Quaternary Metal Research Articles

Sol-Gel Based Synthesis of LiNiFeF6 and Its Electrochemical Characterization

Lithium transition metal oxides are commonly used as cathode materials in modern mobile and stationary power supplies. Lithium transition metal fluorides are an interesting new class of materials for lithium ion batteries featuring a higher voltage due to substitution of oxygen by the more electronegative fluorine. A sol-gel based process with trifluoroacetic acid as fluorine source was used to synthesize LiNiFeF6. Ball-milling with carbon and binder was applied to obtain an electrochemical active LiNiFeF6/carbon/binder nano composite. In this study we report on the first electrochemical characterization of a quaternary lithium transition metal fluoride as positive electrode for lithium ion batteries, containing two different transition metals. After 20 cycles of galvanostatic cycling a reversible specific capacity of 88 mAh/g, which is 92% of the initial specific capacity, was retained. In a rate performance test with rates of up to 1C a reversible capacity of 53 mAh/g was obtained. The electrochemically active redox couple Fe3+/Fe2+ was identified by Mössbauer spectroscopy and cyclic voltammetry.

Enabling Solar Fuels Technology With High Throughput Experimentation

ABSTRACTThe High Throughput Experimentation (HTE) project of the Joint Center for Artificial Photosynthesis (JCAP, http://solarfuelshub.org/) performs accelerated discovery of new earth-abundant photoabsorbers and electrocatalysts. Through collaboration within the DOE solar fuels hub and with the broader research community, the new materials will be utilized in devices that efficiently convert solar energy, water and carbon dioxide into transportation fuels. JCAP-HTE builds high-throughput pipelines for the synthesis, screening and characterization of photoelectrochemical materials. In addition to a summary of these pipelines, we will describe several new screening instruments for high throughput (photo-)electrochemical measurements. These instruments are not only optimized for screening against solar fuels requirements, but also provide new tools for the broader combinatorial materials science community. We will also describe the high throughput discovery, follow-on verification, and device implementation of a new quaternary metal oxide catalyst. This rapid technology development from discovery to device implementation is a hallmark of the multi-faceted JCAP research effort.

Programmed Pore Architectures in Modular Quaternary Metal–Organic Frameworks

To generate metal-organic frameworks (MOFs) that are complex and modular yet well ordered, we present a strategy employing a family of three topologically distinct linkers that codes for the assembly of a highly porous quaternary MOF. By introducing substituted analogues of the ligands, a set of eight isoreticular frameworks is delivered, with the MOF structure systematically varied while the topology is maintained. To combat randomness and disorder, the substitution patterns of the ligands are designed to be compatible with their crystallographic site symmetries. MOFs produced in this way feature "programmed pores"--multiple functional groups compartmentalized in a predetermined array within a periodic lattice--and are capable of complex functional behavior. In these examples unconventional CO2 sorption trends, including capacity enhancements close to 100%, emerge from synergistic effects. Future PP-MOFs may be capable of enzyme-like heterogeneous catalysis and ultraselective adsorption.

Y2MoSe3O12 and Y2MoTe3O12: Solid-state synthesis, structure determination, and characterization of two new quaternary mixed metal oxides containing asymmetric coordination environment

Two new quaternary yttrium molybdenum selenium/tellurium oxides, Y2MoSe3O12 and Y2MoTe3O12 have been prepared by standard solid-state reactions using Y2O3, MoO3, and SeO2 (or TeO2) as reagents. Single-crystal X-ray diffraction was used to determine the crystal structures of the reported materials. Although both of the materials contain second-order Jahn–Teller (SOJT) distortive cations and are stoichiometrically similar, they reveal different structural features: while Y2MoSe3O12 shows a three-dimensional framework consisting of YO8, MoO6, and SeO3 groups, Y2MoTe3O12 exhibits a layered structure composed of YO8, MoO4, TeO3, and TeO4 polyhedra. With the Mo6+ cations in Y2MoSe3O12, a C3-type intraoctahedral distortion toward a face is observed, in which the direction of the out-of-center distortion for Mo6+ is away from the oxide ligand linked to a Se4+ cation. The Se4+ and Te4+ cations in both materials are in asymmetric coordination environment attributed to the lone pairs. Elemental analyses, infrared spectroscopy, thermal analyses, intraoctahedral distortions, and dipole moment calculations for the compounds are also presented.

Predicting the toxicity of metal mixtures

The toxicity of single and multiple metal (Cd, Cu, Pb, and Zn) solutions to trout is predicted using an approach that combines calculations of: (1) solution speciation; (2) competition and accumulation of cations (H, Ca, Mg, Na, Cd, Cu, Pb, and Zn) on low abundance, high affinity and high abundance, low affinity biotic ligand sites; (3) a toxicity function that accounts for accumulation and potency of individual toxicants; and (4) biological response. The approach is evaluated by examining water composition from single metal toxicity tests of trout at 50% mortality, results of theoretical calculations of metal accumulation on fish gills and associated mortality for single, binary, ternary, and quaternary metal solutions, and predictions for a field site impacted by acid rock drainage. These evaluations indicate that toxicity of metal mixtures depends on the relative affinity and potency of toxicants for a given aquatic organism, suites of metals in the mixture, dissolved metal concentrations and ratios, and background solution composition (temperature, pH, and concentrations of major ions and dissolved organic carbon). A composite function that incorporates solution composition, affinity and competition of cations for two types of biotic ligand sites, and potencies of hydrogen and individual metals is proposed as a tool to evaluate potential toxicity of environmental solutions to trout.

Trends in formation energies and elastic moduli of ternary and quaternary transition metal nitrides

The paper deals with characteristics of a wide range of ternary and quaternary metal nitrides (M = Ti, Zr, Hf, V, Nb or Ta) of various compositions obtained by ab initio calculations. We focus on the formation energies (Eform), bulk moduli (B), shear moduli (G) and a difference of B and G from the weighted average of B and G of binary metal nitrides (∆B and ∆G). We show numerous monotonous dependencies, and identify exceptions to them. For elastic moduli of M1M2N we find that ∆B decreases (down to −19 GPa) and ∆G increases (up to 20 GPa) with increasing difference between atomic radii of M1 and M2. In parallel, low ∆B and high ∆G correspond to high Eform and |Eform|, respectively. Eform of M1M2N increases with increasing difference between atomic radii and electronegativities of M1 and M2. The lowest Eform values were observed for Ta-containing compositions, and the difference between Eform of TaM1M2N and M1M2N is more significant for lower atomic radius and higher electronegativity of M1 and M2. Overall, we present trends which allow one to use fundamental arguments (such as atomic radii and electronegativities) to understand and predict which compositions form (nano)composites, which compositions form (stable) solid solutions, and which materials exhibit enhanced elastic moduli. The phenomena shown can be tested experimentally, and examined for even wider range of materials.

Structural Characterization and Physical Properties of the New Transition Metal Oxyselenide La2O2ZnSe2

The quaternary transition metal oxyselenide La(2)O(2)ZnSe(2) has been shown to adopt a ZrCuSiAs-related structure with Zn(2+) cations in a new ordered arrangement within the [ZnSe(2)](2-) layers. This cation-ordered structure can be derived and described using the symmetry-adapted distortion mode approach. La(2)O(2)ZnSe(2) is an direct gap semiconductor with an experimental optical band gap of 3.4(2) eV, consistent with electronic structure calculations.

Chelate resin self-assembled quaternary Co–N–P–C catalyst for oxygen reduction reaction

The Co–N–P–C composite is synthesized via a facile chelate resin method and its oxygen reduction reaction (ORR) activity is studied for the first time. The aminophosphonic acid chelate resin can easily coordinate with Co2+ to uniformly form an interlinked macromolecular network containing a Co–N–P–C structure. The Co–N–P–C, as a quaternary non-precious metal catalyst, displays better ORR activity in acidic media compared with Co–N–C. The material shows high stability with an onset potential of 0.98 V and a well-defined limiting current plateau for the ORR in acidic media. This method to prepare the Co–N–P–C catalyst is scalable to meet industrial requirements.

Ternary and quaternary metal chalcogenide nanocrystals: synthesis, properties and applications

We review the field of multinary metal chalcogenide nanocrystals, which has gained strongly increasing interest in the quest for novel narrow band gap semiconductors. Small (2–4 nm) CuInS2 and CuInSe2 nanocrystals, for example, exhibit size dependent luminescence in the visible and near infrared range. Their quantum yield can exceed 50% after growth of a ZnS shell, which makes them appealing emitters for lighting, displaying and biological imaging applications. Cu2ZnSnS4 (CZTS) nanocrystals, on the other hand, can be used as solution processed absorbing materials in thin film solar cells showing high power conversion efficiencies (currently around 8–10%). These examples illustrate that multinary metal chalcogenide nanocrystals have high potential for replacing classical cadmium and lead chalcogenide quantum dots in many fields. We give an overview of the chemical synthesis methods of the different systems reported to date, classifying them according to the obtained crystal structure. Next, we discuss their photophysical properties and give a brief description of the main fields of application. Finally, we conclude by outlining current challenges and related future directions of this exponentially growing domain.

Multiple Equilibria and Chemical Distribution of Some Bio Metals With β-Amide α-Aminosuccinate And α - Aminoisoverate as Primary Ligand and 5-Methyl 2, 4 Dioxopyrimidine as Secondary Ligand

Solution Chemistry of some bivalent metal ions (viz. Co II , Ni II ,Cu II ,Zn II ) with β-amide α- aminosuccinate (Asparagine)/ α-aminoisoverate( Valine ) (A) and 5-methyl 2,4- dioxopyrimidine ( Thymine ) (B)ligands have been analyzed. Formation constant of quaternary metal complexes and complexation equilibria at 30±1oC and at constant ionic strength (I=0.1M NaNO3 ) have been explored potentiometrically. Formation of quaternary species in addition to hydroxyl, protonated, binary and ternary species have been reported. Overall formation constant have been evaluated using SCOGS computer program.Species distribution curves of complexes have been plotted as a function of pH to visualize the equlibria system and was refined using ORIGIN program.The metal ligand formation constant of MA,MB,MAB and M1M2AB type of complexes follow Irving William order. The order of stability constants of quaternary systems have been observed as: Cu - Ni > Cu -Zn > Cu-Co > Ni - Zn > Ni - Co > Co -Zn. Solution structures of metal complexes with said ligands have been compared and discussed.

Chemical welding of binary nanoparticles: room temperature sintering of CuSe and In2S3 nanoparticles for solution-processed CuInSxSe1−x solar cells

Chemical welding of oppositely charged dissimilar metal chalcogenide nanomaterials is reported to produce a quaternary metal chalcogenide. CuSe and In2S3 nanoparticles were synthesized with opposite surface charges by stabilizing with polyacrylic acid and polydiallyldimethylammonium chloride. Upon mixing these nanoparticles at room temperature, the electrostatic attraction induced coalescence of these nanoparticles and led to the formation of CuInSxSe1-x nanoparticles.

Atomic Layer Deposition of the Quaternary Chalcogenide Cu2ZnSnS4

Atomic layer deposition (ALD) is a layer-by-layer synthesis method capable of depositing conformal thin films with thickness and compositional control on subnanometer length scales. While many materials have been synthesized by ALD, the technologically important metal sulfides are underexplored, and homogeneous quaternary metal sulfides are absent from the literature. We report an ALD process to synthesize Cu2ZnSnS4 (CZTS), a potentially low cost semiconductor being explored for photovoltaic applications. Two strategies are reported: one in which a trilayer stack of binary metal sulfides (i.e., Cu2S, SnS2 and ZnS) is deposited and mixed by thermal annealing, as well as a supercycle strategy that is similar to the conventional ALD procedure for forming nanolaminates. Both routes rely on the facile solid state diffusion of chalcogenides for mixing. For this ALD route to the CZTS system, the challenges are nucleation, ion-exchange between the film and the volatile chemical precursors, and phase-stability of binary SnS2. The thin films were made with no sulfurization step. The X-ray diffraction and Raman spectra were consistent with the formation of CZTS. X-ray fluorescence measurements revealed that the films contained the expected amount of sulfur based on the target oxidation states. Photoelectrochemical measurements under simulated AM1.5 illumination using Eu3+ as an electron acceptor demonstrated that the films were photoactive and had an average internal quantum efficiency (IQE) of 12%.

Synthesis and characterization of a novel quaternary metal chalcogenide-Hg3ZnSe3Br2

A novel quaternary metal chalcogenide Hg3ZnSe3Br2 (1) was prepared via a solid-state reaction method and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the space group P-3 of the hexagonal system with two formula units in a cell: a = 7.383(7) A, c = 10.924(9) A, V = 515.6(8) A3, FW = 1063.84, Dc = 6.852 g/cm3, S = 0.713, μ(MoKα) = 65.083 mm−1, F(000) = 884, R = 0.1377 and wR = 0.2720. Compound 1 is characterized by a 2-D layered motif, which is constructed from the interconnected 12-membered Hg6Br6 rings with a chair-like conformation.

Effect of the Framework Flexibility on the Centricities in Centrosymmetric In2Zn(SeO3)4 and Noncentrosymmetric Ga2Zn(TeO3)4

The solid-state syntheses, crystal structures, and characterization of two stoichiometrically similar quaternary mixed metal selenite and tellurite, In(2)Zn(SeO(3))(4) and Ga(2)Zn(TeO(3))(4), respectively, are reported. While In(2)Zn(SeO(3))(4) crystallizes in the centrosymmetric monoclinic space group P2(1)/n (No. 14) with a = 8.4331(7) Å, b = 4.7819(4) Å, c = 14.6583(13) Å, and β = 101.684(6)°, Ga(2)Zn(TeO(3))(4) crystallizes in the non-centrosymmetric space group I-43d (No. 220) with a = b = c = 10.5794(8) Å. In(2)Zn(SeO(3))(4) exhibits a two-dimensional crystal structure consisting of distorted InO(6) octahedra, ZnO(6) octahedra, and SeO(3) polyhedra. Ga(2)Zn(TeO(3))(4) shows a three-dimensional framework structure that is composed of GaO(4) or ZnO(4) and TeO(3) polyhedra. An effect of the framework flexibility on the space group centricity is discussed. The SHG (second harmonic generation) efficiency of noncentrosymmetric Ga(2)Zn(TeO(3))(4), using 1064 nm radiation, is similar to that of KH(2)PO(4) (KDP) and is not phase-matchable (Type 1). Complete characterizations including infrared spectroscopy and thermal analyses for the reported materials are also presented, as are dipole moment calculations.

The new oxosilicate NaTbSi2O6: A comparison of its A- and D-type structure

Two different modifications of the composition NaTbSi 2 O 6 were synthesized within the class of quaternary alkali-metal rare-earth metal(III) oxosilicates. Monoclinic NaTbSi 2 O 6 (A-type structure: space group P 2 1 /c (no. 14); a = 542.57(4), b = 1376.54(9), c = 762.83(5) pm, β = 110.086(3)°, V m = 80.557(9) cm 3 /mol, Z = 4) crystallizes isotypically with NaYSi 2 O 6 und LiScSi 2 O 6 . In this ino -oxosilicate, the [SiO 4 ] 4– tetrahedra are vertex-shared and linked to form infinite zigzag chains ∞ 1 {[SiO 2/2 v O 2/1 t ] 2– } along [001]. Both, the Na + and the Tb 3+ cations are coordinated by seven O 2– anions each. The [TbO 7 ] 11– polyhedra get connected via trans -oriented edges to build up ∞ 1 {[TbO 4/2 e O 3/1 t ] 7– } chains running along [001], which alternate with the ∞ 1 {[SiO 2/2 v O 2/1 t ] 2– } chains. In contrast, triclinic NaTbSi 2 O 6 with a novel D-type structure (space group: P -1 (no. 2), a = 549.41(4), b = 938.65(6), c = 972.30(7) pm, α = 117.263(2), β = 97.239(2), γ = 99.676(2)°, V m = 85.798(9) cm 3 /mol, Z = 3) belongs to the cyclo -oxosilicates according to Na 3 Tb 3 [Si 6 O 18 ] with Z = 1. The arrangement of the resulting corrugated six-membered [Si 6 O 18 ] 12– rings of vertex-shared [SiO 4 ] 4– tetrahedra is similar to a hexagonal closest packing parallel to (100). The two types of distorted [TbO 6 ] 9– octahedra are linked along [010] via common edges to form undulated infinite ∞ 1 {[TbO 4/2 v O 2/1 t ] 5– } chains, which become alternatingly piled with the cyclo -[Si 6 O 18 ] 12– units and the incorporated Na + cations along [010]. While the square-pyramidally coordinated (Na2) + cations are situated between the isolated cyclo -oxohexasilicate anions, the sixfold coordinated (Na1) + cations can be found inside the rings. They are therefore surrounded by the six bridging O 2– anions of the cyclo -[Si 6 O 18 ] 12– units in a quasi -planar hexagonal coordination sphere.

Hierarchical Assembly of Multifunctional Oxide-based Composite Nanostructures for Energy and Environmental Applications

Composite nanoarchitectures represent a class of nanostructured entities that integrates various dissimilar nanoscale building blocks including nanoparticles, nanowires, and nanofilms toward realizing multifunctional characteristics. A broad array of composite nanoarchitectures can be designed and fabricated, involving generic materials such as metal, ceramics, and polymers in nanoscale form. In this review, we will highlight the latest progress on composite nanostructures in our research group, particularly on various metal oxides including binary semiconductors, ABO3-type perovskites, A2BO4 spinels and quaternary dielectric hydroxyl metal oxides (AB(OH)6) with diverse application potential. Through a generic template strategy in conjunction with various synthetic approaches— such as hydrothermal decomposition, colloidal deposition, physical sputtering, thermal decomposition and thermal oxidation, semiconductor oxide alloy nanowires, metal oxide/perovskite (spinel) composite nanowires, stannate based nanocompostes, as well as semiconductor heterojunction—arrays and networks have been self-assembled in large scale and are being developed as promising classes of composite nanoarchitectures, which may open a new array of advanced nanotechnologies in solid state lighting, solar absorption, photocatalysis and battery, auto-emission control, and chemical sensing.

Thermal stability of TiZrAlN films deposited by a reactive magnetron sputtering method

Quaternary TiZrAlN films are: • perspective for both oxidation and wear resistance applications and expectant substitution for TiN, (Ti,Al)N and (Ti,Zr)N hard films; • capable to possess by the unique properties due to possibility of nanocomposite structure formation during their synthesis. The aim of the present work is to study the thermal stability, under vacuum and air annealing, of quaternary transition metal nitride films, namely (Ti,Zr)1-xAlxN, with emphasis on the role of Al content on the structure and phase formation.

PbMSeO6 (M = Mo and W): New quaternary mixed metal selenites with asymmetric cationic coordination environments

Two new isostructural mixed metal selenites, PbMSeO(6) (M = Mo(6+) or W(6+)), that are only composed of second-order Jahn-Teller (SOJT) distortive cations have been synthesized by standard solid-state reaction techniques using PbO, SeO(2), and MoO(3) (or WO(3)) as reagents. The structures of the reported materials were determined by single-crystal and powder X-ray diffraction. The materials show a three-dimensional framework structure consisting of chains of corner-shared MO(6) octahedra connected by SeO(3) and PbO(8) polyhedra. All of the constituent cations (M(6+), Se(4+), and Pb(2+)) are in distorted environments attributable to second-order Jahn-Teller (SOJT) effects. While the Mo(6+) cations undergo a C(2)-type intraoctahedral distortion toward an edge, the Se(4+) and Pb(2+) cations are in asymmetric coordination environments attributable to their lone pairs. The SeO(3) polyhedra strongly influence the direction of the Mo(6+) intraoctahedral distortion. Infrared spectroscopy, thermogravimetric analysis, the magnitudes of out-of-center distortions, and dipole moment calculations are also presented. Crystal data: PbMoSeO(6), triclinic, space group P-1 (No. 2), with a = 6.8944(6) Å, b = 7.2219(6) Å, c = 10.8294(9) Å, α = 99.751(2)°, β = 99.996(2)°, γ = 90.041(2)°, V = 523.09(8) Å(3), and Z = 2; PbWSeO(6), triclinic, space group P-1 (No. 2), with a = 6.8689(2) Å, b = 7.2398(2) Å, c = 10.9037(3) Å, α = 99.699(4)°, β = 100.348(3)°, γ = 90.139(4)°, V = 525.50(3) Å(3), and Z = 2.

Equilibrium sorption study of Cr (VI) from multimetal systems in aqueous solutions by Lyngbya putealis

This article extends the study on the treatment of industrial effluent by considering the competitive biosorption in tertiary and quaternary metal system (cadmium, lead, nickel and chromium), by an indigenously isolated cyanobacterial strain, Lyngbya putealis HH-15 isolated from metal contaminated site. The effect of the presence of other metal ions on chromium biosorption were investigated in terms of equilibrium isotherms and results indicated that the uptake capacity of biosorbent is influenced by the number and type of metal ions in solution. The Langmuir model was found to be better applicable to the experimental data as compared to Freundlich as inferred from high value of coefficient of determination. On the basis of experimental results and model parameters, it can be inferred that the biosorbent which has quite high biosorption capacity in single metal system can still be utilized for the removal of chromium from aqueous solution in the presence of other metals like cadmium, lead and nickel, though with a reduced efficiency.

Electrochemical inactivation of Bacillus spores in drinking water using a quaternary oxide electrode

Bacillus spores are resistant to disinfection methods and they represent a potential threat that requires improved methods to ensure water safety. Bacillus thuringiensis (BT) and B. anthracis Sterne (BA) spores were used to investigate the effectiveness of the electrochemical (EC) disinfection process. We tested the quaternary metal oxide (TiO2–Sb2O5–SnO2–RuO2) as the anode material in an EC cell for the inactivation of the spores. The presence of chloride ions at low concentrations was found to be critical for the effective inactivation of BT spores. Active chlorine was produced in-situ by anodic oxidation of chloride in the solutions. Local tap water used as a realistic test solution was found to contain average chloride concentrations of 1.2 mM. High concentrations of active chlorine were generated in the range of 0.35 to 0.5 mM (25 to 35 mg/L) to ensure that the high concentrations of spores were inactivated. We showed that the amount of active chlorine produced in the EC cell can be readily controlled by the operating conditions, including potential, flow rate and chloride content. Scanning electron images of the EC treated spores indicate damage to the outer membranes resulting in disruption and leakage of the spore contents. EC water disinfection processes using inexpensive electrode materials are a promising alternative as shown by inactivation of challenging biological threats such as Bacillus spores.