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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Reduction of Chlorinated Ethenes by Ag- and Cu-Amended Green Rust

Chlorinated ethenes have been used extensively as solvents, degreasers, and dry-cleaning agents in a range of commercial and industrial applications. This has created a legacy of contaminated soils and groundwater, particularly with respect to perchloroethylene (PCE; a.k.a. tetrachloroethene—C 2 Cl 4 ), and trichloroethylene (TCE; a.k.a. trichloroethene—C 2 HCl 3 ), prompting the development of a wide array of treatment technologies for remediation of chlorinated ethene-contaminated environments. Green rusts are highly redox-active layered Fe(II)-Fe(III) hydroxides that have been shown to be facile reductants for a wide range of organic and inorganic pollutants. The reduction of chlorinated ethenes [vinyl chloride (VC); 1,1-dichloroethene(11DCE), cis-1,2-dichloroethene (c12DCE), trans-1,2-dichloroethene (t12DCE), TCE, and PCE] was examined in aqueous suspensions of green rust, alone as well as with the addition of Ag(I) (AgGR) or Cu(II) (CuGR). Green rust alone was ineffective as a reductant for the reductive dechlorination for all of the chlorinated ethenes. Near-complete removal of PCE was observed in the presence of AgGR, but all other chlorinated ethenes were essentially non-reactive. Partial removal of chlorinated ethenes was observed in the presence of CuGR, particularly 11DCE (34%), t12DCE (51%), and VC (66%). Significant differences were observed in the product distributions of chlorinated ethene reduction by AgGR and CuGR. The effectiveness of Ag(I)- and Cu(II)-amended green rusts for removal of chlorinated ethenes may be improved under different conditions (e.g., pH and interlayer anion) and warrants further investigation.

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

Materials Data on AgC4OF9 by Materials Project

AgCO(CF3)3 is Ammonia-derived structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of twelve fluoroform molecules and one AgCO cluster. In the AgCO cluster, there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to two O2- atoms. There are one shorter (2.25 Å) and one longer (2.34 Å) Ag–O bond lengths. In the second Ag1+ site, Ag1+ is bonded in a distorted linear geometry to two O2- atoms. There are one shorter (2.17 Å) and one longer (2.20 Å) Ag–O bond lengths. There are two inequivalent C+2.50+ sites. In the first C+2.50+ site, C+2.50+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.38 Å. In the second C+2.50+ site, C+2.50+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.39 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Ag1+ and one C+2.50+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Ag1+ and one C+2.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Evaluating the effect of ionomer chemical composition in silver-ionomer catalyst inks toward the oxygen evolution reaction by half-cell measurements and water electrolysis

The effect of anion exchange ionomer (AEI) chemistry on the kinetics of the oxygen evolution reaction (OER) was systematically studied in both half-cell and single-cell electrolysis experiments. OER was studied in 1 M K 2 CO 3 at 50°C using an array of ionomer-silver catalyst inks deposited on Ni foam. Different ionomer modifications were investigated to optimize the OER performance. The AEI used in this work features a block copolymer backbone of polychloromethylstyrene-b-polycyclooctene-b-polychloromethylstyrene which was functionalized with either benzyltrimethylammonium (TMA) or benzylmethylpiperidinium (MPRD) quaternary ammonium cations. Here, using an MPRD quaternary ammonium cation shifted the rate determining step at high overpotentials, ultimately providing enhanced performance. Increasing the catalyst ink dilution was also found to substantially improve mass activity and catalyst utilization (increase from 35 to 88 A g –1 Ag), likely by reducing the ionomer thickness and decreasing transport resistances. In the final ionomer modification, the Ni foam substrate was leveraged to partially hydrogenate the polycyclooctene midblock to be polyethylene-like at the Ni interface. A significant increase in the electrochemical surface area (Cdl increased from 8.8 to 20.8 mF cm –2 ) and performance (by 47 mA cm –2 or 29 A g –1 Ag) was observed with the incorporation of polyethylene. Kinetic results from half-cell experiments were validated via single-cell anion exchange membrane electrolysis experiments, where the optimized electrode displayed enhanced performance in both 1 M K 2 CO 3 and DI H 2 O.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Chiral Recognition: A Spin-Driven Process in Chiral Oligothiophene. A Chiral-Induced Spin Selectivity (CISS) Effect Manifestation

In this paper it is experimentally demonstrated that the electron-spin/molecular-handedness interaction plays a fundamental role in the chiral recognition process. This conclusion is inferred comparing current versus potential (I-V) curves recorded using chiral electrode surfaces, which are obtained via chemisorption of an enantiopure thiophene derivative: 3,3'-bibenzothiophene core functionalized with 2,2'-bithiophene wings (BT 2 T 4 ). The chiral recognition capability of these chiral-electrodes is probed via cyclic voltammetry measurements, where, Ag nanoparticles (AgNPs) capped with enantiopure (BT 2 T 4 ) (BT 2 T 4 )@AgNP) are used as the chiral redox probe. Then, the interface handedness is explored by recording spin-polarized (I-V) curves in spin-dependent electrochemistry (SDE) and magnetic-conductive atomic force microscopy (mc-AFM) experiments. The quality of the interfaces is thoroughly cross-checked using X-ray photoemission spectroscopy, Raman, electrodesorption measurements, which further substantiate the metal(electrode)-sulfur(thiophene) central role in the chemisorption process. Spin-polarization values of about 15% and 30% are obtained in the case of SDE and mc-AFM experiments, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgBi(IO3)4 by Materials Project

AgBi(IO3)4 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.38–2.87 Å. In the second Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ag–O bond distances ranging from 2.38–2.97 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.38–2.55 Å. In the second Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.40–2.61 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.86 Å. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one I5+ atom. The O–I bond length is 1.84 Å. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two I5+ atoms. There are one shorter (1.83 Å) and one longer (2.56 Å) O–I bond lengths. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.83 Å. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.86 Å. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.85 Å. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.83 Å. In the tenth O2- site, O2- is bonded in a distorted tetrahedral geometry to two Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.87 Å. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to two Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.85 Å. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.86 Å. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.85 Å. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to two Ag1+ and one I5+ atom. The O–I bond length is 1.83 Å. In the fifteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ag1+ and one I5+ atom. The O–I bond length is 1.84 Å. In the sixteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the seventeenth O2- site, O2- is bonded in a 1-coordinate geometry to two I5+ atoms. There are one shorter (1.84 Å) and one longer (2.47 Å) O–I bond lengths. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the nineteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the twentieth O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.83 Å. In the twenty-first O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.82 Å. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Bi3+, and one I5+ atom. The O–I bond length is 1.87 Å. In the twenty-third O2- site, O2- is bonded in a 2-coordinate geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.82 Å. In the twenty-fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi3+ and one I5+ atom. The O–I bond length is 1.84 Å. There are eight inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to three O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a 4-coordinate geometry to three O2- atoms. In the fourth I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the fifth I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the sixth I5+ site, I5+ is bonded in a 3-coordinate geometry to four O2- atoms. In the seventh I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the eighth I5+ site, I5+ is bonded in a 4-coordinate geometry to four O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Production of 1,3-Butadiene from Renewable Feedstocks Ethanol and 1,3-Butanediol - CRADA 560 (Final Report)

1,3-butadiene is a commodity chemical currently produced from petroleum sources. Producing 1,3-butadiene from renewable resources will contribute to decarbonization, provide new green jobs, and reduce our dependance on oil. Development of multifunctional catalysts that are active, selective, and stable for this reaction has been an area of research and development. This effort reported here builds on our prior work for the 1-step conversion of ethanol to butadiene. The goal of the additional scope performed here was to accelerate the commercial deployment of sustainable butadiene production. We demonstrated that the PNNL Ag-based catalyst is significantly more active than the WWII-era catalyst when operated under the same conditions. A butadiene selectivity of 68% was obtained at 64% conversion for the production of butadiene from ethanol. It was found that ethanol feedstock is preferred over 1,3-butanediol feedstock to produce butadiene due to higher yield resulting in lower butadiene selling price (i.e., $\$$0.4-1.7/ lb). Production of 3.0 Liter of butadiene solution in hexane containing 100 grams of butadiene was achieved and delivered to Bridgestone for producing a butadiene-derived test piece.

09 BIOMASS FUELS↗
DOE OSTI2020

Materials Data on FeAgBr4 by Materials Project

FeAgBr4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Fe3+ is bonded to four Br1- atoms to form FeBr4 tetrahedra that share corners with two equivalent AgBr6 octahedra and edges with two equivalent AgBr6 octahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are a spread of Fe–Br bond distances ranging from 2.35–2.39 Å. Ag1+ is bonded to six Br1- atoms to form AgBr6 octahedra that share corners with two equivalent AgBr6 octahedra, corners with two equivalent FeBr4 tetrahedra, an edgeedge with one AgBr6 octahedra, and edges with two equivalent FeBr4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Ag–Br bond distances ranging from 2.76–3.15 Å. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a bent 120 degrees geometry to one Fe3+ and one Ag1+ atom. In the second Br1- site, Br1- is bonded in a 3-coordinate geometry to one Fe3+ and two equivalent Ag1+ atoms. In the third Br1- site, Br1- is bonded in an L-shaped geometry to one Fe3+ and one Ag1+ atom. In the fourth Br1- site, Br1- is bonded in a 1-coordinate geometry to one Fe3+ and two equivalent Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta3AgO8 by Materials Project

Ta3AgO8 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. there are four inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 0–35°. There are a spread of Ta–O bond distances ranging from 1.97–2.13 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–33°. There are a spread of Ta–O bond distances ranging from 1.94–2.05 Å. In the third Ta5+ site, Ta5+ is bonded to seven O2- atoms to form TaO7 pentagonal bipyramids that share corners with two equivalent TaO7 pentagonal bipyramids and edges with five TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.97–2.13 Å. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–35°. There are a spread of Ta–O bond distances ranging from 1.94–2.06 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 12-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.35–2.64 Å. In the second Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ag–O bond distances ranging from 2.47–2.91 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ta5+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Ta5+ and two equivalent Ag1+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ta5+ and one Ag1+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ta5+ and one Ag1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ta5+ and two Ag1+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ta5+ and one Ag1+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two Ta5+ and one Ag1+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ta5+ and two equivalent Ag1+ atoms. In the thirteenth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the fourteenth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on V4Ag2O11 by Materials Project

Ag2V4O11 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.67–2.51 Å. In the second V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.64–2.31 Å. Ag1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ag–O bond distances ranging from 2.31–2.45 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one V5+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two V5+ and two equivalent Ag1+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one V5+ and one Ag1+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent V5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three V5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four V5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb4Ag2O11 by Materials Project

Ag2Nb4O11 crystallizes in the trigonal R3c space group. The structure is three-dimensional. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. There are three shorter (1.92 Å) and three longer (2.16 Å) Nb–O bond lengths. In the second Nb5+ site, Nb5+ is bonded to seven O2- atoms to form distorted NbO7 pentagonal bipyramids that share corners with two equivalent NbO6 octahedra, corners with two equivalent NbO7 pentagonal bipyramids, and edges with four equivalent NbO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Nb–O bond distances ranging from 1.89–2.36 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.60–2.85 Å. In the second Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.54 Å) and three longer (2.75 Å) Ag–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Nb5+ and two Ag1+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Nb5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Nb5+ and one Ag1+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Nb5+ and two Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb2AgPS10 by Materials Project

AgNb2PS10 crystallizes in the monoclinic C2/c space group. The structure is two-dimensional and consists of two AgNb2PS10 sheets oriented in the (1, 0, 0) direction. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to eight S+1.60- atoms to form NbS8 hexagonal bipyramids that share an edgeedge with one PS4 tetrahedra and faces with two equivalent NbS8 hexagonal bipyramids. There are a spread of Nb–S bond distances ranging from 2.50–2.68 Å. In the second Nb5+ site, Nb5+ is bonded to eight S+1.60- atoms to form distorted NbS8 hexagonal bipyramids that share an edgeedge with one PS4 tetrahedra and faces with two equivalent NbS8 hexagonal bipyramids. There are a spread of Nb–S bond distances ranging from 2.49–2.68 Å. Ag1+ is bonded in a 6-coordinate geometry to six S+1.60- atoms. There are a spread of Ag–S bond distances ranging from 2.59–3.45 Å. P5+ is bonded to four S+1.60- atoms to form PS4 tetrahedra that share edges with two NbS8 hexagonal bipyramids. There are a spread of P–S bond distances ranging from 2.03–2.08 Å. There are ten inequivalent S+1.60- sites. In the first S+1.60- site, S+1.60- is bonded in a 3-coordinate geometry to two Nb5+ and one P5+ atom. In the second S+1.60- site, S+1.60- is bonded in a 3-coordinate geometry to two Nb5+ and one S+1.60- atom. The S–S bond length is 2.05 Å. In the third S+1.60- site, S+1.60- is bonded in a 2-coordinate geometry to one Nb5+, one Ag1+, and one P5+ atom. In the fourth S+1.60- site, S+1.60- is bonded in a distorted trigonal non-coplanar geometry to one Nb5+, one Ag1+, and one P5+ atom. In the fifth S+1.60- site, S+1.60- is bonded in a 4-coordinate geometry to two Nb5+, one Ag1+, and one S+1.60- atom. The S–S bond length is 2.05 Å. In the sixth S+1.60- site, S+1.60- is bonded in a 3-coordinate geometry to two equivalent Ag1+ and one P5+ atom. In the seventh S+1.60- site, S+1.60- is bonded in a 2-coordinate geometry to two Nb5+ and one S+1.60- atom. The S–S bond length is 2.03 Å. In the eighth S+1.60- site, S+1.60- is bonded in a 2-coordinate geometry to two Nb5+ and one S+1.60- atom. In the ninth S+1.60- site, S+1.60- is bonded in a 3-coordinate geometry to two Nb5+ and one S+1.60- atom. In the tenth S+1.60- site, S+1.60- is bonded in a 4-coordinate geometry to two Nb5+, one Ag1+, and one S+1.60- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeAg(MoO4)2 by Materials Project

FeAgMo2O8 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Mo6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mo–O bond distances ranging from 1.75–2.28 Å. Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.17 Å. Ag1+ is bonded to six O2- atoms to form distorted edge-sharing AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.39–2.48 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Mo6+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mo6+ and one Ag1+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mo6+ and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mo6+ and two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaAgAsO4 by Materials Project

CaAgAsO4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent AsO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are two shorter (2.34 Å) and four longer (2.42 Å) Ca–O bond lengths. Ag1+ is bonded in a 6-coordinate geometry to four O2- atoms. There are two shorter (2.30 Å) and two longer (2.59 Å) Ag–O bond lengths. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 43–52°. There is two shorter (1.71 Å) and two longer (1.74 Å) As–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ag1+, and one As5+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+, one Ag1+, and one As5+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2000

Stress-induced reactivation of Epstein-Barr virus in astronauts

Herpesviruses are leading causes of infectious blindness and death in immunocompromised individuals. Impaired cellular immunity, which is known to result in increased frequency and severity of herpesvirus infections, has been demonstrated both during and after spaceflight. Therefore, we examined whether Epstein-Barr virus (EBV), a well-characterized latent herpesvirus, undergoes reactivation in astronauts. Sera from Shuttle astronauts, taken before and after spaceflight, were examined for evidence of EBV reactivation. The geometric mean antibody titer to EBV viral capsid antigen (VCA) was significantly increased prior to flight compared to baseline (p = 0. 0001). After spaceflight, evidence of acute lytic replication was found in which 8- to 64-fold increases in EBV early antigen (EA) antibodies occurred without significant increases in antibodies to measles virus. Additionally, stress-induced shifts in circulating leukocytes and elevated levels of urinary cortisol and epinephrine were found. Overall, significant increases in EA or high VCA/EA antibody titers were found in 8 of 23 (35%) male astronauts and 3 of 5 (60%) female astronauts. These results indicate that stress reactivates EBV prior to flight and suggest that acute lytic replication of EBV occurs during spaceflight. Copyright 2000 S. Karger AG, Basel.

NASA Discipline Environmental Health↗
DOE OSTI2020

Materials Data on NaMn3Ag(PO4)3 by Materials Project

NaMn3Ag(PO4)3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.65 Å. There are two inequivalent Mn+2.33+ sites. In the first Mn+2.33+ site, Mn+2.33+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.22–2.30 Å. In the second Mn+2.33+ site, Mn+2.33+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra and edges with two MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.01–2.19 Å. Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ag–O bond distances ranging from 2.50–2.94 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six MnO6 octahedra. The corner-sharing octahedra tilt angles range from 40–58°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six MnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–61°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mn+2.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Mn+2.33+, one Ag1+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Mn+2.33+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mn+2.33+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Mn+2.33+, one Ag1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Mn+2.33+, two equivalent Ag1+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn2FeAg2(PO4)3 by Materials Project

Ag2FeMn2(PO4)3 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one AgO8 hexagonal bipyramid, and edges with two equivalent MnO6 octahedra. There are two shorter (2.23 Å) and four longer (2.25 Å) Mn–O bond lengths. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with two equivalent AgO8 hexagonal bipyramids, corners with six PO4 tetrahedra, and edges with two equivalent FeO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.20–2.33 Å. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one AgO8 hexagonal bipyramid, an edgeedge with one MnO6 octahedra, and an edgeedge with one FeO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.08–2.34 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one AgO8 hexagonal bipyramid, and edges with two MnO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.18 Å. There are three inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.40–2.69 Å. In the second Ag1+ site, Ag1+ is bonded to eight O2- atoms to form distorted AgO8 hexagonal bipyramids that share corners with two equivalent MnO6 octahedra, corners with two equivalent PO4 tetrahedra, edges with two equivalent FeO6 octahedra, edges with three MnO6 octahedra, and edges with three PO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ag–O bond distances ranging from 2.59–2.94 Å. In the third Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ag–O bond distances ranging from 2.41–3.02 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one AgO8 hexagonal bipyramid, corners with two equivalent FeO6 octahedra, and corners with four MnO6 octahedra. The corner-sharing octahedra tilt angles range from 36–62°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra, corners with four MnO6 octahedra, and an edgeedge with one AgO8 hexagonal bipyramid. The corner-sharing octahedra tilt angles range from 36–61°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra, corners with four MnO6 octahedra, and an edgeedge with one AgO8 hexagonal bipyramid. The corner-sharing octahedra tilt angles range from 47–66°. There is two shorter (1.53 Å) and two longer (1.59 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with four MnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–59°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Fe3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Fe3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Mn2+, one Ag1+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Fe3+, one Ag1+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Mn2+, one Ag1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Fe3+, one Ag1+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Mn2+, two equivalent Ag1+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Mn2+, two equivalent Ag1+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Mn2+, two Ag1+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Fe3+, two Ag1+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ag1+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Fe3+, one Ag1+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Iodine Capture with Metal-Functionalized Polyacrylonitrile Composite Beads Containing Ag 0 , Bi 0 , Cu 0 , or Sn 0 Particles

The capture of radioiodine from nuclear processes and the mitigation of environmental release are important topic areas of research. Some of the more commonly employed chemisorption-type iodine scavengers reported in the literature are based on metal-exchanged porous sorbents such as Ag-zeolites or metal-functionalized aerogels and xerogels. However, another option is to use zero-valent metals directly that have known high affinities for iodine gas [i.e., I2(g)]. In this study, fine metal particles of Ag0, Bi0, Cu0, and Sn0 were embedded in porous polyacrylonitrile (PAN) substrates at 75 mass% metal loadings within the form of ellipsoidal beads with maximum diameters of ~2–3 mm. These composite beads showed extremely high iodine loadings that are directly related to the metal particle loadings. The X-ray diffraction (XRD) analyses of Ag0, Bi0, Cu0, and Sn0 particles as well as metal-PAN composite beads reacted with iodine gas at 120 ± 1 °C showed phases of AgI, BiI3, CuI, and SnI4, respectively. For the Ag-PAN, Cu-PAN, and Sn-PAN beads, no other crystalline peaks were observed in XRD for unreacted metal or oxidized metals after 48 h in saturated I2(g) at 120 ± 1 °C, whereas unreacted metallic Bi0 was observed within the Bi-PAN composites. However, after a 72 h exposure at 120 ± 1 °C, both the Bi0 particles and the Bi-PAN composites showed full conversion from Bi0 to BiI3 with XRD. Comparisons between mass uptake data and X-ray absorption spectroscopy were used to better understand the phase distribution of the Bi phases present in the Bi-PAN+I composites. The iodine loadings (mg iodine per g sorbent, or qe) for these materials were 1120 (Ag-Particle), 1382 (Bi-Particle-72h), 1033 (Cu-Particle), 3000 (Sn-Particle), 753 (Ag-PAN), 1012 (Bi-PAN-72h), 1457 (Cu-PAN), and 1669 (Sn-PAN). It is possible that inexpensive sorbents such as these could be deployed to help limit or prevent release of radioiodine to the environment.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TlAgTeO3 by Materials Project

AgTlTeO3 crystallizes in the orthorhombic Iba2 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 2.35–3.10 Å. Tl1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Tl–O bond distances ranging from 2.62–3.16 Å. Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There is one shorter (1.90 Å) and two longer (1.91 Å) Te–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+, one Tl1+, and one Te4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ag1+, one Tl1+, and one Te4+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to one Ag1+, three equivalent Tl1+, and one Te4+ atom.

36 MATERIALS SCIENCE↗