Radius Of Metal Ion Research Articles

Predicting Room‐Temperature Conductivity of Na‐Ion Super Ionic Conductors with the Minimal Number of Easily‐Accessible Descriptors

Given the vast compositional possibilities , Na‐ion superionic conductors are attractive but complicated for designing materials with enhanced room‐temperature Na‐ion conductivity . An explicit regression model for with easily‐accessible descriptors is proposed by exploiting density functional theory molecular dynamics (DFT‐MD). Initially, it is demonstrated that two primary descriptors, the bottleneck width along Na‐ion diffusion paths and the average Na–Na distance , modulate room‐temperature Na‐ion self‐diffusion coefficient . Then, two secondary easily‐accessible descriptors are introduced: Na‐ion content n, which influences , , and Na‐ion density ; and the average ionic radius of metal ions, which impacts and . These secondary descriptors enable the development of a regression model for with n and only. Subsequently, this model identifies a promising yet unexplored stable composition, , which, upon DFT‐MD calculations, indeed exhibits S cm−1. Furthermore, the adjusted version effectively fits experimental values with .

Geometric Tuning of Coordinatively Unsaturated Copper(I) Sites in Metal-Organic Frameworks for Ambient-Temperature Hydrogen Storage.

Porous solids can accommodate and release molecular hydrogen readily, making them attractive for minimizing the energy requirements for hydrogen storage relative to physical storage systems. However, H2 adsorption enthalpies in such materials are generally weak (-3 to -7 kJ/mol), lowering capacities at ambient temperature. Metal-organic frameworks with well-defined structures and synthetic modularity could allow for tuning adsorbent-H2 interactions for ambient-temperature storage. Recently, Cu2.2Zn2.8Cl1.8(btdd)3 (H2btdd = bis(1H-1,2,3-triazolo-[4,5-b],[4',5'-i])dibenzo[1,4]dioxin; CuI-MFU-4l) was reported to show a large H2 adsorption enthalpy of -32 kJ/mol owing to π-backbonding from CuI to H2, exceeding the optimal binding strength for ambient-temperature storage (-15 to -25 kJ/mol). Toward realizing optimal H2 binding, we sought to modulate the π-backbonding interactions by tuning the pyramidal geometry of the trigonal CuI sites. A series of isostructural frameworks, Cu2.7M2.3X1.3(btdd)3 (M = Mn, Cd; X = Cl, I; CuIM-MFU-4l), was synthesized through postsynthetic modification of the corresponding materials M5X4(btdd)3 (M = Mn, Cd; X = CH3CO2, I). This strategy adjusts the H2 adsorption enthalpy at the CuI sites according to the ionic radius of the central metal ion of the pentanuclear cluster node, leading to -33 kJ/mol for M = ZnII (0.74 Å), -27 kJ/mol for M = MnII (0.83 Å), and -23 kJ/mol for M = CdII (0.95 Å). Thus, CuICd-MFU-4l provides a second, more stable example of optimal H2 binding energy for ambient-temperature storage among reported metal-organic frameworks. Structural, computational, and spectroscopic studies indicate that a larger central metal planarizes trigonal CuI sites, weakening the π-backbonding to H2.

Highly efficient adsorption of aqueous heavy metals by Co-derived metal-organic framework. Synergistic mechanism for enhanced water purification

This study opens up exciting possibilities for the application of Co-MOF, a Metal-Organic Framework ([Co(5-NH2-bdc)(bpy)0.5(H2O)]3·2H2O), in the efficient removal of heavy metals (Pb2+, Hg2+, Cd2+, Cu2+) from water. The removal mechanism combines ion exchange and adsorption, influenced by the ionic radius of the metal ions. Langmuir's model determined maximum adsorption capacities (Qm), showing a proportional increase with the ionic radius of heavy metals: 75.47 mg/g (Cu2+), 344.82 mg/g (Cd2+), 485 mg/g (Hg2+), and 526.31 mg/g (Pb2+). Free Gibbs energy, inversely proportional to the metal's ionic radius, was determined as −36.43 kKj/mol (Cu2+), −28.67 Kj/mol (Cd2+), −24.13 Kj/mol (Pb2+), and −21.67 Kj/mol (Hg2+). The pseudo-second-order mechanism explained heavy metal removal, except for Cu2+, due to continuous ion exchange. Reutilization experiments showed a decrement in efficacy in the second cycle. Filtration experiments demonstrated a lower removal percentage (close to 60 %) and confirmed the competitive activity of Co-MOF compared to other MOFs, particularly in Cd2+ removal, with superior rate constants and maximum adsorption capacities.

Computational and experimental investigations on structural, electronic and optical properties of scheelite compounds

Oxide of tungstate has consistently been pursued for use in optoelectronic applications. This study details the synthesis of AWO4 (A = Ba, Sr and Ca) using a high-temperature solid-state method. Additionally, theoretical calculations highlight its electronic structure, density of states, photoelectric properties, and vibrational modes. The x-ray diffraction of AWO4 (A = Ba, Sr and Ca) was meticulously introduced by the utilization of Rietveld for refinement. The refined lattice parameters substantially verified AWO4 (A = Ba, Sr and Ca) as a tetragonal system of scheelite with the spatial group of I41/a, and demonstrated significant alteration with the discrepancy in the radius of alkaline earth metal (A-site) ions. The electronic configuration and optical attributes of AWO4 (A = Ba, Sr and Ca) possessing scheelite-like structure were explored using density functional theory (DFT) based computational techniques. The theoretical blueprint was derived by optimizing the structure based on defects. The postulated optical bandgap energy confirms the occurrence of direct electronic transitions at Brillouin region G points. Calculations suggested the direct band gaps of BaWO4, SrWO4, and CaWO4 at 4.385, 3.123 and 3.813 eV. This was attributed to the energy levels produced by O and A-site atoms in the valence band, and W and O atoms in the conduction band. An examination of the polarization effect and uneven electronic charge distribution between [CaO8]6− and [WO4]2− clusters brought about by structural defects in AWO4 (A = Ba, Sr and Ca) was performed. Moreover, advanced investigations have been conducted on the elastic constants and mechanical durability of AWO4 (A = Ba, Sr and Ca). This research extensively calculated the elastic moduli of various matrices utilizing DFT. The critical Pugh’s ratio value was found to be >1.75, it indicated that AWO4 (A = Ba, Sr and Ca) has significant potential as a resilient material.

Blue fluorescent waterborne polyurethane‐based transition metal complexes with antibacterial activity

AbstractEfficient and stable blue fluorescent materials are the key components of light‐emitting devices and have received wide attention. Herein, transition metal complexes Zn(5‐AQ)2, Cu(5‐AQ)2, and Cd(5‐AQ)2 are prepared by using 5‐aminoquinoline (5‐AQ) as ligand and Zn2+, Cu2+, and Cd2+ as the central ions, respectively. Then, waterborne polyurethane (WPU)‐based transition metal complexes Zn(5‐AQ)2‐WPU, Cu(5‐AQ)2‐WPU, and Cd(5‐AQ)2‐WPU with different emission wavelengths of blue fluorescence are prepared by bonding Zn(5‐AQ)2, Cu(5‐AQ)2, and Cd(5‐AQ)2 to polyurethane chains as chain extenders, respectively. Noteworthily, with the increase of transition metal ion radius (Zn2+ < Cu2+ < Cd2+), the fluorescence emission wavelengths of the complexes showed different degrees of blue‐shift, and the blue‐shifted wavelengths showed a decreasing trend. Importantly, their fluorescence colors are blue‐shifted from blue‐green to blue with different emission wavelengths after accessing the polyurethane backbone, which has potential applications in the field of tuning white LED materials. The thermal decomposition temperatures of Zn(5‐AQ)2‐WPU, Cu(5‐AQ)2‐WPU, and Cd(5‐AQ)2‐WPU are above 220°C with good thermal stability, and their fluorescence lifetimes are prolonged by 8.817, 8.896, and 6.489 ns, respectively, compared with the complexes. Furthermore, WPU transition metal complexes with water as a dispersive medium have an antibacterial efficiency of up to 100% against Escherichia coli, which is an environmentally friendly antibacterial material with broad application prospects.

Comparison of microwave and conventional pyrolysis of one-step prepared metal soaps (Li/Na/K/Ca/Mg): Product distribution and heating characteristics

The pyrolysis of metal soaps to produce hydrocarbon rich fuel has been studied extensively. However, the combined effects of microwave radiation and metal ion types on hydrocarbon production have not been addressed. In this study, the microwave and conventional pyrolysis experiments were conducted on five metal soaps (Li soap, Na soap, K soap, Ca soap, Mg soap). The results demonstrated that the metal ions at the carboxyl end of the soap enhanced the polarity of the reactants, leading to a rapid increase in temperature under microwave conditions. With the ion radius increasing, the heating rate increased gradually. Compared with conventional pyrolysis, microwave pyrolysis exhibited a more rapid heating rate, a higher degree of carbon chain fracture, and a greater abundance of small olefin compounds, which promoted aromatization reaction and the release of CO, H2 and CH4. In addition, the composition of the pyrolysis products derived from different metal soaps is affected by the characteristics of metal ions. As the radius of metal ions increased, the oxygen content in the liquid products decreased gradually, while the carbon content increased. The strengthening effect of microwave was further analyzed. With the increase in the radius of metal ions, the strengthening effect of microwaves on olefins formation was gradually weakened, while the inhibiting effect on alkanes formation was gradually enhanced. The structure of carboxylate network is affected by the radius of metal ions, which results in the regular change of the strengthening effect of microwave on olefins and other products. This study is highly significant in guiding the pyrolysis of soapstock waste to prepare olefins and alkanes with high efficiency and low energy consumption.

Non-Aqueous Rechargeable Rb-O2 Batteries

Li-O2 batteries have attracted increasing attention because their theoretical energy density exceeds that of current lithium-ion batteries.[1] Generally, the positive electrode reaction in nonaqueous alkali metal-O2 batteries proceeds through oxygen reduction and corresponding reoxidation, forming alkali metal superoxide (MO2) as the discharge product. It is known that the stability of the superoxide (MO2) depends on the relationship between the ionic radius of the alkali metal ion (M+) and the superoxide ion (O2 −).[2] For example, LiO2 consists of small Li+ (ionic radius in octahedral coordination: 0.76 Å) and relatively large O2 − (1.49 Å), resulting in its short lifetime and rapid disproportionation reaction; 2LiO2 → Li2O2+O2. As the two-electron reduction product, Li2O2, exhibits a large overpotential to re-oxidize it, Li-O2 cells are known to have low reversibility.[1] On the other hand, NaO2 is relatively stable because the ionic radius of Na+ (1.02 Å) is relatively large compared to that of Li+. Thus, Na-O2 battery is also promising due to the low charge overpotential of the one-electron reduction product, NaO2. However, NaO2 is highly reactive with a trace amount of moisture, CO2, and electrolyte components, partially forming Na2O2 and/or its hydrates.[3] Further stabilization was observed by using K+ (1.38 Å) to form KO2, thus K-O2 cell is known to have high stability and reversibility as well as low overpotential.[4] Following these trends, in this study, we focused on Rb+ (1.52 Å), which has a similar ionic radius to O2 − (1.49 Å), and investigated the electrochemistry of oxygen reduction and evolution reaction in Rb-containing non-aqueous electrolytes.The working electrode is prepared by mixing Ketjen black (KB) and polytetrafluoroethylene (PTFE) in a weight ratio of 80:20, followed by coating it on carbon paper. The counter electrode consists of activated carbon, KB, and PTFE mixed with an 80:10:10 weight ratio. Ag+/Ag reference electrode and rubidium bis(trifluoromethanesulfonyl)amide (RbTFSA)/ triglyme (G3) electrolytes were also used to fabricate three-electrode O2-cell. The cells were first assembled in an Ar-filled glove box, followed by purging dry-O2 gas to supply an adequate amount of O2 in the cell. Note that Rb metal was not used for safety reasons.Figure (a) presents the charge-discharge curves obtained with 1 mol/dm3 RbTFSA/G3 electrolyte under a dry-O2 and dry-Ar atmosphere. While no capacity was observed under the Ar atmosphere, distinct plateaus appeared at 2.57 and 2.67 V (vs. Rb+/Rb) at discharge and charge sequence, respectively, under the O2 atmosphere. A discharge capacity of ~0.6 mAh cm−2 and a relatively small overpotential of 100 mV were achieved, as well as high Coulombic efficiency at the initial cycle of 71 %. Figure (b) shows XRD patterns of pristine and fully discharged electrodes, where all of the new peaks that appeared through discharge reaction can be assignable to RbO2. Therefore, the discharge product of the Rb-O2 cell is confirmed to be RbO2, similar to Na-O2 and K-O2 cells. The reaction mechanism, reversibility, and stability of the O2/RbO2 electrode will be presented and discussed.Reference:[1] P. Bruce, J-M. Tarascon, et al., Nat. Mater., 11, 19-29 (2012).[2] L. Qin, Y. Wu, et al., J. Am. Chem Soc., 142, 11629 (2020).[3] P. Hartmann, P. Adelhelm, et al., Nat. Mater., 12, 228 (2013).[4] X. Ren, Y. Wu, J. Am. Chem. Soc., 2, 2923 (2013). Figure 1

A new insight into the pseudo-second-order model and the physical meaning of its rate constant in adsorption

In this research, an exact mathematical expression for the rate constant of the pseudo-second-order (PSO) model was obtained based on the general rate equation related to the adsorption mechanism of Coleman et al. This expression is capable of accurately calculating the ionic radius of divalent metal ions adsorbed on the adsorbent surface. It was also shown that the PSO model is more accurate under the conditions of low adsorbent dosage, low specific surface area of adsorbent, high molecular weight of adsorbate, and equilibrium coverage fraction close to 1. The validity of the obtained results was confirmed through experimental data selected from the literature.

Effect of alkaline-earth metal ion radius on the coordination number and proton conductivity of isomorphous MOFs

Differences in metal ions in isomorphous MOFs for modulating proton conductivity are an interesting and meaningful topic. In order to investigate how differences in the radii of homologous metal ions affect the amount of coordinated water in MOFs and control the continuity of the hydrogen bonding network, the monocarboxylic tetrazolium organic ligand HL (5-(2-pyridyl)tetrazole-2-acetic acid) was used to construct two isomeric MOFs M(L)2(H2O)2 (M = Mg: MOF-Mg; M = Ca: MOF-Ca), which have only two coordinated waters per metal and discontinuous hydrogen bonding hopping paths. The same ligand was used to construct two isomeric MOFs [M2(L)4(H2O)6]·2H2O (M = Sr: MOF-Sr; M = Ba: MOF-Ba), which have three coordinated waters per metal and a continuous hydrogen-bonding hopping path, resulting in a high proton conductivity of 1.28 × 10−3 S cm−1 at 65 °C and 98% RH for MOF-Ba which is over 4000 times that of MOF-Ca. The proton conductivity mechanism was calculated to be a Grotthuss mechanism and verified by the deuterium-hydrogen isotopic effects. Moreover, the proton conductivity was maintained for more than 72 h without any obvious decrease.

Cover Picture

The cover picture depicts two oxide cluster, Lu2O and Er2O, nested in the robust Cs(6)‐C82 fullerene cage, respectively. Their crystallographic structures display a large variation in the angles of the clusters within the cage (146.74° vs. 116.51°), suggesting flexible configurations of the oxide clusters heavily dependent on the radius of encapsulated metal ions. This work discloses the role of metal species in adjusting cluster conformation, and facilitates the understanding of interplay between the encapsulated cluster and host cage. More details are discussed in the article by Lu et al. on page 1915—1920.image

OLIVINE-BASED SORBENTS FOR REMOVAL OF HEAVY METALS

Inductively coupled plasma mass spectrometry (ISP-MS) and scanning electron microscope-X-ray fluorescence (SEM-XRF) methods were used for the investigation of olivine sorption properties. It has been shown, that olivine may be applied as a cheap and available material for the sorption of metals, including heavy metals, from wastewater. The comparatively low sorption capacity of olivine may pay off by its accessibility and cheapness. The mechanism of adsorption on the olivine surface may be described as the substitution of magnesium ions by cations of various metals. One trend can be fixed – when ionic radius of the metal cations increases, their sorption increases as well. However, it is hardly possible to tie everything with the ionic radius of metal ion. The specificity of each element is also important.

Crystallographic Characterization of Lu2O@Cs(6)‐C82 and Er2O@Cs(6)‐C82: The Role of Metal Species on Cluster Configuration†

Comprehensive SummaryIntramolecular interactions are fundamental for the unique structures and outstanding properties of metallofullerenes. However, how the internal metal species interplay with the cluster configuration inside oxide clusterfullerenes remains poorly understood. Herein, we successfully captured two oxide clusterfullerenes with different metals, namely, Lu2O@C82 and Er2O@C82, to elucidate the role of metal species in tuning cluster configuration. The two molecules have been fully characterized by mass spectrometry, Vis‐NIR absorption spectroscopy, cyclic voltammetry, and single‐crystal X‐ray diffraction. Crystallographic data show that their isomeric cages were both determined as Cs(6)‐C82. Further structural analysis reveals that the Lu1‐O‐Lu2 angle value in Lu2O@Cs(6)‐C82 is much larger than the Er1‐O‐Er2 angle value in Er2O@Cs(6)‐C82, indicating that the configuration of the endohedral oxide clusters is flexible and dependent on the metal ion radius. Additionally, electrochemical studies suggest that the variation in entrapped metal species causes differences in redox properties, for which the first oxidation and first reduction potentials of Lu2O@Cs(6)‐C82 are shifted positively and negatively, respectively, compared to the counterparts of Er2O@Cs(6)‐C82, resulting in a larger electrochemical band‐gap.

Novel Metal Complexes Unit of Phenanthroline Derivative for Being Used as Auxiliary Electron Acceptor in Dye Sensitizer Molecules

AbstractDonor‐acceptor‐π bridge‐acceptor (D−A−π−A) motif dyes are promising dye sensitizers in dye‐sensitized solar cells (DSSCs). In this study, to strengthen with‐drawing electron force of the auxiliary electron acceptors(A) in D−A−π−A motif dye sensitizers, the metal complexes unit is be used as auxiliary electron acceptor(A) instead of organic electron‐withdrawing monomer. The four polymeric metal complexes were designed, synthesized, and characterized, which used metal complexes of phenanthroline derivatives as auxiliary acceptors (A), benzodithiophene‐dithiophene derivatives (BDTT) as donors (D), and 8‐hydroxyquinoline derivatives as π‐bridges and acceptors of the dye sensitizers, and have been used for dye sensitizers. Under AM 1.5 G (100 mW cm−2), the photovoltaic test results indicated that the short‐circuit photocurrent density (Jsc) of the DSSCs based four polymeric metal complexes are 11.26, 13.68, 14.42 and 15.57 mA cm−2and power conversion efficiency (PCE) are 5.96 %, 7.83 %, 8.07 %, 9.28 % respectively. BothJscandPCEvalue of the four polymeric metal complexes increased in order. This may be due to the fact that larger radius of metal ion under the same change number can enhance the coordination bond and cause stronger electron‐withdrawing ability of auxiliary acceptor and stronger charge‐transfer ability between the donor and the acceptor, which results in higherJscand higherPCEof the polymeric complex dye sensitizer.

Effects of alkali-metals (X = Li, Na, K) doping on the electronic, optoelectronic, thermodynamic, and X-ray spectroscopic properties of X–SnI3 halide perovskites

The effect of alkali metals (Li, Na, K) doping at X sites in tin-based X–SnI3 halide perovskite on structural, electronic, phonon, thermodynamic, and X-ray core-level spectroscopic properties was investigated and correlated with optoelectronic efficiency in the development of a stable and environmentally friendly solar technology to replace toxic lead-based perovskite solar cells (PSCs). These calculations were carried out based on the density functional theory approach using the Quantum Espresso software with the generalized gradient approximation (GGA) exchange correlation Perdew Burke Ernzerhorf functional. In addition, the phonon frequency, thermodynamics, and X-ray spectroscopy calculations were completed in Materials Studio using the CASTEP code. Our results reveal that there is a clear correlation between the alkali metal's ionic radius, changes in the lattice structural parameters, and the electronic band gap, such that the lattice constants are 5.940, 5.868, and 5.897 Å and the band gaps are 1.20, 1.14, and 1.10 eV for LiSnI3, NaSnI3, and KSnI3, respectively. The highest lattice constant obtained for LiSnI3, indicates that Li atoms occupied interstitial positions in the perovskite crystal, whereas the direct band gap decreases as cationic size increases, with KSnI3 exhibiting the least band gap. Phonon calculations show that KSnI3 has the lowest negative vibration region in its phonon dispersion plot, indicating dynamic stability. Interestingly, all the structures are found to portray high optical absorption, high extinction coefficient, high polarizability. Additionally, the free energy computation of the perovskites shows a reduction with rising temperature, but enthalpy increases significantly with increasing temperature. Yet, due to phonon lattice vibrations, the heat capacity increased as the temperature rose. Although the XSnI3 (X = Li, Na, and K) perovskites under investigation will perform efficiently as semiconductors and can be used for optoelectronic applications, the KSnl3 perovskite material has the most desirable properties for the fabrication of solar cell devices.

Study on the influence mechanism of mineral components in biochar on the adsorption of Cr(VI)

Cr(VI) is extremely harmful to the ecological environment. The secondary purification method of treating low concentrations is not satisfactory currently. In this paper, wheat straw were pyrolyzed at 800 °C to obtain biochar, which were used to explore the effect of minerals on adsorption effect as a precursor at different pH and 25 °C. The biochar was gradually eluted with HCl and HF to remove the ash, soon loaded with K+, Ca2+, Mg2+ and Fe3+, respectively. The results show that under the action of H+, the CO bonds left after mineral removal have lower potential energy than the original surface functional groups in terms of conversion to –OH and binding to Cr. The order of promotion of Cr(VI) adsorption by the four elements is Fe3+> Mg2+＞ Ca2+> K+. As the radius of metal ions decreases, so does the electronegativity of biochar and the surfactive site increases. The adsorption mechanisms of alkali metals, alkaline earth metals and transition metals to Cr(VI) are mainly based on ion exchange, precipitation and complexation, respectively. The adsorption of Cr(VI) by wheat straw biochar was consistent with the quasi-secondary kinetic model. Combined with the results of intraparticle diffusion model fitting, it shows that this process is a multi-stage adsorption process with the combined effect of physical and chemical adsorption.

Effect of the metal ion radius on the structure of SrII—ZnII and SrII—CdII complexes with cyclobutane-1,1-dicarboxylate anions

Effect of the metal ion radius on the structure of SrII—ZnII and SrII—CdII complexes with cyclobutane-1,1-dicarboxylate anions

Mixed Metal Phosphonates: Structure and Proton Conduction Manipulation through Various Alkaline Earth Metal Ions

Three new layered mixed metal phosphonates [CoMg(notpH2)(H2O)2]ClO4·nH2O (CoMg·nH2O), [Co2Sr2(notpH2)2(H2O)5](ClO4)2·nH2O (CoSr·nH2O), and [CoBa(notpH2)(H2O)1.5]ClO4 (CoBa) were synthesized by reacting a tripodal metalloligand CoIII(notpH3) [notpH6 = C9H18N3(PO3H2)3] with alkaline earth metal ions. Along with an increase in the radius of the alkaline earth metal ions, the 6-coordinate {MgO6}, 7-coordinate {SrO7}, and 9-coordinate {BaO9} geometries are the distorted octahedron, capped triangular prism, and tricapped triangular prism, respectively. Consequently, the metalloligand Co(notpH2)− adopts variable coordination modes to bind the alkaline earth metal nodes, forming diverse layer topologies in the three mixed metal phosphonates. The AC impedance measurements revealed that the proton conductivities at 25 °C and 95% relative humidity (RH) follow the sequence: CoMg·nH2O > CoSr·nH2O > CoBa. As expected, CoMg·nH2O exhibits a 28-fold enhanced value for proton conductivity (4.36 × 10−4 S cm−1) compared with the previously reported isostructural compound, CoCa·nH2O, at 25 °C and 95% RH due to the greater Lewis acid strength of Mg(II) lowering the pKa of the coordinated water.

Modeling phytoremediation of heavy metal contaminated soils through machine learning

As an important subtopic within phytoremediation, hyperaccumulators have garnered significant attention due to their ability of super-enriching heavy metals. Identifying the factors that affecting phytoextraction efficiency has important application value in guiding the efficient remediation of heavy metal contaminated soil. However, it is challenging to identify the critical factors that affect the phytoextraction of heavy metals in soil–hyperaccumulator ecosystems because the current projections on phytoremediation extrapolations are rudimentary at best using simple linear models. Here, machine learning (ML) approaches were used to predict the important factors that affecting phytoextraction efficiency of hyperaccumulators. ML analysis was based on 173 data points with consideration of soil properties, experimental conditions, plant families, low-molecular-weight organic acids from plants, plant genes, and heavy metal properties. Heavy metal properties, especially the metal ion radius, were the most important factors that affect heavy metal accumulation in shoots, and the plant family was the most important factor that affect the bioconcentration factor, metal extraction ratio, and remediation time. Furthermore, the Crassulaceae family had the highest potential as hyperaccumulators for phytoremediation, which was related to the expression of genes encoding heavy metal transporting ATPase (HMA), Metallothioneins (MTL), and natural resistance associated macrophage protein (NRAMP), and also the secretion of malate and threonine. New insights into the effects of plant characteristics, experimental conditions, soil characteristics, and heavy metal properties on phytoextraction efficiency from ML model interpretation could guide the efficient phytoremediation by identifying the best hyperaccumulators and resolving its efficient remediation mechanisms.

Co-extraction of Mn2+, Co2+, and a part of Ni2+ from sulfuric acid solution containing Li+ using the new ionic liquids

In this study, five novel ionic liquids denoted by [RNH3][Cyanex 272] where R = C4H9, C6H13, C8H17, C10H21, and C12H25 were synthesized in a one-step reaction of straight-chain primary amines and Cyanex 272. The singe-stage extraction performance of [RNH3][Cyanex 272] for the separation of Mn2+, Co2+, Ni2+ and Li+ was investigated. Compared with the other [RNH3][Cyanex 272], the [C4H9NH3][Cyanex 272] has good selective extraction and separation of Mn2+, Co2+, and Ni2+ due to the smaller different value between the radius of metal ion and the radius of [C4H9NH3]+. Using a three-stage cross flow extraction, the extraction percentages of Mn2+, Co2+, Ni2+, and Li+ were about 99.4, 99.1, 14.9 and 0.9 %. The [C4H9NH3][Cyanex 272] is a good extraction agent for co-extraction of Mn2+, Co2+, and a part of Ni2+ from Li+ based on a three-stage cross flow extraction. Diluted sulfuric acid was used to strip the organic phase containing Mn2+, Co2+, and Ni2+, and the aqueous phase containing Mn2+, Co2+, and Ni2+ can be used for the preparation of ternary precursor materials. The precipitation method can be used to prepare Ni(OH)2 and Li2CO3 from an aqueous phase containing Ni2+ and Li+. The conceptual recycling flow-sheet for Mn2+, Co2+, Ni2+, and Li+ from spent ternary lithium batteries was presented on basis of the new extraction agent. The slope method was also used to investigate the mechanism of the extractive reaction of Mn2+, Co2+, and Ni2+ using the [C4H9NH3][Cyanex 272].

Strain-induced magnetic anisotropy of REIG thin films grown on YAG(111) substrates by pulsed laser deposition

Several studies have revealed using rare earth (RE) elements instead of yttrium to regulate the strain-induced magnetic anisotropy of garnet films in recent years. In this study, we used pulsed laser deposition to fabricate RE iron garnet (REIG) thin films on (111)-oriented yttrium aluminum garnet (YAG) substrates. The REIG films are 100 nm in thickness and crystalline with (111)-orientation. The out-of-plane (444)-plane spacing decreases as the ionic radius of RE metal ions decreases, while the crystallite size increases. Samarium, holmium, and yttrium iron garnet (SmIG, HoIG, and YIG) have out-of-plane compressive strain, while erbium and thulium iron garnet (ErIG and TmIG) have weak out-of-plane tensile strain. The strain of the REIG films is resulted from lattice mismatch, off-stoichiometry, and the recrystallization process by thermal annealing. SmIG has a rather rough surface because of the crystalline distortion due to the largest ionic radius of Sm and the lattice mismatch between SmIG and YAG substrates. Due to negative magnetostriction constant and out-of-plane compressive strain, SmIG and HoIG films show strong perpendicular magnetic anisotropy (PMA) in vibrating sample magnetometry and magneto-optical Faraday effect (MOFE). MOFE also revealed that the REIG films have different sensitivities at different wavelengths of light. With further tuning PMA on SmIG and HoIG by decreasing the thickness and lateral size, our findings could pave the way for high-density nano-scale magnetic information storage based on REIG thin films.