Extraction Of Ions Research Articles

Insights into stripping losses of negative ions in an ITER-like pre-acceleration system

Abstract The ELISE test facility at IPP Garching hosts an RF-driven negative hydrogen ion source and extraction and acceleration system. Its target is to demonstrate the performance foreseen for the ITER neutral beam injection (NBI) system in terms of extracted current density (329A/m2 in hydrogen, 286A/m2 in deuterium), electron-ion-ratio (<1) and pulse length (up to 3600s in deuterium and 1000s in hydrogen). NBI systems are compromised by a process commonly known as stripping losses (i.e. neutralization of negative ions before they achieve full acceleration). According to theoretical estimations, for a source filling pressure of pfill=0.3Pa, 29\% of the extracted H-/D- ions are lost by stripping in the ITER full-scale NBI system. Experimentally, stripping losses are monitored using Beam Emission Spectroscopy (BES). Previous experimental measurements of the stripping losses at ELISE yielded values around 1.7\%, which were much lower than the 10\% predicted for the pre-accelerator system. The notable difference has sparked concern about the conventional interpretation of the BES experimental measurements used at IPP. The Bavarian Beam Code for Negative Ions (BBCNI) is a full 3D particle tracking code that can also produce synthetic BES spectra. BBCNI is used to evaluate how accurately different analysis techniques determine the stripping losses from the BES. This is achieved by comparing the results with the total simulated count of stripping losses. The analysis method that produces the most accurate results is identified and then systematically applied to evaluate ELISE's data from various experimental campaigns. For a nominal source filling pressure pfill=0.3Pa an average of 5.8\% is measured experimentally when evaluating the data with this method. Although higher than previously determined with BES, stripping losses are still smaller than predicted values. This may open the option to increase the filling pressure in the source as a means to facilitate achieving the targeted ITER conditions.

High efficiently removal of Cd(II) in environmental water samples by nano-particle supported ionic liquid material

Ionic liquids have been considered as green solvent for metal ion extraction. However, the high cost, low efficiency and hard phase separation limit their application. In this work, nano SiO2 supported ionic liquid (SiO2@NH-IL) prepared via simple homogeneous sol-gel method was used for adsorptive removal of Cd(II) from water sample. The material was characterized by XRD, TEM and FT-IR and zeta potential analysis. The adsorption kinetics, adsorption isotherm and reusability as well as the adsorption mechanism were investigated. The effects of solution pH and temperature were also studied. It was found that this nano-adsorbent could be used to remove trace level of Cd(II) efficiently due to the strong coordination of Cd(II) with the ionic liquid. Thermodynamic and kinetic studies showed that the adsorption rate increased with the increase of temperature, the maximum adsorption capacity was 112.13 mg g−1 at higher temperature (i.e. 80 °C), and the adsorption equilibrium could achieve in 30 min. The nano-adsorbent could be easily regenerated by 0.5 mol L−1 of HCl and reused as least ten adsorption/desorption cycles. The as-prepared nano-adsorbent are potential candidate for adsorptive removal of Cd(II) in polluted wastewater, especially with higher temperature.

Structure-Function Insights into Thermoresponsive Copolymers as Lanthanide Precipitants.

The synthetic toolbox for stimuli-responsive polymers has broadened to include many tunable variables, making these materials applicable in diverse technologies. However, unraveling the key composition-structure-function relationships to facilitate ground-up design remains a challenge due to the inherent dispersity in sequence and conformations for synthetic polymers. We here present a systematic study of these relationships using a model system of copolymers with a thermoresponsive (N-isopropylacrylamide) backbone in addition to metal-chelating (acrylic acid) and hydrophobic structural comonomers and evaluate their efficiency at isolating technologically critical lanthanide ions. The efficiency of lanthanide ion extraction by precipitation was quantitated with a metallochromic dye to reveal trends relating copolymer hydrophobicity to improved separations. Further, we examined the role of different hydrophobic comonomers in dictating the solution-phase conformation of the polymer in the presence and absence of lanthanide ions, and we correlated key features of the hydrophobic comonomer to extraction efficiency. Finally, we identified how the local proximity of thermoresponsive, chelating, and hydrophobic subunits facilitates metal extraction by manipulating the copolymer sequence with multiblock polymerization. Through mechanistic analysis, we propose a binding-then-assembly process through which metal ions are coprecipitated with macromolecular chelators.

Theoretical Analysis and Case Studies of One-Dimensional Ion Extraction Processes

Theoretical Analysis and Case Studies of One-Dimensional Ion Extraction Processes

Particle-stabilized foams with fatty acid salts as stabilizers triggered by transition metal ions

Particle-stabilized foams have been becoming the focus on foaming field because of their excellent stability due to the high stiffness of interface membrane. However, the modification of particle surfaces to reach an appropriate wettability needs complicated process, resulting in accompanied inconvenient foaming-defoaming regulation. In this work, we reported a series of foams stabilized by insoluble particles generated from fatty acid anions with metal ions. Different hydrocarbon chains endowed the formed particles diverse wettability and different aggregation behaviors at the gas–liquid interface, e.g., different foamability and the formation of the “dry water”. The foams exhibited ultra-stable properties and were responsive to environmental acidity, thus possessing a smart foaming-defoaming transition tuned by pH. The combination ability of fatty acid anions with metal ions changed with the chain-length and the nature of metal ions, leading to a choice for the extraction or separation of some metal ions in a fast and simple way. This new aggregation behavior of fatty acid salts can be explored to expand the practical applications.

Structure-performance relationship and molecular structure optimization design of acid phosphate ester extractants

The extraction performance of acid phosphate ester extractants (PEEs) decreases significantly as the acidity of the aqueous phase increases. Therefore, finding PEEs suitable for high-acid environments has become critical to addressing their performance attenuation. However, the unclear structure-performance relationship of PEEs has led to a lack of guidance in experimental synthesis, significantly impeding the emergence of new acid-resistant PEEs. To tackle these issues, ten novel phenyl phosphate ester extractants were designed based on the molecular formula of phosphodiester (R1R2P(=O)OH) and the conjugation effect of the benzene ring. The relationship between the intrinsic extraction performance of acid PEEs and substituent groups (phenoxy, alkoxy, and alkyl) was quantitatively established by calculating the Gibbs free energy changes of three primary reactions (dimer dissociation, monomer acid ionization, and metal coordination) during divalent cobalt ion extraction. Additionally, the impact of different substitution sites (para, meta, and ortho) of the benzene ring on the extraction performance of acid PEEs was studied. The results indicated that introducing phenoxy groups into traditional acid PEEs (P204 and P507) can effectively enhance the extractants’ acid ionization ability and thermodynamic driving force. The extraction performance of acid PEEs is positively correlated with the number of phenoxy groups, and carbon chain substitution at the meta-position of the benzene ring is the most advantageous. By screening five low-toxicity and low-cost phenolic hydroxyl reagents currently available on the market, design a phenyl phosphate ester extractant ([(CH3)3CCH2C(CH3)2C6H4O]2P(=O)OH, P-4TO) that combines cost and performance advantages. Furthermore, the transition state theory was used to confirm the feasibility of preparing P-4TO, which provided a comprehensive theoretical research method for the future design and synthesis of efficient PEEs.

Metal ions extraction in the ammonium sulfate–oxyethylated nonylphenol (neonol AF 9-10)–water system in the presence of organic complexing agents

Metal ions extraction in the ammonium sulfate–oxyethylated nonylphenol (neonol AF 9-10)–water system in the presence of organic complexing agents

Influence of the Structure of Carbamoylmethylphosphine Oxides on the Extraction of Lanthanides(III) from Nitric Acid Solutions in the Presence of Dinonylnaphtalenesulfonic Acid

It was found that the extraction of lanthanides(III) from nitric acid solutions with solutions of carbamoylmethylphosphine oxides increases significantly in the presence of dinonylnaphthalene sulfonic acid. The stoichiometry of the extracted complexes was determined, and the influence of the composition of the aqueous phase, the nature of the organic solvent, and the structure of carbamoylmethylphosphine oxides on the efficiency of extraction of metal ions into the organic phase was considered.

Synergistic effect of molybdenum dioxide wrapped nitrogen doped carbon nanotubes in binder-free anodes for enhanced lithium storage properties

Molybdenum dioxide (MoO2) is regarded as a potential anode for lithium-ion batteries due to its highly theoretical specific capacity. However, its further application in lithium-ion battery is largely limited by insufficient practical discharge capacity and cyclic performance. Here, MoO2nanoparticles are in-situ grown on three-dimensional nitrogen doped carbon nanotubes (NCNTs) on nickel foam substrate homogeneously using a simple electro-deposition method. The unique structural features are favorable for lithium ions insertion and extraction and charge transfer dynamics at electrode/electrolyte interface. As a proof of concept, the as-synthesized nanocomposites have been employed as anode for lithium-ion battery, exhibiting a reversible and significantly improved discharge capacity of ∼517 mA h g-1at the current density of 150 mA g-1as well as superior cycle and rate performance. The first-principle calculations based on density functional theory and electrochemical impedance spectroscopy results demonstrate a reduced energy barrier of lithium ions diffusion, improved lithium storage behavior, reduced structure collapse, and significantly enhanced charge transfer kinetics in MoO2/NCNTs nanocomposites with respect to MoO2powder. The excellent performance makes as-prepared MoO2/NCNTs nanocomposites promising binder-free anode for high performance lithium-ion batteries. This work also provides important theoretical insights for other state-of-the-art batteries design.

Cloud point extraction of heavy metal ions for wastewater remediation: an equilibrium and kinetic study

Abstract Surfactants offer a promising alternative for the efficient and environmentally friendly removal of organic pollutants and toxic heavy metal ions from various media. Their high efficiency and environmental compatibility make them a valuable option for remediation efforts. This study focuses on the cloud point extraction (CPE) of ions from aqueous solutions using biodegradable nonionic surfactants combined with ionic surfactants instead of chelating agents. Phase diagrams of binary surfactant/water systems were first constructed. The effects of salt, inorganic contaminants, and ionic surfactants on the cloud point (Tc) were then investigated. At temperatures above the cloud point, two distinct phenomena were observed and monitored over time: phase separation and phase clarification. The kinetic process was studied using the Turbiscan Lab Expert. Extraction results were evaluated based on four responses: extraction yield (E%), residual concentrations of solute (Xs,w) and surfactant (Xt,w) in the dilute phase, and volume fraction of coacervate at equilibrium (Φ C). Empirical modelling gives a satisfactory agreement between experimental and calculated values. The capacity of CPE to simultaneously remove an organic pollutant and a toxic heavy metal was demonstrated.

Solvent Extraction of Gallium and Germanium Using a Novel Hydroxamic Acid Extractant

The rare metals gallium and germanium are key strategic metals that are widely used in emerging industries. In this work, a novel hydroxamic acid extractant, BGYW, with low toxicity, was used for the selective solvent extraction of Ga ions and Ge ions from Zn, As, Cu, and Al ions in the solution from zinc smelting. The gallium and germanium ions were extracted efficiently under optimized conditions. Gallium ions were preferentially stripped using sulfuric acid, and germanium ions were stripped using an ammonium fluoride solution. Compared with the commercial extractant YW100, the dissolution loss of BGYW was reduced by 10 times. After 15 cycles, the germanium solvent extraction efficiency of BGYW remained at 100%, and the solvent extraction efficiency of gallium was about 98.7%, while the solvent extraction efficiency of both Ga ions and Ge ions using YW100 decreased to 20% after five cycles. This novel solvent extraction system exhibits considerable promise for application in zinc smelting processes for gallium and germanium solvent extraction.

Preparation of amorphous TiO2 films by RF magnetron sputtering: Process optimization and effect of sputtering pressure on electrochromic properties

In this study, radio frequency (RF) magnetron sputtering was utilized to fabricate Titanium dioxide (TiO2) thin films at a room temperature. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, electrochemical workstation, and UV–Vis spectrophotometry were employed to analyze and characterize the microstructure, compositional components, and electrochromic properties of the films. The main focus is on exploring the microstructure and electrochromic properties of films produced under diverse sputtering pressures. The results show that the TiO2 films fabricated at a sputtering pressure of 1.2 Pa exhibit the most desirable surface morphology, with an optical modulation amplitude of up to 49.18 % (@550 nm), coloring time of 1.28 s, bleaching time of 0.79 s, and a coloration efficiency of 21.07 cm2/C. After 1000 cyclic voltammetry tests, the Q decay rate is 51.75 %. Electrochemical impedance spectroscopy (EIS) measurements reveal that TiO2 films prepared under these process parameters have lower charge transfer resistance and ion diffusion impedance, which facilitate ion injection and extraction.

Functionalization of magnetic beads with chelating surfactants for metal ions extraction

Divalent amino acid-based surfactants were utilized in the preparation and functionalization of polystyrene/superparamagnetic iron oxide nanoparticle (SPION) beads. These surfactants were derived from aminomalonic acid, aspartic acid, and glutamic acid, all containing two carboxylic groups and differing only in the spacer size between these groups, coupled with a fatty acid moiety, resulting in N-acyl amino acid surfactants. In the process of beads formation, the surfactant played a dual role as a stabilizer and a chelating agent towards the targeted metal. The beads were obtained using an emulsion solvent evaporation method. In this process, an oil-in-water emulsion was formed, containing polystyrene and iron nanoparticles. By concentrating the oil and evaporating it, solid nanoparticles were obtained. The morphology of these particles was characterized using atomic force microscopy (AFM), dynamic light scattering (DLS), while streaming potential measurements were used to determine their charge density. The surfactant's capability to extract divalent ions, specifically Zn2+ and Ni2+, was assessed both in its pure form and when they were attached to the particles. The aspartate-based surfactant showed the best chelating performance for divalent ions, and the combination of surfactant-functionalized particles with magnetic responsiveness led to highly efficient extraction (up to 90 %) results. Additionally, the recyclability of the beads was also assessed, highlighting their practical utility.

Synthesis and Evaluation of the Extraction Efficiency of Pristine Zeolite Na-A to Remove ReO4- Ions (Surrogate of 99TcO4-) from a Simulated Low-Level Waste Solution.

Zeolite Na-A was synthesized through hydrothermal, alkali-fusion, and sonochemical methods, using kaolin as an economically viable precursor. The synthesized zeolite Na-A samples were characterized using XRD, FT-IR, SEM, and Raman spectroscopy. Specific surface area and pore size distribution analyses (by BJH and DFT models) were conducted using a BET surface area analyzer. Additionally, thermal degradation studies were performed by TG-DTA to check the thermal stability of zeolite Na-A at high temperatures. Furthermore, kaolin-derived zeolite Na-A was employed for the extraction of perrhenate ions (ReO4-), which are a nonradioactive surrogate for pertechnetate ions (99TcO4-) without any postsynthetic modifications (using toxic surfactants, etc.) utilizing in situ modification of the solution medium for the first time. The sonochemically synthesized zeolite Na-A demonstrated superior sorption performance for the solid-phase extraction of ReO4- ions from the simulated low-level waste solution. The adsorption process was found to follow pseudo-second-order kinetics. The Langmuir isotherm model fit perfectly with the experimental data (R2 = 0.997) and exhibited a maximum sorption capacity of 926.8 mg/g at pH ∼11, showing superior sorption capacities compared to those of the numerous materials reported earlier. XPS confirmed the speciation of extracted rhenium as NH4Re(VII)O4, providing critical insights into the adsorption mechanisms and validating the suitability of the sonochemically synthesized zeolites toward ReO4- sorption. Furthermore, Raman studies of ReO4- adsorbed zeolite Na-A reflect the absence of characteristic breathing bands, indicating the closure of the pore openings due to the occupancy of adsorbate moieties within the pores. This study not only highlights the utilization of sonochemically synthesized zeolite Na-A as an efficient, benign, and cost-effective adsorbent for 99TcO4- removal from nuclear waste but also emphasizes its potential sustainable applications in various other industrial processes such as wastewater treatment, catalysis, gas separation, pollution control, and resource recovery from industrial effluents and in the pharmaceutical industry for selective ion removal.

ITER-relevant 600 s steady-state extraction of negative hydrogen ions at the test facility ELISE

Abstract The neutral beam heating system for the future international fusion experiment ITER will be based on RF driven ion sources delivering a large (≈1×2 m2) and homogeneous negative hydrogen or deuterium ion beam of several ten Amperes over up to several hundred seconds. The size scaling experiment ELISE (Extraction from a Large Ion Source Experiment) is an integral part of the R&D road-map towards the ITER neutral beam heating system. Recently, 90 % of the ITER target for the extracted current density was achieved in hydrogen for 600 s, increasing the pulse length over that such current densities are possible by a factor of more than ten. For ten second beam pulses the ITER target current density was achieved. These breakthrough results are made possible by a steady-state capable HV power supply together with an improved version of internal potential rods and a modified topology of the magnetic filter field.

Numerical Simulation of Autoresonant Ion Oscillations in an Anharmonic Electrostatic Trap.

This work presents the results of modeling the ion dynamics in the ART-MS (Autoresonant Trap Mass Spectrometry) device in the quasi-static approximation. This instrument utilizes an anharmonic, purely electrostatic trap for ion confinement and a radio frequency (RF) voltage source with decrementally varying frequency for selective ion extraction. The autoresonant interaction between the oscillatory motion of the ion and the RF voltage increases the amplitude of some confined ions, allowing their selective extraction. Numerical modeling shows that the extraction of ions with a given mass occurs not only at the fundamental frequency but also at its harmonics. This effect reduces the selective properties of devices of this type because along with the main mass component for a given frequency, it is possible to enter the detector channel of ions with another mass, for which this frequency corresponds to the second or higher harmonics, even a superposition of some of these harmonics of different ions.

Fluorous and Organic Extraction Systems: A Comparison from the Perspectives of Coordination Structures, Interfaces, and Bulk Extraction Phases.

Microscopic structures in liquid-liquid extraction, such as structuration between extractants or extracted complexes in bulk organic phases and at interfaces, can influence macroscopic phenomena, such as the distribution behavior of solutes, including extraction efficiency and selectivity. In this study, we correlated the macroscopic behavior of the Zr(IV) extraction from nitric acid solutions with microscopic structural information to understand at the molecular level the key factors contributing to the higher metal ion extraction performance in the fluorous extraction system as compared to the analogous organic extraction system. The fluorous and organic extraction systems consist of tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) phosphate (TFP) in perfluorohexane and tri-n-heptyl phosphate (THP) in n-hexane, respectively. Extended X-ray absorption fine structure, neutron reflectometry (NR), and small-angle neutron scattering revealed the structural information around the central metal ion of the complex, at the interface, and in the bulk extraction phase, respectively. NR results showed that extractant molecules did not accumulate much at the interface in both extraction system. In the fluorous extraction system, extractant aggregates with a 1.46 nm radius of gyration (Rg) were formed after contact with nitric acid, and remained even after Zr(IV) extraction through the form of a 1:3 (Zr(IV):TFP) complex. In contrast, in the organic extraction system, only extractant dimers with Rg of 0.70 nm were formed and Zr(IV) is extracted through the form of a 1:2 (Zr(IV):THP) complex. We speculate that differences in the local coordination structure around the Zr(IV) ion and the structuration of the extractant molecules in the bulk extraction phase contribute to the high Zr(IV) extraction performance in the fluorous extraction system. In particular, the size of the aggregates hardly changed with increasing Zr(IV) concentration in the fluorous phase, which may be closely related to the absence of phase splitting in the fluorous extraction system.

2D Electrodes From Functionalized Graphene for Rapid Electrochemical Gold Extraction and Reduction From Electronic Waste.

Electronic waste (e-waste) contains substantial quantities of valuable precious metals, particularly gold (Au). However, inefficient metal recovery leads to these precious metals being discarded in landfills, causing significant water and environmental contamination. This study introduces a two-dimensional (2D) electrode with a layered graphene oxide membrane functionalized by chitosan (GO/CS). The GO/CS membrane acts as an ion-selective layer and demonstrates capabilities in the electrochemical extraction and reduction of Au ions. The multiple functional groups of GO and CS offer high cooperativity in ion extraction and reduction, achieving 95wt.% extraction efficiency within 10min. The simultaneous extraction and electrocatalytic reduction of Au ions within the membrane leads to the formation of ready-to-use metallic Au forms such as chips and sensors. Such an approach eliminates the processing steps required to convert extracted gold into functional products, reducing time, cost, and energy. This direct formation of usable Au components enhances the efficiency of the recovery process, making it economically viable and environmentally sustainable. The gold mining market is projected to be valued at $270 billion by 2032, with the recycling segment reaching $10.8 billion, highlighting the substantial benefits and economic potential of efficient e-waste recycling technologies.

Deep Learning Enhanced in Situ Atomic Imaging of Ion Migration at Crystalline-Amorphous Interfaces.

Improving the performance of energy storage, neuromorphic computing, and more applications requires an in-depth understanding of ion transport at interfaces, which are often hindered by facile atomic reconfiguration at working conditions and limited characterization capability. Here, we construct an in situ double-tilt electric manipulator inside an aberration-corrected scanning transmission electron microscope. Coupled with deep learning-based image enhancement, atomic images are enhanced 3-fold compared to traditional methods to observe the potassium ion migration and microstructure evolution at the crystalline-amorphous interface in antimony selenide. Potassium ions form stable anisotropic insertion sites outside the (Sb4Se6) chain, with a few potassium ions present within the moieties. Combined experiments and density functional theory calculations reveal a reaction pathway of forming a novel metastable state during potassium ion insertion, followed by recovery and unexpected chirality changes at the interface upon potassium ion extraction. Our unique methodology paves the way for facilitating the improvement and rational design of nanostructured materials.

Enhancing Charge–Discharge Speed of Li-Ion Batteries with BaTiO3-Coated LiCoO2

Lithium-ion batteries experience a decrease in capacity as the charge–discharge speed increases. To enhance the charge–discharge speed characteristics, the surface of the LiCoO2 (LCO) cathode material was coated with ferroelectric BaTiO3 (BT) nanodots. The electric field concentration phenomenon occurs at the triple-phase interface of LCO-BT-electrolyte due to the polarizing characteristics of the ferroelectric system. BT coated on the LCO surface acts as a protective layer and promotes the insertion and extraction of Li ions, resulting in a discharge capacity of 131.9 mAh g−1 at 10 C. This value is approximately 333% higher than that of bare LCO, and it enables stable cycling of LCO even at a cut-off voltage of 4.5 V. The study’s findings suggest that coating LCO with BT nanodots can significantly improve the charge–discharge performance of lithium-ion batteries, making them more efficient for high-speed charging applications in portable electronics and electric vehicles.