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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records

Metal–Carbodithioate-Based 3D Semiconducting Metal–Organic Framework: Porous Optoelectronic Material for Energy Conversion

Solar energy conversion requires the working compositions to generate photoinduced charges with high potential and the ability to deliver charges to the catalytic sites and/or external electrode. These two properties are typically at odds with each other and call for new molecular materials with sufficient conjugation to improve charge conductivity but not as much conjugation as to overly compromise the optical band gap. In this work, we developed a semiconducting metal-organic framework (MOF) prepared explicitly through metal-carbodithioate"(-CS 2 ) n M" linkage chemistry, entailing augmented metal-linker electronic communication. The stronger ligand field and higher covalent character of metal-carbodithioate linkages-when combined with spirofluorene-derived organic struts and nickel-(II) ion-based nodes-provided a stable, semiconducting 3D-porous MOF, Spiro-CS 2 Ni. This MOF lacks long-range ordering and is defined by a flexible structure with non-aggregated building units, as suggested by reverse Monte Carlo simulations of the pair distribution function obtained from total scattering experiments. The solvent-removed "closed pore"material recorded a Brunauer-Emmett-Teller area of similar to 400m 2 /g, where the "open pore" form possesses90 wt % solvent-accessible porosity. Electrochemical measurements suggest that Spiro-CS 2 Ni possesses a band gap of 1.57 eV(sigma = 10 -7 S/cm at -1.3 V bias potential),which can be further improved by manipulating the d-electron configuration through an axial coordination (ligand/substrate), the latter of which indicates usefulness as an electrocatalyst and/or a photoelectrocatalyst(upon substrate binding). Transient-absorption spectroscopy reveals a long-lived photo-generated charge-transfer state (τ CR = 6.5 mu s) capable of chemical transformation under a biased voltage. Spiro-CS 2 Ni can endure a compelling range of pH(1-12 for weeks) and hours of electrochemical and photoelectrochemical conditions in the presence of water and organic acids. We believe this work provides crucial design principles for low-density, porous,light-energy-conversion materials.

36 MATERIALS SCIENCE↗

Influence of Rare-Earth Ion Radius on Metal–Metal Charge Transfer in Trinuclear Mixed-Valent Complexes

We report the synthesis and characterization of a highly conjugated bisferrocenyl pyrrolediimine ligand, Fc 2 PyrDIH (1), and its trinuclear complexes with rare earth ions—(Fc 2 PyrDI)M(N(TMS) 2 ) 2 (2-M, M = Sc, Y, Lu, La). Crystal structures, NMR spectra, and UV/Vis-NIR data are presented. The latter are in good agreement with DFT calculations, illuminating the impact of the rare earth ionic radius on NIR charge transfer excitations. For [2-Sc] + , the charge transfer is at 11500 cm -1 , while for [2-Y] + only a d-d transition at 8000 cm -1 is observed. Lu has an ionic radius in between Sc and Y, and the [2-Lu] + complex exhibits both transitions. From TDDFT analysis we assign the 11500 cm -1 transition as a mixture of MLCT and MMCT, rather than pure metal-to-metal CT, because it has significant ligand character. Typically, the ferrocenes have high rotational freedom in bis-ferrocenyl mixed valent complexes. However, in the present (Fc 2 PyrDI)M(N(TMS) 2 ) 2 complexes, ligand-ligand repulsions lock the rotational freedom, so that rare earth ionic radius-dependent geometric differences increasingly influence orbital overlap as the ionic radius falls. The Marcus-Hush coupling constant HAB trends as: [2-Sc] + >[2-Lu] + >[2-Y] +

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Metal coated articles comprising a refractory metal region and a platinum-group metal region, and related methods

A metal coated article includes a platinum-group metal region adjacent a refractory metal region, which is adjacent a substrate comprising an inorganic material. A refractory metal carbide layer is adjacent the substrate and the refractory metal layer is adjacent the refractory metal carbide layer. The platinum-group metal region comprises a refractory metal/platinum-group metal layer and a platinum-group metal layer. Related methods are also disclosed.

Tripathy, Prabhat K.↗

Method embodiments for making lanthanide metal complexes from lanthanide metal oxides and separating the same from heavy lanthanide metal oxides, actinide oxides, and non-lanthanide rare earth element oxides

The present disclosure is directed to method embodiments for making anhydrous lanthanide halide complexes. At least some embodiments comprise making a lanthanide halide complex by reacting a lanthanide metal oxide with an oxygen scavenger and catalyst in the presence of a donor solvent. The method is selective toward light lanthanide metal oxides and thus further provides a method for separating light lanthanide metal oxides from heavy lanthanide metal oxides, actinide oxides, and non-lanthanide rare earth element oxides.

Kiplinger, Jaqueline Loetsch↗

A study of adhesive bonding in metal–metal, metal–CFRP, and CFRP–CFRP material combinations under shear deformation: Fracture morphologies and damage mechanisms

Safe design of adhesive joining in multi-materials in engineered structures requires the accumulation of numerous experimental data on the failure behavior of various adhesively-bonded material combinations under different loading conditions. The deep understanding of mechanical performance, fracturing morphologies, and main damage mechanisms is also quintessential for accelerating the development of proper physics-based and multi-scale models for assisting the design. Towards this goal, this work presents a comprehensive characterization of the failure behavior of adhesively-bonded metal–metal, metal–CFRP, and CFRP–CFRP material combinations under global shear deformation via single lap shear testing. Thanks to a synergistic combination of measurement methods by using Digital Imaging Correlation (DIC) and 3D optical profilometry, adhesive features on the adherend after failure were quantified and the main progressive damage mechanisms were identified. The characterization performed in this work provides quantitative data that contributes to a better understanding of shear failure in adhesive bonding across different bi-material combinations. Finally, the obtained results have practical implications, including the potential to enhance adhesive bonding design, identify failure causes in adhesive joints, and develop or validate computational models capable of capturing the observed behavior in various adhesively-bonded materials under global shear deformation.

36 MATERIALS SCIENCE↗

Metallic Cu Surface Enables Reversible Na Metal Anodes and Stabilizes Anode-Free Sodium Metal Batteries

Anode free Na metal batteries are promising for future energy storage because they not only provide the highest energy densities but also eliminate the need of handling hazardous Na metals during battery manufacturing. However, they suffer from much faster degradation due to strong sensitivities even to trace levels of side reactions. In view of the crucial roles of surface chemistry on modulating electrochemical plating, this work systematically investigated a series of Cu surfaces for Na plating and stripping in the 1.0 M NaPF 6 diglyme electrolyte. Our results suggest that Na plating and stripping on pure Cu surface without Cu oxide species exhibits much better reversibility and smaller overpotentials across a wide range of current densities, especially for the first plating/stripping cycle. The high performance includes consistently higher than 99.8% Faradaic efficiencies, much more stable interfacial resistance, and negligible formation of mossy Na after 500 cycles. This improved performance can be explained based on the stronger Na-Cu affinity compared with the Na-CuO affinity. Anode-free Na metal batteries equipped with high-capacity sodium vanadium phosphate cathodes and pure Cu current collector exhibited at least 70% capacity retention for 100 cycles.

Electrochemistry↗

Hydrated Metal and Metal-Nitrate Complexes in Water: Full Lanthanide(III) Series plus Miscellaneous Metal Ions

This is a dataset of hydrated metal complexes and metal–nitrate hydrated complexes intended for public use, reproducibility, and downstream structural analysis. A key feature is coverage across the full lanthanide(III) series (La–Lu), enabling systematic comparisons of coordination motifs and bonding trends across the entire lanthanide sequence. In addition to the lanthanides, the dataset also includes other metal ions such as UO2(VI), Fe(II), and Fe(III). The dataset provides optimized geometries for hydrated and nitrate-containing hydrated complexes, together with representative ab initio molecular dynamics (AIMD) trajectories saved in standard XYZ formats. The accompanying NWChem input decks enable reproduction of the reported calculations and provide a starting point for extending the simulations to related coordination environments. Computationally, DFT calculations employ the B3LYP functional with DFT-D3BJ dispersion corrections and a COSMO continuum solvent model (dielectric constant 78.4) to represent solvation beyond the explicitly treated first hydration shell. AIMD simulations are performed with the NWChem qmd module at 298 K, integrating nuclear motion with the velocity-Verlet algorithm and controlling temperature using a Nosé–Hoover thermostat. Trajectories are approximately 4.8 ps in length and are used primarily to assess short-time stability of candidate coordination motifs, including (for lanthanides) differences between 8- versus 9-water coordination and comparisons between nitrate-bound and nitrate-free hydrated complexes.

Dinpajooh, Mohammadhasan [Pacific Northwest Nation↗

Short-Term Inhibition and Long-Term Enhancement of Irreversible Trace Metal Binding to Goethite in Multi-Metal Systems

Iron (oxyhydr)oxide minerals are important sorbents of trace metals in aquatic environments. Adsorption–desorption hysteresis has been documented for trace metals after aging, suggesting that they become incorporated over time. We previously found that ion size controls the extent of irreversible metal binding of single metals to goethite. In this study, we evaluate how the presence of multiple metals influences irreversible binding. Mixed Ni–Zn and Ni–Cd solutions were aged with goethite at pH 7 for 2 days, 30 days, and 60 days, after which isotope exchange experiments were performed to assess the lability of the adsorbed metal pools. After 2 days of aging, Ni and Cd in mixed-metal systems were more labile than in single-metal systems, indicating that competitive adsorption may partially block irreversible binding on short time scales. After 60 days, all three metals had larger irreversibly bound fractions than in single-metal systems. X-ray absorption near-edge structure (XANES) spectroscopy indicates that irreversibly bound fractions correlate with incorporation into goethite. This study demonstrates that pools of coadsorbed metals are bioaccessible on a time scale of minutes. Cooperative effects promote the structural sequestration of even large trace metals, causing reactive transport models to likely overpredict metal mobility. Long-term metal entrapment processes hinder micronutrient availability, impact contaminant sequestration and critical mineral recovery, and yield complex pathways through which metal solubilization may be enhanced or hindered during redox cycling.

58 GEOSCIENCES↗

Effects of Metal and Metal Ion on Biomethane Productivity during Anaerobic Digestion of Dairy Manure

To overcome major limiting factors of microbial processes in anaerobic digestion (AD), metal and metal ions have been extensively studied. However, there is confusion about the effects of metals and metal ions on biomethane productivity in previous research. In this study, Zn and Zn 2+ were selected as representatives of metals and metal ions, respectively, to investigate the effects on biomethane productivity. After the metals and metal ions at different concentrations were added to the batch AD experiments under the same mesophilic conditions, a Zn dose of 1 g/L and a Zn 2+ dose of 4 mg/L were found to cause the highest biomethane production, respectively. The results indicate that metal (Zn) and metal ion (Zn 2+ ) have different mechanisms to improve AD performance. There may be two possible explanations. To act as conductive materials in interspecies electron transfer (IET), relatively high doses of metals (e.g., 1 g/L of Zn, 10 g/L of Fe) are needed to bridge the electron transfer from syntrophic bacteria to methanogenic archaea in the AD process. As essential mineral nutrients, the AD system requires relatively low doses of metal ions (e.g., 4 mg/L of Zn 2+ , 5 mg/L of Fe 2+ ) to supplement the component of various enzymes that catalyze anaerobic reactions and transformations. This research will provide clear insight for selecting appropriate amounts of metals or metal ions to enhance biomethane productivity for industrial AD processes.

09 BIOMASS FUELS↗

X-ray Spectroscopy Characterization of Electronic Structure and Metal–Metal Bonding in Dicobalt Complexes

Developing multimetallic complexes with tunable metal–metal interactions has long been a target of synthetic inorganic chemistry efforts due to the unique properties that such compounds can exhibit. However, understanding relationships between metal–metal bonding and chemical properties is challenging due to system-dependent factors that influence metal–metal and metal–ligand interactions, including ligand identity, coordination geometry, and metal–metal distance. In this work, we apply X-ray absorption and emission spectroscopy and quantum chemical calculations to describe electronic structure and bonding in a series of dicobalt complexes. The compounds with silane ligands and pseudo-octahedral coordination geometry exhibit Co–Co σ and multicentered bonding character, which we characterize from both the occupied and vacant perspectives via their contributions to the Co X-ray emission and absorption spectra, respectively. In contrast, the dicobalt complexes with a pseudotetrahedral coordination environment do not exhibit Co–Co bonding due to symmetry constraints on orbital overlap. We extend these insights to the theoretical evaluation of related dicobalt complexes to explain how ligand coordination and symmetry dictate the presence or absence of a Co–Co bond. In conclusion, this work highlights how fundamental insights into electronic structure and bonding through X-ray spectroscopy uncover important factors governing metal–metal interactions and guide the rational design of multimetallic complexes with tunable metal–metal bonds.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Rechargeable metal-metal alkaline batteries: Recent advances, current issues and future research strategies

Over the past few decades, remarkable advancement has been attained in the field of rechargeable metal–metal alkaline batteries (RABs). In terms of safety, energy density, charge-discharge capacity, and long-term storage capability, metal-metal RABs (e.g., Ni–Zn, Ni–Fe, Ni–Bi, Ni–MH, Ag–Zn, Co–Zn, Cu–Zn, and Bi–Zn systems) are contemplated as the promising energy storage devices for the applications in electric vehicles (EVs), hybrid EVs, grid-scale energy storage, as well as various implantable and wearable electronic devices. Especially, Ni-MH batteries become competitive with Li-ion batteries for EVs and hybrid EVs applications due to their high tolerance against mechanical abuse, stability under wide temperature ranges, and considerable charge/discharge capacity. Meanwhile, earlier works reviewed only specific topics, so, as a rapidly growing research topic, providing a deep understanding on metal–metal RABs is timely and worthwhile. So here, in this work, we discuss the electrochemistry of all metal-metal RABs, then full cell designing with their performance will be discussed thoroughly. Further, issues associated with the existing metal–metal RABs and corresponding improvement approaches will be provided for future advances in high-performance and reliable metal-metal RABs.

25 ENERGY STORAGE↗

Polarized metal–metal multiple bonding and reactivity of phosphinoamide-bridged heterobimetallic group IV/cobalt compounds

Heterobimetallic complexes are studied for their ability to mimic biological systems as well as active sites in heterogeneous catalysts. While specific interest in early/late heterobimetallic systems has fluctuated, they serve as important models to fundamentally understand metal–metal bonding. Specifically, the polarized metal–metal multiple bonds formed in highly reduced early/late heterobimetallic complexes exemplify how each metal modulates the electronic environment and reactivity of the complex as a whole. In this Perspective, we chronicle the development of phosphinoamide-supported group IV/cobalt heterobimetallic complexes. This combination of metals allows access to a low valent Co −I center, which performs a rich variety of bond activation reactions when coupled with the pendent Lewis acidic metal center. Conversely, the low valent late transition metal is also observed to act as an electron reservoir, allowing for redox processes to occur at the d 0 group IV metal site. Most of the bond activation reactions carried out by phosphinoamide-bridged M/Co −I (M = Ti, Zr, Hf) complexes are facilitated by cleavage of metal–metal multiple bonds, which serve as readily accessible electron reservoirs. Comparative studies in which both the number of buttressing ligands as well as the identity of the early metal were varied to give a library of heterobimetallic complexes are summarized, providing a thorough understanding of the reactivity of M/Co −I heterobimetallic systems

Hunter, Nathanael H.↗

Influence of aluminum incorporation and aqueous conditions on metal ion release of high-Ni transition metal oxide nanomaterials

Developing a materials perspective of how to control the degradation and negative impact of complex metal oxides requires an integrated understanding of how these nanomaterials transform in the environment and interact with biological systems. Doping with aluminum is known to stabilize oxide materials, but has not been assessed cohesively from synthesis to environmental fate and biological impact. In the present study, the influence of aluminum doping on metal ion release from transition metal oxides was investigated by comparing aqueous transformations of lithium nickel cobalt aluminum oxide (LiNi 0.82 Co 0.15 Al 0.03 O 2 ; NCA) and lithium nickel cobalt oxide (LiNi 0.80 Co 0.20 O 2 ; NC) nanoparticles and by calculating the energetics of metal release using a density functional theory (DFT) and thermodynamics method. Two model environmental organisms were used to assess biological impact, and metal ion release was compared for NCA and NC nanoparticles incubated in their respective growth media: moderately hard reconstituted water (MHRW) for the freshwater invertebrate Daphnia magna (D. magna) and minimal growth medium for the Gram-negative bacterium Shewanella oneidensis MR-1 (S. oneidensis). Further, the amount of metal ions released was reduced for NCA compared to NC in MHRW, which correlated to changes in the modeled energetics of release upon Al substitution in the lattice. In minimal medium, metal ion release was approximately an order of magnitude higher compared to MHRW and was similar to the stoichiometry of the bulk nanoparticles for both NCA and NC. Interpretation of the release profiles and modeling indicated that the increase in total metal ion release and the reduced influence of Al doping arises from lactate complexation of metal ions in solution. The relative biological impacts of NC and NCA exposure for both S. oneidensis and D. magna were consistent with the metal release trends observed for minimal medium and MHRW, respectively. Together, these results demonstrate how a combined experimental and computational approach provides valuable insight into the aqueous transformations and biological impacts of complex metal oxide nanoparticles.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Quantifying metal-binding specificity of Cc NikZ-II from Clostridium carboxidivorans in the presence of competing metal ions

Many proteins bind transition metal ions as cofactors to carry out their biological functions. Despite binding affinities for divalent transition metal ions being predominantly dictated by the Irving-Williams series for wild-type proteins, in vivo metal ion binding specificity is ensured by intracellular mechanisms that regulate free metal ion concentrations. However, a growing area of biotechnology research considers the use of metal-binding proteins in vitro to purify specific metal ions from wastewater, where specificity is dictated by the protein's metal binding affinities. A goal of metalloprotein engineering is to modulate these affinities to improve a protein's specificity towards a particular metal; however, the quantitative relationship between the affinities and the equilibrium metal-bound protein fractions depends on the underlying binding mechanisms. Here we demonstrate a high-throughput intrinsic tryptophan fluorescence quenching method to validate binding models in multi-metal solutions for CcNikZ-II, a nickel-binding protein from Clostridium carboxidivorans. Using our validated models, we quantify the relationship between binding affinity and specificity in different classes of metal-binding models for CcNikZ-II. In conclusion, we further illustrate the potential relevance of data-informed models to predicting engineering targets for improved specificity.

59 BASIC BIOLOGICAL SCIENCES↗

Photometric metallicity for 694 233 Galactic giant stars from Gaia DR3 synthetic Strömgren photometry: Metallicity distribution functions of halo substructures

We used two previous calibrations and the standardised synthetic photometry in the v, b, and y Strömgren passbands from Gaia DR3 BP/RP spectra to obtain photometric metallicities for a selected sample of 694 233 old Galactic giant stars having |b|> 20.0° and parallax uncertainties lower than 10%. The zero point of both sets of photometric metallicities has been shifted to ensure an optimal match with the spectroscopic [Fe/H] values for 44 785 stars in common with APOGEE DR17, focusing on the metallicity range where they provide the highest accuracy. The metallicities derived in this way from one calibration display a typical accuracy of ≲0.1 dex and 1σ precision ≲0.2 dex in the range -2.2 ≲ [Fe/H] ≲ - 0.4, while they show a systematic trend with [Fe/H] at higher metallicity, beyond the applicability range of the relation. Those derived from the other calibration display, in general, reduced precision, and lower accuracy in the metal-poor regime, but have a median accuracy < 0.05 dex for [Fe/H] ≥ - 0.8. These results are confirmed and, consequently, the metallicities are validated, by comparison with large sets of spectroscopic metallicities from various surveys. The newly obtained metallicities are used to derive metallicity distributions for several previously identified substructures in the Galactic halo with an unprecedented number of stars. The catalogue including the two sets of metallicities and the associated uncertainties is made publicly available.

79 ASTRONOMY AND ASTROPHYSICS↗

Superior metal storage behavior of Zn-containing porous carbon nanostructures for Na and Li metal batteries

Na and Li metals are ideal anodes for high-energy rechargeable batteries. However, their poor coulombic efficiency and the associated safety issues due to dendritic metal deposition and large volume changes during metallic plating/stripping are the major causes that persistently hinder their practical energy-storage applications. Herein, Zn-containing carbon nanostructures derived from typical zeolitic imidazolate framework-8 (ZIF-8) are proposed as advanced metal anode materials for both Na and Li metal batteries. In this study; the three-dimensional interconnected porous surfaces confine metallic Na and Li within the nanostructures, filling the carbon scaffold, and covering the electrode surface to form stable solid electrolyte interphases. Based on the metal nucleation and growth results obtained through various electrochemical tests, Zn incorporation and pore morphology have been revealed to be the key factors that regulate the metal nucleation and metallic plating/stripping during cycling. Thus, the incorporation of Zn in the closed pores of a carbon nanostructure improves the cycle performance, even in carbonate electrolytes, and produces stable Na and Li metallic anodes for next-generation rechargeable batteries.

25 ENERGY STORAGE↗

Metal Complex Inks for Low-Cost Photovoltaic Material Metallization

The aim of the project titled “Metal Complex Inks for Low-Cost Photovoltaic Material Metallization” was to develop new metal complex conductive inks and pastes for PV, invented and commercialized by Electroninks, Inc. (EI, Austin, TX USA, https://electroninks.com), the only global supplier and scaled-manufacturing company of these metal complex inks. These materials were developed in this work for photovoltaic applications to significantly lower the cost of metallization, improve the manufacturability, and greatly reduce metal usage, while maintaining or improving device efficiencies when compared to traditional nanoparticle-based inks. The new pastes will do so by: 1) lowering the finger resistivity and precious metals usage by printing much denser (and therefore thinner/less material) metal films than possible with traditional particle-based screen-printed pastes; 2) decreasing the firing temperature to help preserve passivation; and 3) enabling a path to move the TW-scale PV industry from Ag to other materials including Ni, Cu, and Ni/Cu alloy pastes while continuing to leverage capital investment and expertise in screen printing metallization.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗