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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ag2W2O7 by Materials Project

Ag2W2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of W–O bond distances ranging from 1.78–2.22 Å. In the second W6+ site, W6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of W–O bond distances ranging from 1.76–2.34 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.21–2.85 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.33–2.68 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one W6+ and two Ag1+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one W6+ and one Ag1+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one W6+ and two Ag1+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two W6+ and one Ag1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two W6+ and one Ag1+ atom. In the sixth O2- site, O2- is bonded to three W6+ and one Ag1+ atom to form distorted edge-sharing OAgW3 tetrahedra. In the seventh O2- site, O2- is bonded in a linear geometry to two W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na3Ag3W2(OF)6 by Materials Project

Na3W2Ag3(OF)6 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 3-coordinate geometry to six equivalent F1- atoms. There are three shorter (2.34 Å) and three longer (2.56 Å) Na–F bond lengths. In the second Na1+ site, Na1+ is bonded to six equivalent F1- atoms to form NaF6 octahedra that share corners with six equivalent WO3F3 octahedra. The corner-sharing octahedral tilt angles are 36°. All Na–F bond lengths are 2.34 Å. W6+ is bonded to three equivalent O2- and three equivalent F1- atoms to form distorted WO3F3 octahedra that share corners with three equivalent NaF6 octahedra and corners with three equivalent AgO6 octahedra. The corner-sharing octahedra tilt angles range from 36–38°. All W–O bond lengths are 1.82 Å. All W–F bond lengths are 2.10 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to six equivalent O2- atoms to form AgO6 octahedra that share corners with six equivalent WO3F3 octahedra. The corner-sharing octahedral tilt angles are 38°. All Ag–O bond lengths are 2.49 Å. In the second Ag1+ site, Ag1+ is bonded in a distorted trigonal planar geometry to three equivalent O2- atoms. All Ag–O bond lengths are 2.30 Å. O2- is bonded in a 3-coordinate geometry to one W6+ and two Ag1+ atoms. F1- is bonded in a 4-coordinate geometry to three Na1+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnAg(PO3)3 by Materials Project

ZnAg(PO3)3 crystallizes in the orthorhombic Pcca space group. The structure is three-dimensional. Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.38–2.77 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to six O2- atoms to form ZnO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Zn–O bond distances ranging from 2.09–2.15 Å. In the second Zn2+ site, Zn2+ is bonded to six O2- atoms to form ZnO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Zn–O bond distances ranging from 2.05–2.19 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent ZnO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent ZnO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two ZnO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 45–46°. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent P5+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Zn2+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgCNO by Materials Project

AgNCO crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ag1+ is bonded to two equivalent C4+ and four equivalent O2- atoms to form a mixture of distorted face, edge, and corner-sharing AgC2O4 octahedra. The corner-sharing octahedral tilt angles are 57°. Both Ag–C bond lengths are 2.14 Å. All Ag–O bond lengths are 3.08 Å. C4+ is bonded in a 3-coordinate geometry to two equivalent Ag1+ and one N3- atom. The C–N bond length is 1.19 Å. N3- is bonded in a linear geometry to one C4+ and one O2- atom. The N–O bond length is 1.23 Å. O2- is bonded in a distorted single-bond geometry to four equivalent Ag1+ and one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgPb4ClO4 by Materials Project

AgPb4O4Cl crystallizes in the tetragonal P4/n space group. The structure is two-dimensional and consists of one AgPb4O4Cl sheet oriented in the (0, 0, 1) direction. Ag1+ is bonded in a 5-coordinate geometry to four equivalent O2- and one Cl1- atom. All Ag–O bond lengths are 2.52 Å. The Ag–Cl bond length is 2.56 Å. Pb2+ is bonded in a 3-coordinate geometry to three equivalent O2- atoms. There are a spread of Pb–O bond distances ranging from 2.26–2.30 Å. O2- is bonded to one Ag1+ and three equivalent Pb2+ atoms to form a mixture of edge and corner-sharing OAgPb3 trigonal pyramids. Cl1- is bonded in a distorted single-bond geometry to one Ag1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on V4(AgO4)3 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoAg(PO3)3 by Materials Project

CoAg(PO3)3 crystallizes in the orthorhombic Pcca space group. The structure is three-dimensional. there are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Co–O bond distances ranging from 2.06–2.16 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Co–O bond distances ranging from 2.08–2.14 Å. Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.38–2.77 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent P5+ atoms. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to one Co2+, one Ag1+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YbAg(MoO4)2 by Materials Project

YbAg(MoO4)2 is Zircon-derived structured and crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. Yb3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.43 Å) and four longer (2.44 Å) Yb–O bond lengths. There are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.81 Å. In the second Mo6+ site, Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.81 Å. Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.47 Å) and four longer (2.49 Å) Ag–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Yb3+, one Mo6+, and one Ag1+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Yb3+, one Mo6+, and one Ag1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Density Functional Theory Investigation of Oxidation Intermediates on Gold and Gold–Silver Surfaces

Gold and gold-silver alloys can be active and selective oxidation catalysts. Previous work has suggested that O 2 dissociation occurs at bimetallic step sites on gold-silver alloys, but the site responsible for the rest of the reaction steps has not been studied. As a first step in gaining insight into this issue, in this work we investigated the adsorption of oxygen and other oxidation intermediates on the (111) and (211) facets of gold-silver alloys using density functional theory. Oxygen and silver coverage effects were analyzed, and different model structures were compared. We also examined the energy barriers for the diffusion of atomic oxygen to gain insight into O migration and spillover. On (111) surfaces, O adsorption is much stronger at low O coverage (less than 0.22 ML), while on (211) surfaces O is strongly bound at both high and low O coverage. O diffusion across the step is faster than diffusion along the step. Ag stabilizes O, both when directly bound to it and when in an adjacent site. Ag also reduces repulsive O-O interactions at low O coverage. Our calculated reaction barriers for O-assisted CH 3 O dehydrogenation suggest that reaction is faster on steps than on terraces. Overall, our findings suggest that spillover of O from Ag-rich steps to Au-rich terraces does not occur, and that oxidation reactions on gold-silver alloys occurs on step sites. More specifically, oxidation likely occurs either on Ag-rich step sites or on Au-rich step sites that are adjacent to Ag-rich step sites.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

The effect of elastic strains on the adsorption energy of H, O, and OH in transition metals

The influence of elastic strains on the adsorption of H, O, and OH on the (111) surfaces of 8 fcc (Ni, Cu, Pd, Ag, Pt, Au, Rh, Ir) and on the (0001) surfaces of 3 hcp (Co, Zn, Cd) transition metals was analyzed by means of density functional theory calculations. To this end, surface slabs were subjected to different strain states (uniaxial, biaxial, shear, and a combination of them) up to strains dictated by the mechanical stability limits indicated by phonon calculations. It was found that the adsorption energy followed the predictions of the d-band theory but – surprisingly – the variations in the adsorption energy only depended on the area of the adsorption hole and not on the particular elastic strain tensor applied to achieve this area. The analysis of the electronic structure showed that the applied strains did not modify the shape of the Projected Density of States (PDOS) of the d-orbitals of the transition metals but only led to a shift in the energy levels. Moreover, the presence of the adsorbates on the surfaces led to negligible changes in the PDOS. Thus, the adsorption energies were a function of the Fermi energy which in turn was associated with the change of the area of the adsorption through a general linear law that was valid for all metals. Furthermore, the information in this paper allows the immediate and accurate estimation of the effect of any elastic strain on the adsorption energies of H, O, and OH in 11 transition metals with more than half-filled d-orbitals.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1994

Effects of silver ions (Ag+) on contractile ring function and microtubule dynamics during first cleavage in Ilyanassa obsoleta

The terminal phase of cell division involves tight constriction of the cleavage furrow contractile ring, stabilization/elongation of the intercellular bridge, and final separation of the daughter cells. At first cleavage, the fertilized eggs of the mollusk, Ilyanassa obsoleta, form two contractile rings at right angles to each other in the same cytoplasm that constrict to tight necks and partition the egg into a trefoil shape. The cleavage furrow contractile ring (CF) normally constricts around many midbody microtubules (MTs) and results in cleavage; the polar lobe constriction contractile ring (PLC) normally constricts around very few MTs and subsequently relaxes without cleavage. In the presence of Ag+ ions, the PLC 1) begins MT-dependent rapid constriction sooner than controls, 2) encircles more MTs than control egg PLCs, 3) elongates much more than control PLCs, and 4) remains tightly constricted and effectively cleaves the polar lobe from the egg. If Ag(+)-incubated eggs are returned to normal seawater at trefoil, tubulin fluorescence disappears from the PLC neck and the neck relaxes. If nocodazole, a drug that depolymerizes MTs, is added to Ag(+)-incubated eggs during early PLC constriction, the PLC is not stabilized and eventually relaxes. However, if nocodazole is added to Ag(+)-incubated eggs at trefoil, tubulin fluorescence disappears from the PLC neck but the neck remains constricted. These results suggest that Ag+ accelerates and gradually stabilizes the PLC constriction by a mechanism that is initially MT-dependent, but that progressively becomes MT-independent.

Non-NASA Center↗
NASA NTRS2016

Solar Powered CO.Sub.2 Conversion

Methods and devices for reducing CO.sub.2 to produce hydrocarbons are disclosed. A device comprises a photoanode capable of splitting H.sub.2O into electrons, protons, and oxygen; an electrochemical cell cathode comprising an electro-catalyst capable of reducing CO.sub.2; H.sub.2O in contact with the surface of the photoanode; CO.sub.2 in contact with the surface of the cathode; and a proton-conducting medium positioned between the photoanode and the cathode. Electrical charges associated with the protons and the electrons move from the photoanode to the cathode, driven in part by a chemical potential difference sufficient to drive the electrochemical reduction of CO.sub.2 at the cathode. A light beam is the sole source of energy used to drive chemical reactions. The photoanode can comprise TiO.sub.2 nanowires or nanotubes, and can also include WO.sub.3 nanowires or nanotubes, quantum dots of CdS or PbS, and Ag or Au nanostructures. The cathode can comprise a conductive gas diffusion layer with nanostructures of an electro-catalyst such as Cu or Co.

Chen, Bin↗
DOE OSTI2020

Materials Data on Ga12Ag2Te19 by Materials Project

Ag2Ga12Te19 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to three Te2- atoms. There are a spread of Ag–Te bond distances ranging from 2.77–3.03 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four Te2- atoms. There are a spread of Ag–Te bond distances ranging from 2.85–3.25 Å. There are twelve inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.59–2.78 Å. In the second Ga3+ site, Ga3+ is bonded in a trigonal planar geometry to three Te2- atoms. There are a spread of Ga–Te bond distances ranging from 2.51–2.63 Å. In the third Ga3+ site, Ga3+ is bonded to four Te2- atoms to form corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.64–2.76 Å. In the fourth Ga3+ site, Ga3+ is bonded in a trigonal planar geometry to three Te2- atoms. There are a spread of Ga–Te bond distances ranging from 2.57–2.62 Å. In the fifth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.62–2.83 Å. In the sixth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.61–2.72 Å. In the seventh Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.60–2.74 Å. In the eighth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.62–2.77 Å. In the ninth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.66–2.75 Å. In the tenth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.67–2.79 Å. In the eleventh Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.62–2.74 Å. In the twelfth Ga3+ site, Ga3+ is bonded to four Te2- atoms to form a mixture of edge and corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.58–2.78 Å. There are nineteen inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in an L-shaped geometry to two Ga3+ atoms. In the second Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ga3+ atoms. In the third Te2- site, Te2- is bonded in a 3-coordinate geometry to one Ag1+ and two Ga3+ atoms. In the fourth Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ga3+ atoms. In the fifth Te2- site, Te2- is bonded in an L-shaped geometry to two Ga3+ atoms. In the sixth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ga3+ atoms. In the seventh Te2- site, Te2- is bonded in an L-shaped geometry to two Ga3+ atoms. In the eighth Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ga3+ atoms. In the ninth Te2- site, Te2- is bonded in an L-shaped geometry to two Ga3+ atoms. In the tenth Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and two Ga3+ atoms. In the eleventh Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ga3+ atoms. In the twelfth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ga3+ atoms. In the thirteenth Te2- site, Te2- is bonded in a 3-coordinate geometry to one Ag1+ and two Ga3+ atoms. In the fourteenth Te2- site, Te2- is bonded in a 2-coordinate geometry to two Ag1+ and two Ga3+ atoms. In the fifteenth Te2- site, Te2- is bonded in a 3-coordinate geometry to one Ag1+ and two Ga3+ atoms. In the sixteenth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ga3+ atoms. In the seventeenth Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ga3+ atoms. In the eighteenth Te2- site, Te2- is bonded in a 3-coordinate geometry to one Ag1+ and two Ga3+ atoms. In the nineteenth Te2- site, Te2- is bonded in an L-shaped geometry to two Ga3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Highly efficient, rapid, and concurrent removal of toxic heavy metals by the novel 2D hybrid LDH–[Sn 2 S 6 ]

According to a United Nations report, by 2050 nearly six billion people worldwide will suffer from clean water scarcity. This is mostly because of the exponential proliferation of world population, urbanization, industrialization, and water pollution. Heavy metals are common water pollutants that can pose grave public health consequences. Existing water purification systems are lack of materials that have the potential for quick, simultaneous, efficient, and cost-efficient removal of numerous toxic metals from wastewater. Here, in this work, we report the design and synthesis of an economically viable Layered Double Hydroxides - Stannic Sulfide, LDH–[Sn 2 S 6 ] that exhibits a rapid, efficient, selective, and concurrent removal of Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ from parts per million (ppm) level to below 5 parts per billion (ppb) satisfying World Health Organization’s (WHO) safe drinking water limit. Moreover, LDH–[Sn 2 S 6 ] shows exceptionally high removal efficiencies of the above metals in acidic, neutral, and basic conditions. LDH–[Sn 2 S 6 ] also demonstrates enormous sorption capacities of 378, 978, 332, 579, and 666 mg/g for Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ , respectively. Remarkably, LDH–[Sn 2 S 6 ] displays extraordinary tolerance to the concentrations of Na + , Ca 2+ , Mg 2+ , Cl - , CO 3 2– , NO 3 – ,and SO 4 2- , and other constituents in tap and river water, it efficiently sequestrates Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ from ppm to safe drinking water levels in minutes. LDH–[Sn 2 S 6 ] shows pseudo-second-order sorption kinetics suggesting chemisorption adsorption mechanism involving M–S bonding. Altogether, the regeneratable LDH–[Sn 2 S 6 ] becomes an exceptional material that shows ultrahigh removal, unprecedented selectivity, rapid adsorption kinetics, wide pH stability, and a massive adsorption capacity. The integration of these features places LDH–[Sn 2 S 6 ] at the top of all adsorbents known to date and thus could be used for wastewater purifications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Zn3Ag2(GeO4)3 by Materials Project

Ag2Zn3(GeO4)3 crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Ag3+ is bonded to six equivalent O2- atoms to form AgO6 octahedra that share corners with six equivalent GeO4 tetrahedra. All Ag–O bond lengths are 2.18 Å. Zn2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.31 Å) and four longer (2.38 Å) Zn–O bond lengths. Ge4+ is bonded to four equivalent O2- atoms to form GeO4 tetrahedra that share corners with four equivalent AgO6 octahedra. The corner-sharing octahedral tilt angles are 60°. All Ge–O bond lengths are 1.80 Å. O2- is bonded in a 4-coordinate geometry to one Ag3+, two equivalent Zn2+, and one Ge4+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1990

Effects of grain size and grain boundary on critical current density of high T(sub c) superconducting oxides

By means of adding impurity elements in high T sub c oxides, the effects were studied of grain size and grain boundary on the critical current density of the following systems: YBa2Cu3O(7-y) and Bi-Pr-Sr-Ca-Cu-O. In order to only change the microstructure instead of the superconductivity of the grains in the samples, the impurity elements were added into the systems in terms of the methods like this: (1) substituting Y with the lanthanide except Pr, Ce, and Tb in YBa2Cu3O(7-y) system to finning down grains in the samples, therefore, the effect can be investigated of the grain size on the critical current density of 1:2:3 compounds; (2) mixing the high T sub c oxides with the metal elements, such as Ag, according to the composition of (high T sub c oxide)1-xAgx to metallize the grain boundaries in the samples, studying the effect of the electric conductivity of the grain boundaries on the critical current density; (3) adding SiO2, PbO2, and SnO2 into the high T sub c oxide to form impurity phases in the grain boundaries, trying to find out the effects of the impurity phases or metalloid grain boundaries on the critical current density of the high T sub c superconductors. The experimental results indicate that in the case of of the presence of the metalloid grain boundaries finning down grains fails to enhance the j sub c, but restrains it strongly, the granular high T sub c superconductors with the small size grains coupled weakly is always the low j sub c system.

Zhao, Y.↗
DOE OSTI2021

Iodine Vapor Reactions with Pure Metal Wires at Temperatures of 100–139 °C in Air

In this work, I 2(g) reactions with 11 metal wires (i.e., Al, Ag, Cu, In, Mo, Nb, Ni, Pd, Pt, Sn, Ta) were evaluated at three temperatures (i.e., 100 ± 3°C, 123 ± 4°C, 139 ± 5°C) with exposure times of 24 hours at each temperature. Over these temperatures, some of the metals showed increased mass gain with higher temperatures (i.e., In, Ag, Cu), Sn showed decreased iodine capture at increased temperatures, and most metals (i.e., Mo, Nb, Ni, Pd, Pt, and Ta) showed little to no mass gain at all temperatures. Silver mordenite (AgZ) was used as a standard during these studies and showed a consistent mass gain (m% I ) of 10.6 → 12.8% over this temperature range. The values of mass of iodine captured per mass of starting metal (g g -1 ) ranged widely across the study with the highest values achieved for (in descending order) Sn-T 100°C (4.37), In-T 139°C (3.34), Sn-T 123°C (1.98), In-T 123°C (1.57), Ag-T 139°C (1.19), In-T 100°C (0.97), and Cu-T 139°C (0.71). In some cases, the metal-iodide complex was not stable at the experimental temperature and it was clear some volatility had occurred during the experiment based on discoloration in the vials. These results show that some metals can have extensive reactions with I 2(g) without showing metal-iodide preferences over metal-oxide formation based on thermodynamic predictions. It is possible that materials such as these could be implemented near nuclear facilities to getter I 2(g) in the event of a nuclear accident.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on TlAgS by Materials Project

AgTlS crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ag1+ is bonded in a 3-coordinate geometry to six equivalent Tl1+ and three equivalent S2- atoms. There are a spread of Ag–Tl bond distances ranging from 3.25–3.56 Å. There are one shorter (2.58 Å) and two longer (2.61 Å) Ag–S bond lengths. Tl1+ is bonded in a 2-coordinate geometry to six equivalent Ag1+, two equivalent Tl1+, and six equivalent S2- atoms. Both Tl–Tl bond lengths are 3.55 Å. There are a spread of Tl–S bond distances ranging from 3.12–3.64 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Ag1+ and six equivalent Tl1+ atoms.

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