption. The competition between the metal ions in the binary and ternary systems reduced the respective sorption capacities. Binary and ternary sorption models, such as the ideal adsorbed solution theory (IAST) model coupled with Freundlich (IAST–Freundlich), IAST–Langmuir, and IAST–Langmuir–Freundlich models, were fitted to the experimental data; among these, the IAST–Freundlich model was the most accurate for the binary and ternary systems. The presence of sodium 4‐n‐octylbenzenesulfonate and dodecylbenzene–sulfonic acid sodium salt as anionic surfactants strongly affected the sorption capacity on KNiFC–PAN owing to increased distribution coefficients (Kd) of Cs+, Sr2+, and Co2+. Thus, KNiFC–PAN is promising for removing Cs+, Sr2+, and Co2+ from radioactive laundry wastewater.

Ammonium Recovery from Manure Wastewater and Simultaneous Electrosynthesis Using Ammonium-Ion Selective Redox Material

The environmental pressure due to greenhouse gas emissions and water contamination generated by livestock manure motivates the development of new approaches to reduce their environmental impacts and improve sustainability. Effective approaches to recover nutrients, especially ammonium, from manure wastewater to produce fertilizer are needed. Here we develop a new electrochemical strategy to achieve simultaneous ammonium recovery and electrochemical synthesis using potassium nickel hexacyanoferrate (KNiHCF) as the ammonium ion-selective redox material to mediate the processes. The KNiHCF electrode spontaneously uptakes ammonium (and K+) from manure wastewater with a nutrient (NH4 + and K+) selectivity of ~100% and effective reduction of chemical oxygen demand (COD). The subsequent electrochemical process achieves the co-production of NH4 +-rich fertilizers and value-added chemicals, such as H2 as a green fuel and H2O2 as a disinfectant, without expensive ion-exchange membranes. These results provide a new conceptual strategy and insights for distributed electrochemical resource recovery and on-demand electrochemical manufacturing that can improve agricultural sustainability.

The Role of Transition Metals on Chemo‐Mechanical Instabilities in Prussian Blue Analogues For K‐Ion Batteries: The Case Study on KNHCF Versus KMHCF

AbstractPrussian blue analogues (PBAs) cathodes can host diverse monovalent and multivalent metal ions due to their tunable structure. However, their electrochemical performance suffers from poor cycle life associated with chemo‐mechanical instabilities. This study investigates the driving forces behind chemo‐mechanical instabilities in Ni‐ and Mn‐based PBAs cathodes for K‐ion batteries by combining electrochemical analysis, digital image correlation, and spectroscopy techniques. Capacity retention in Ni‐based PBA is 96% whereas it is 91.5% for Mn‐based PBA after 100 cycles at C/5 rate. During charge, the potassium nickel hexacyanoferrate (KNHCF) electrode experiences a positive strain generation whereas the potassium manganese hexacyanoferrate (KMHCF) electrode undergoes initially positive strain generation followed by a reduction in strains at a higher state of charge. Overall, both cathodes undergo similar reversible electrochemical strains in each charge–discharge cycle. There is ~0.80% irreversible strain generation in both cathodes after 5 cycles. XPS studies indicated richer organic layer compounds in the cathode‐electrolyte interface (CEI) layer formed on KMHCF cathodes compared to the KNHCF ones. Faster capacity fades in Mn‐based PBA, compared to Ni‐based ones, is attributed to the formation of richer organic compounds in CEI layers, rather than mechanical deformations. Understanding the driving forces behind instabilities provides a guideline to develop material‐based strategies for better electrochemical performance.

High crystallinity potassium nickel hexacyanoferrate nanoparticles synthesized by improved precipitation way as cathodes for potassium-ion batteries

Due to the unique three-dimensional tunnel structure, Prussian blue analogues can reversibly de/intercalate K+ in crystal lattice and show original electrochemical properties. However, crystal water and vacancy inevitably appear in the framework controlled by synthesis process, limiting severely the potassium storage. Herein, high crystallinity K1.86Ni[Fe(CN)6]0.87·□0.13·1.88H2O was synthesized through electrostatic assisted coprecipitation technology, which effectively increased the initial potassium content. Moreover, the microstructure is affected under the action of static electricity, resulting in a nano-structure and large specific surface area (102.5 m2 g−1). Compared with the sample without electrostatic field, its electrochemical performances can be significantly improved with a high initial coulombic efficiency of 85.5%, capacity retention of 90.3% after 503 cycles at 1C and rate capability of 49 mAh g−1 at 10C. The new method opens up a way for the performance improvement of other Prussian blue-based cathodes.

Structural characterization and Rietveld refinement of potassium nickel hexacyanoferrate {KNi[Fe(CN)6]} nano composites prepared via Co-precipitation method

Prussian Blue and its analogues based Nickel Hexacyanoferrate shows a number of application. Here we mixed potassium ion with nickel hexacyanoferrate and prepared Potassium Nickel Hexacyanoferrate to improve its applications. Prepared nano composites were synthesized by using Co-precipitation method. The structural analysis of prepared nano composite was studied by using X-Ray diffraction technique. Data comes out from X-Ray diffraction was refined through Rietveld method by using full prof suit software. Structure related other parameters were also studied here. The KNi[Fe(CN)6] shows FCC cubic structure with space group F m-3 m (225). Some measurement like Inter atomic distance, bond angle, half width, and lattice parameters were study in detail. The wyckoff position of different atom with site and S.O.F have been calculated. Infrared spectra of potassium Nickel hexacyanoferrate also are study here. Some application related to it in radioactive particle absorption from nuclear wastage and as an electrode in batteries. More applications of Potassium Nickel Hexacyanoferrate come into light on further research in this field.

Structure and properties of KNi–hexacyanoferrate Prussian Blue Analogues for efficient CO2 capture: Host–guest interaction chemistry and dynamics of CO2 adsorption

Potassium Nickel hexacyanoferrate Prussian Blue Analogues (K-NiFe-PBAs) offer an excellent platform for efficient CO2 capture due to their porous nature and accessible channels. Herein, the effect of Ni:K atomic ratio on the structure and the CO2 storage capacity was studied by employing K-NiFe-PBAs with Ni:K ratio of ca. 2.5 and 12. The porosity and the isosteric heat of CO2 adsorption can be modulated and optimized by varying the Ni:K atomic ratio in the PB framework and thus, covering the thermodynamic criterion for easy CO2capture and release with acceptable energy costs. The synthesized K-NiFe-PBAs containing only trace amounts of K+ ions (with Ni:K = 12) shows an adsorption capacity (∼3.0 mmol g–1 CO2 at 273 K and 100 kPa) comparable to other well established CO2 adsorbents. In situ FTIR spectroscopy was further employed to elucidate the host–guest interaction chemistry and the dynamics of K-NiFe-PBAs within CO2 and H2O. The analysis enabled, to the best of our knowledge, is the first FTIR spectroscopic observation of the high sensitivity of the material to structural distortions induced by small changes under water vapor pressure. It was found that H2O hardly affects CO2 adsorption and the materials are perspective for CO2 capture in the presence of water.

Radioactive Cs Removal from Aqueous Solutions by Biochar-Immobilized Potassium Nickel Hexacyanoferrate Prepared Using Ball Mill

Biochar-immobilized potassium nickel hexacyanoferrate (KNiFC) as a sorbent for removal of radioactive cesium (Cs) from aqueous solutions was prepared using a novel method. Japanese cedar sawdust loaded with NiSO4 using a ball mill was carbonized at various temperatures. The resultant Ni-loaded biochar was immersed in a K4[Fe(CN)6]·3H2O solution, and biochar-immobilized KNiFC was obtained. For comparison, Ni-loaded biochar was also prepared using the impregnation method. The loading of Ni using the ball mill resulted in a higher Ni amount in the biochar compared with the impregnation method. The carbonization at 400 °C was suitable for Cs adsorption on biochar and synthesis of KNiFC. Consequently, KNiFC immobilization on biochar improved the Cs sorption performance in aqueous solutions with Na+, K+, Ca2+, Mg2+, and Cs+. The sorption performance was selective in aqueous solutions with radioactive Cs and other cations of high concentration. Low-cost Cs adsorbent was prepared using a novel method from bioresource and KNiFC. The application of ball mill was effective for loading Ni on biochar. Immobilization of KNiFC on biochar improved Cs sorption performance. Removal of 134Cs and 137Cs using biochar-immobilized KNiFC was selective.

Remediation of cesium-contaminated fine soil using electrokinetic method

In this study, electrokinetic remediation equipment was used to remove cesium (Cs) from clay soil and waste solution was treated with sorption process. The influence of electrokinetic process on the removal of Cs was evaluated under the condition of applied electric voltage of 15.0-20.0 V. In addition to monitoring the Cs removal, electrical current and temperature of the electrolyte during experiment were investigated. The removal efficiency of Cs from soil by electrokinetic method was more than 90%. After electrokinetic remediation, Cs was selectively separated from soil waste solution using sorbents. Various adsorption agents such as potassium nickel hexacyanoferrate (KNiHCF), Prussian blue, sodium tetraphenylborate (NaTPB), and zeolite were compared and KNiHCF showed the highest Cs removal efficiency. The Cs adsorption on KNiHCF reached equilibrium in 30 min. The maximum adsorption capacity was 120.4 mg/g at 0.1 g/L of adsorbent dosage. These results demonstrated that our proposed process combined electrokinetic remediation of soil and waste solution treatment with metal ferrocyanide can be a promising technique to decontaminate Cs-contaminated fine soil.

RETRACTION: Application of a novel adsorbent prepared using magnetized Spirulina platensis algae modified by potassium nickel hexacyanoferrate for removal of cesium, studied by response surface methodology [C. R. Chimie, 2019, 22, no. 8, 562-573

RETRACTION: Application of a novel adsorbent prepared using magnetized Spirulina platensis algae modified by potassium nickel hexacyanoferrate for removal of cesium, studied by response surface methodology [C. R. Chimie, 2019, 22, no. 8, 562-573

CAESIUM RETENTION CHARACTERISTICS OF KNIFC-PAN RESIN FROM RIVER WATER.

The caesium retention characteristics of a potassium-nickel hexacyanoferrate resin in a polyacrylnitrile (KNiFC-PAN) matrix were tested in fresh water over the range of 2.5-400mLmin-1. The experimental setup used 2mL resin and 4-L aliquots of freshwater samples. The results showed nearly 100% retention at speeds below 10mLmin-1, above 80% up to 100mLmin-1, and approached 50% at 400mLmin-1. Using 100mLmin-1 flow rate and KNiFC-PAN resin in a well-type HPGe detector, the minimum detectable concentration was reduced to 3 mBq kg-1 for 4-L aliquots of water samples from the previous 15 mBq kg-1 achieved by Powdex ion-exchange resin and a planar type HPGe detector.

The Compensation Effect Mechanism of Fe-Ni Mixed Prussian Blue Analogues in Aqueous Rechargeable Aluminum-Ion Batteries.

An aluminum-ion battery was assembled with potassium nickel hexacyanoferrate (KNHCF) as a cathode and Al foil as an anode in aqueous electrolyte for the first time, based on Al3+ intercalation and deintercalation. A combination of ex situ XRD, X-ray photoelectron spectroscopy (XPS), galvanostatic intermittent titration technique (GITT), and differential capacity analysis was used to unveil the crystal structure changes and the insertion/extraction mechanism of Al3+ . Al3+ could reversibly insert/extract into/from KNHCF nanoparticles through a single-phase reaction with reduction/oxidation of Fe and Ni. Over long-term cycling, it was Fe rather than Ni that contributed to more capacity owing to the dissolution of Ni from the KNHCF structure, which could be expressed as a compensation effect of mixed redox centers in KNHCF. KNHCF delivered an initial discharge capacity of 46.5 mAh g-1 . The capacity decay could be attributed to the unstable interface between Al foil and the aqueous electrolyte owing to the catalytic activity of the Ni transferring from Ni dissolution of KNHCF to the Al foil anode, rather than KNHCF structure collapse; KNHCF maintained its 3 D framework structure for 500 cycles. This work is expected to inspire more exhaustive investigations of the mechanisms that occur in aluminum-ion batteries.

Investigation of caesium retention by potassium nickel hexacyanoferrate (II) in different pH conditions and potential effect on the selection of storage matrix

The chemical stability and caesium retention properties of a nonstoichiometric compoundK2-xNix/2[NiFe(CN)6].nH2O (KNiFCN) was studied in different pH conditions. Different solutions with controlled pH were prepared. Leaching tests were done with chemical analysis of the solutions. The compound was characterized before and after exposure by chemical analysis, SEM-BSE, X-ray diffraction and infrared spectroscopy. The face-centered cubic (FCC) structure of KNiFCN without caesium was stable even in presence of 1 g/l HNO3 (pH equal 2) or NaOH (pH equal 13). In presence of caesium trapped on KNiFCN structure, it appears that the increase in caesium content change the KNiFCN structure, thus influencing the retention properties in KNiFCN according to the pH of the solution. The KNiFCN structure was decomposed when the NaOH concentration exceeds 1 g/l (pH equal 14), probably due to the hydrolysis of constitutional elements. A selection of cementitious matrix is the proposed to satisfy stability conditions of this compound.

Potassium nickel hexacyanoferrate as cathode for high voltage and ultralong life potassium-ion batteries

Potassium-ion batteries (KIBs) are considered as one of the most promising energy storage devices owing to the close redox potential to lithium, rich abundance and low cost potassium resource, promoting the exploration on cathode materials for K-ions storage. This paper reports a detailed experimental study on potassium nickel hexacyanoferrate, K1.81Ni[Fe(CN)6]0.97·0.086H2O (KNHCF), cathode for KIBs. KNHCF synthesized possesses few [Fe(CN)6]4- vacancies and coordinated water molecules, and high specific surface area along with developed microporous/mesoporous structures, which collectively induce highly reversible electrochemical intercalation process and fast kinetics. The resultant KNHCF cathode demonstrates reversible capacity of 57.0 mAh·g−1, high operating voltage of 3.74 V, outstanding voltage stability with no decay, good cycling stability (87.34%) after 1000 cycles and long-term lifetime over 8000 cycles with capacity fading rate of 0.0052% per cycle. A solid solution mechanism with zero-strain, where one-electron shuttle relied on C-coordinated FeⅡ/FeⅢ couple, plays an important role for K-ions intercalation/deintercalation. A 3.34 V full cell assembled with graphite anode delivers a high energy density of 142.6 Wh·kg−1 with the cpacity retention of 88.5% after 100 cycles, and ultra-long life-span over 5000 cycles can be achieved.

RETRACTED: Application of a novel adsorbent prepared using magnetized Spirulina platensis algae modified by potassium nickel hexacyanoferrate for removal of cesium, studied by response surface methodology

This article has been retracted. Please see https://doi.org/10.5802/crchim.44

Offshore concentration of caesium radioisotopes from large volume seawater samples using KNiFC-PAN

A method for caesium concentration from North Sea and Baltic Sea seawater samples was tested and optimised for offshore concentration of radiocaesium and seawater volumes up to 150 L. The composite ion-exchanger PotassiumNickel Hexacyanoferrate in a Polyacrylnitrile binding matrix (KNiFC-PAN) with 80% of powdered KNiFC per gram of dry residue was used for this study. The optimised method achieved recoveries of around 99% with a bed volume (BV) of 50 mL of KNiFC-PAN and average flow rates of seawater of around 182 BV per hour (e.g. 9.1 L per hour).

Removal of Ag ﴾I﴿ ions using potassium nickel hexacyanoferrate ion exchanger incapsulated barium alginate from aqueous solutions.

Removal of Ag ﴾I﴿ ions using potassium nickel hexacyanoferrate ion exchanger incapsulated barium alginate from aqueous solutions.

Nanocomposite SiEA-KNiFe sorbent — Complete solution from synthesis through radiocesium sorption to vitrification using the sol–gel method

This study presents a novel complete solution starting with a synthesis of silica modified with potassium-nickel hexacyanoferrate and ethanolamine (SiEA-KNiFe) sorbent through radiocesium sorption in different process configurations and moving on to the vitrification of the spent sorbent, using the sol–gel method. The experimental data for deionized water solution, as well as seawater solution, correlates strongly with the Langmuir isotherm model. Moreover, the study also presents a method for spent sorbent solidification in the glass matrix. The cesium leaching test confirmed that spent sorbent can be stably bound in the glass matrix after radionuclide removal.

Hexacyanoferrate Cathode for Superior Na-Ion Batteries

Sodium iron hexacyanoferrate (Fe-HCF) is regarded as a potential cathode material for sodium-ion batteries (SIBs) due to its high specific capacity, low cost, facile synthesis and environmentally friendly. However, Fe-HCF always suffers from poor electronic conductivity, low crystallinity and side reactions with electrolyte, leading to poor rate performance, low coulombic efficiency and deterioration of cycling stability. Herein, we report the green and facile synthesis to encapsulate Fe-HCF microcubes with potassium nickel hexacyanoferrate (Ni-HCF) and PPy, separately, the surface modified Fe-HCF can exhibit excellent electrochemical performance as cathode in SIBs (Fig. 1). Firstly, the Fe-HCF@PPy composite exhibits a discharge capacity of 113.0 mA h g-1 at a current density of 25 mA g-1 and 75 mA h g-1 at 3000 mA g-1. Greatly improved cycling stability is attained with 79% capacity retention over 500 cycles at 200 mA g-1. The superior rate capability and excellent cyclability can be ascribed to the effects from PPy as both electronic conductor to enhance the conductivity and protective layer to prevent the side reactions. Secondly, the core-shell Fe-HCF@Ni-HCF composite delivers a reversible capacity of 79.7 mAh g-1 at 200 mA g-1 after 800 cycles and a high coulombic efficiency of 99.3 %. In addition, Fe-HCF@Ni-HCF exhibits excellent rate performance, retaining 60 mAh g-1 at 2000 mA g-1. The results show that Fe-HCF@Ni-HCF integrates the advantages of both Fe-HCF and Ni-HCF, making it electrochemically stable as cathode material for SIBs. Figure 1