1
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Sowers TD, Blackmon MD, Wilkin RT, Rovero M, Bone SE, Jerden ML, Nelson CM, Bradham KD. Lead Speciation, Bioaccessibility, and Sources for a Contaminated Subset of House Dust and Soils Collected from Similar United States Residences. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9339-9349. [PMID: 38748567 DOI: 10.1021/acs.est.4c01594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Residential lead (Pb) exposure is of critical concern to families globally as Pb promotes severe neurological effects in children, especially those less than 5 years old, and no blood lead level is deemed safe by the US Center for Disease Control. House dust and soils are commonly thought to be important sources of Pb exposure. Probing the relationship between house dust and soil Pb is critical to understanding residential exposure, as Pb bioavailability is highly influenced by Pb sources and/or species. We investigated paired house dust and soil collected from homes built before 1978 to determine Pb speciation, source, and bioaccessibility with the primary goal of assessing chemical factors driving Pb exposure in residential media. House dust was predominately found to contain (hydro)cerussite (i.e., Pb (hydroxy)carbonate) phases commonly used in Pb-based paint that, in-turn, promoted elevated bioaccessibility (>60%). Pb X-ray absorption spectroscopy, μ-XRF mapping, and Pb isotope ratio analysis for house dust and soils support house dust Pb as chemically unique compared to exterior soils, although paint Pb is expected to be a major source for both. Soil pedogenesis and increased protection from environmental conditions (e.g., weathering) in households is expected to greatly impact Pb phase differences between house dust and soils, subsequently dictating differences in Pb exposure.
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Affiliation(s)
- Tyler D Sowers
- Center for Environmental Measurement and Modeling, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Matthew D Blackmon
- Center for Environmental Measurement and Modeling, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Richard T Wilkin
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Ada, Oklahoma 74820, United States
| | - Matt Rovero
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Ada, Oklahoma 74820, United States
| | - Sharon E Bone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Marissa L Jerden
- Jacobs Technology, Inc., 109 T.W. Alexander Drive, RTP, North Carolina 27711, United States
| | - Clay M Nelson
- BioGeoChem Scientific, Austin, Texas 78748, United States
| | - Karen D Bradham
- Center for Environmental Measurement and Modeling, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
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2
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Lee JH, Bae JG, Kim MS, Heo JY, Lee HJ, Lee JH. Effect of the Interaction between Transition Metal Redox Center and Cyanide Ligand on Structural Evolution in Prussian White Cathodes. ACS NANO 2024; 18:1995-2005. [PMID: 38214304 DOI: 10.1021/acsnano.3c08271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Transition metal (TM) based Prussian whites, comprising a cyanide anion ((C≡N)-) and TM cations in an alternative manner, have been widely adopted as cathode materials for rechargeable batteries. Prussian whites are characterized by the TM electronic states that exclusively adopt low spin (LS) toward the C atom and high spin (HS) toward the N atom through the hybridized covalent bonding in the TM─C≡N─TM unit with the average oxidation states of the TM ions being 2+, considerably affecting the phase transition behavior upon the release and storage of carrier ions; however, there have been only a few studies on their associated features. Herein, Prussian whites with different HS TM ions were synthesized via coprecipitation and the phase transition behavior controlled by the π electron interaction between the cyanide anions and TM ions during battery operations was investigated. In situ X-ray characterizations reveal that the combined effect of π backdonation in the LS Fe-C unit and π donation in the HS TM-N unit effectively controls the bond length of the TM─C≡N─TM building unit, thus markedly influencing the lattice volume of a series of Prussian white cathodes during the charge/discharge process. This study presents a comprehensive understanding of the structure-property relationship of the Prussian white cathodes involving π electron interactions during battery operations.
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Affiliation(s)
- Ju-Hyeon Lee
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
- KNU Advanced Material Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jin-Gyu Bae
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
- KNU Advanced Material Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Min Sung Kim
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
- KNU Advanced Material Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jeong Yeon Heo
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
- KNU Advanced Material Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyeon Jeong Lee
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Ji Hoon Lee
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
- KNU Advanced Material Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
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3
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Vennapoosa CS, Varangane S, Abraham BM, Bhasin V, Bhattacharyya S, Wang X, Pal U, Chatterjee D. Single-Atom Ru Catalyst-Decorated CNF(ZnO) Nanocages for Efficient H 2 Evolution and CH 3OH Production. J Phys Chem Lett 2023; 14:11400-11411. [PMID: 38079360 DOI: 10.1021/acs.jpclett.3c02347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The presence of transition-metal single-atom catalysts effectively enhances the interaction between the substrate and reactant molecules, thus exhibiting extraordinary catalytic performance. In this work, we for the first time report a facile synthetic procedure for placing highly dispersed Ru single atoms on stable CNF(ZnO) nanocages. We unravel the atomistic nature of the Ru single atoms in CNF(ZnO)/Ru systems using advanced HAADF-STEM, HRTEM, and XANES analytical methods. Density functional theory calculations further support the presence of ruthenium single-atom sites in the CNF(ZnO)/Ru system. Our work further demonstrates the excellent photocatalytic ability of the CNF(ZnO)/Ru system with respect to H2 production (5.8 mmol g-1 h-1) and reduction of CO2 to CH3OH [249 μmol (g of catalyst)-1] with apparent quantum efficiencies of 3.8% and 1.4% for H2 and CH3OH generation, respectively. Our studies unambiguously demonstrate the presence of atomically dispersed ruthenium sites in CNF(ZnO)/Ru catalysts, which greatly enhance charge transfer, thus facilitating the aforementioned photocatalytic redox reactions.
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Affiliation(s)
- Chandra Shobha Vennapoosa
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad, Telangana 500007, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Sagar Varangane
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad, Telangana 500007, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - B Moses Abraham
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Vidha Bhasin
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | | | - Xuefeng Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ujjwal Pal
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad, Telangana 500007, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Debabrata Chatterjee
- Vice-Chancellor's Research Group, Zoology Department, University of Burdwan, Burdwan 713104, India
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4
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Subhash B, Unocic RR, Lie WH, Gallington LC, Wright J, Cheong S, Tilley RD, Bedford NM. Resolving Atomic-Scale Structure and Chemical Coordination in High-Entropy Alloy Electrocatalysts for Structure-Function Relationship Elucidation. ACS NANO 2023; 17:22299-22312. [PMID: 37944052 DOI: 10.1021/acsnano.3c03884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The recent breakthrough in confining five or more atomic species in nanocatalysts, referred to as high-entropy alloy nanocatalysts (HEAs), has revealed the possibilities of multielemental interactions that can surpass the limitations of binary and ternary electrocatalysts. The wide range of potential surface configurations in HEAs, however, presents a significant challenge in resolving active structural motifs, preventing the establishment of structure-function relationships for rational catalyst design and optimization. We present a methodology for creating sub-5 nm HEAs using an aqueous-based peptide-directed route. Using a combination of pair distribution function and X-ray absorption spectroscopy, HEA structure models are constructed from reverse Monte Carlo modeling of experimental data sets and showcase a clear peptide-induced influence on atomic-structure and chemical miscibility. Coordination analysis of our structure models facilitated the construction of structure-function correlations applied to electrochemical methanol oxidation reactions, revealing the complex interplay between multiple metals that leads to improved catalytic properties. Our results showcase a viable strategy for elucidating structure-function relationships in HEAs, prospectively providing a pathway for future materials design.
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Affiliation(s)
- Bijil Subhash
- School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - William Hadinata Lie
- School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Leighanne C Gallington
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Joshua Wright
- Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616, United States
| | - Soshan Cheong
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Richard D Tilley
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nicholas M Bedford
- School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
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5
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Li B, Jones ZR, Eiroa-Lledo C, Knope KE, Mocko V, Stein BW, Wacker JN, Kozimor SA, Batista ER, Yang P. Structure and Dynamics of NaCl/KCl/CaCl 2-EuCl n ( n = 2, 3) Molten Salts. Inorg Chem 2023. [PMID: 37379331 DOI: 10.1021/acs.inorgchem.2c03982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
Modern molten salt reactor design and the techniques of electrorefining spent nuclear fuels require a better understanding of the chemical and physical behavior of lanthanide/actinide ions with different oxidation states dissolved in various solvent salts. The molecular structures and dynamics that are driven by the short-range interactions between solute cations and anions and long-range solute and solvent cations are still unclear. In order to study the structural change of solute cations caused by different solvent salts, we performed first-principles molecular dynamics simulations in molten salts and extended X-ray absorption fine structure (EXAFS) measurements for the cooled molten salt samples to identify the local coordination environment of Eu2+ and Eu3+ ions in CaCl2, NaCl, and KCl. The simulations reveal that with the increasing polarizing the outer sphere cations from K+ to Na+ to Ca2+, the coordination number (CN) of Cl- in the first solvation shell increases from 5.6 (Eu2+) and 5.9 (Eu3+) in KCl to 6.9 (Eu2+) and 7.0 (Eu3+) in CaCl2. This coordination change is validated by the EXAFS measurements, in which the CN of Cl- around Eu increases from 5 in KCl to 7 in CaCl2. Our simulation shows that the fewer Cl- ions coordinated to Eu leads to a more rigid first coordination shell with longer lifetime. Furthermore, the diffusivities of Eu2+/Eu3+ are related to the rigidity of their first coordination shell of Cl-: the more rigid the first coordination shell is, the slower the solute cations diffuse.
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Affiliation(s)
- Bo Li
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Zachary R Jones
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Cecilia Eiroa-Lledo
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Karah E Knope
- Department of Chemistry, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, United States
| | - Veronika Mocko
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Benjamin W Stein
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jennifer N Wacker
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Department of Chemistry, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, United States
| | - Stosh A Kozimor
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Enrique R Batista
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Ping Yang
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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6
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Bae JG, Lee JH, Kim MS, Kim BG, Lee HJ, Lee JH. Structural Evolution of Mg-Doped Single-Crystal LiCoO 2 Cathodes: Importance of Morphology and Mg-Doping Sites. ACS APPLIED MATERIALS & INTERFACES 2023; 15:7939-7948. [PMID: 36625754 DOI: 10.1021/acsami.2c17993] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Layered lithium cobalt oxide (LiCoO2, LCO), which serves as a structural motif for the widely adopted layered cathodes in lithium-ion batteries, has a long history, and its unstable phase transition during high-voltage operation (∼4.5 V) remains an intractable problem. Many research strategies, such as surface coating and immobile ion doping, have been proposed to address this issue, but a clear understanding of the effects has not been demonstrated because of various potential parameters (e.g., particle size, shape, and dopant content). Herein, we report a molten salt synthesis method that produces sphere-like single-crystal magnesium (Mg)-doped LCO. In situ X-ray diffraction and X-ray absorption fine structure analyses confirmed that the lattice strain was effectively alleviated by the effects of both the particle shape and Mg doping compared to the plate-like and sphere-like single-crystal LCO samples. Furthermore, the preference for Mg doping in the Co site (3b) rather than in the Li site (3a) in the LCO framework is systematically revealed, and a clear understanding of Mg doping that suppresses the monoclinic phase transition is discussed in detail.
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Affiliation(s)
- Jin-Gyu Bae
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Ju-Hyeon Lee
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Min Sung Kim
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Byung Gon Kim
- Next Generation Battery Research Center, Korea Electrotechnology Research Institute (KERI), 12 Jeongiui-gil, Seongsan-gu, Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Hyeon Jeong Lee
- Division of Chemical Engineering and Bioengineering, Kangwon National University, Chuncheon, Gangwon-do 24341, Republic of Korea
| | - Ji Hoon Lee
- School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
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7
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Sarkar P, Biswas A, Kumar R, Rai S, Jha SN, Bhattacharyya D. Role of C and B 4C barrier layers in controlling diffusion propagation across the interface of Cr/Sc multilayers. Phys Chem Chem Phys 2023; 25:3072-3082. [PMID: 36620902 DOI: 10.1039/d2cp03785h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The optical performance of low-bilayer-thickness metallic multilayers (ML) can be improved significantly by limiting the intermixing of consecutive layers at the interfaces. Barrier layers are supposed to exhibit a decisive role in controlling diffusion across the interfaces. The element-specific grazing incidence extended X-ray absorption fine structure technique using synchrotron radiation has been used in conjunction with grazing incidence X-ray reflectivity and diffuse X-ray scattering measurements to study the impact of the two most common barrier layers, viz., C and B4C, at the interfaces of Cr/Sc MLs. The diffusion propagation is reduced by both the barrier layers; however, it is found that the improvement is more significant with the B4C barrier layer. It is seen that C forms an intermixed layer with Sc and leads to carbide formation at the interface, which then acts as shielding and prevents further interdiffusion, while B4C hardly penetrates into Sc and stops the overlap between Sc and Cr directly by wetting the corresponding interface. Thus, the above measurements reveal crucial and precise information regarding the elemental diffusion kinetics at the interfaces of Cr/Sc MLs in a non-destructive way, which is very important for technological applications of these MLs as X-ray optical devices.
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Affiliation(s)
- P Sarkar
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
| | - A Biswas
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
| | - Ravi Kumar
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
| | - S Rai
- Synchrotron Utilisation Section, Raja Ramnna Centre for Advanced Technology, Indore 752013, India
| | - S N Jha
- Beamline Development & Applications Section Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - D Bhattacharyya
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
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8
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Gonuguntla S, Sk S, Tripathi A, Thapa R, Jonnalagadda G, Nayak C, Bhattacharyya D, Jha SN, Sesha Sainath AV, Perupogu V, Pal U. Anisotropic phenanthroline-based ruthenium polymers grafted on a titanium metal-organic framework for efficient photocatalytic hydrogen evolution. Commun Chem 2022; 5:165. [PMID: 36697663 PMCID: PMC9814133 DOI: 10.1038/s42004-022-00763-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/25/2022] [Indexed: 12/04/2022] Open
Abstract
Conjugated polymers and titanium-based metal-organic framework (Ti-MOF) photocatalysts have demonstrated promising features for visible-light-driven hydrogen production. We report herein a strategy of anisotropic phenanthroline-based ruthenium polymers (PPDARs) over Ti-MOF, a tunable platform for efficient visible-light-driven photocatalytic hydrogen evolution reaction (HER). Several analytical methods including X-ray absorption spectroscopy (XAS) revealed the judicious integration of the surface-active polymer over the Ti-MOF reinforcing the catalytic activity over the broad chemical space. PPDAR-4 polyacrylate achitecture led to a substantial increase in the H2 evolution rate of 2438 µmolg-1h-1 (AQY: 5.33%) compared to pristine Ti-MOF (238 µmol g-1 h-1). The separation of photogenerated charge carriers at the PPDAR-4/Ti-MOF interface was confirmed by the optical and electrochemical investigations. The experimental, as well as theoretical data, revealed their physical and chemical properties which are positively correlated with the H2 generation rate. This offers a new avenue in creating polymer-based MOF robust photocatalysts for sustainable energy.
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Affiliation(s)
- Spandana Gonuguntla
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India
| | - Saddam Sk
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India
| | - Anjana Tripathi
- Department of Physics, SRM University-AP, Amravati-, 522502, Andhra Pradesh, India
| | - Ranjit Thapa
- Department of Physics, SRM University-AP, Amravati-, 522502, Andhra Pradesh, India
| | - Gopinath Jonnalagadda
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India.,Polymers and Functional Materials, Fluoro-Agrochemicals Department, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India
| | - Chandrani Nayak
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai-, 400085, India
| | - Dibyendu Bhattacharyya
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai-, 400085, India
| | - S N Jha
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai-, 400085, India
| | - Annadanam V Sesha Sainath
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India.,Polymers and Functional Materials, Fluoro-Agrochemicals Department, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India
| | - Vijayanand Perupogu
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India
| | - Ujjwal Pal
- Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Hyderabad-, 500007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India.
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9
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Rana R, Vila FD, Kulkarni AR, Bare SR. Bridging the Gap between the X-ray Absorption Spectroscopy and the Computational Catalysis Communities in Heterogeneous Catalysis: A Perspective on the Current and Future Research Directions. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rachita Rana
- Department of Chemical Engineering, University of California, Davis, California95616, United States
| | - Fernando D. Vila
- Department of Physics, University of Washington, Seattle, Washington98195, United States
| | - Ambarish R. Kulkarni
- Department of Chemical Engineering, University of California, Davis, California95616, United States
| | - Simon R. Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California94025, United States
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10
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Chang Q, Lee JH, Liu Y, Xie Z, Hwang S, Marinkovic NS, Park AHA, Kattel S, Chen JG. Electrochemical CO 2 Reduction Reaction over Cu Nanoparticles with Tunable Activity and Selectivity Mediated by Functional Groups in Polymeric Binder. JACS AU 2022; 2:214-222. [PMID: 35098238 PMCID: PMC8790809 DOI: 10.1021/jacsau.1c00487] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Indexed: 06/14/2023]
Abstract
The electrochemical carbon dioxide reduction reaction (CO2RR) using copper (Cu)-based catalysts has received significant attention mainly because Cu is an element capable of producing hydrocarbons and oxygenates. One possible way to control the CO2RR performance at the electrode interface is by modifying catalysts with specific functional groups of different polymeric binders, which are necessary components in the process of electrode fabrication. However, the modification effect of the key functional groups on the CO2RR activity and selectivity is poorly understood over Cu-based catalysts. In this work, the role of functional groups (e.g., -COOH and -CF2 groups) in hydrophilic and hydrophobic polymeric binders on the CO2RR of Cu-based catalysts is investigated using a combination of electrochemical measurements, in situ characterization, and density functional theory (DFT) calculations. DFT results reveal that functional groups influence the binding energies of key intermediates involved in both CO2RR and the competing hydrogen evolution reaction, consistent with experimental observation of binder-dependent product distributions among formic acid, CO, CH4, and H2. This study provides a fundamental understanding that the selection of desired polymeric binders is a useful strategy for tuning the CO2RR activity and selectivity.
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Affiliation(s)
- Qiaowan Chang
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Ji Hoon Lee
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
- School
of Materials Science and Engineering, Kyungpook
National University, Daegu 41566, Republic of Korea
| | - Yumeng Liu
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Zhenhua Xie
- Chemistry
Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Sooyeon Hwang
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | - Nebojsa S. Marinkovic
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Ah-Hyung Alissa Park
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
- Department
of Earth and Environmental Engineering, Columbia University, New York, New York 10027, United States
- Lenfest Center
for Sustainable Energy, The Earth Institute, Columbia University, New York, New York 10027, United States
| | - Shyam Kattel
- Department
of Physics, Florida A&M University, Tallahassee, Florida 32307, United States
| | - Jingguang G. Chen
- Department
of Chemical Engineering, Columbia University, New York, New York 10027, United States
- Chemistry
Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Lenfest Center
for Sustainable Energy, The Earth Institute, Columbia University, New York, New York 10027, United States
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11
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Abbaspour Tamijani A, Augustine LJ, Bjorklund JL, Catalano JG, Mason SE. First-principles characterisation and comparison of clean, hydrated, and defect α-Al2O3 and α-Fe2O3 (110) surfaces. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2021.2009117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | | | - Jeffrey G. Catalano
- Department of Earth and Planetary Sciences, Washington University, St. Louis, USA
| | - Sara E. Mason
- Department of Chemistry, University of Iowa, Iowa City, USA
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12
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Musino D, Devcic J, Lelong C, Luche S, Rivard C, Dalzon B, Landrot G, Rabilloud T, Capron I. Impact of Physico-Chemical Properties of Cellulose Nanocrystal/Silver Nanoparticle Hybrid Suspensions on Their Biocidal and Toxicological Effects. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1862. [PMID: 34361248 PMCID: PMC8308223 DOI: 10.3390/nano11071862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/08/2021] [Accepted: 07/16/2021] [Indexed: 12/11/2022]
Abstract
There is a demand for nanoparticles that are environmentally acceptable, but simultaneously efficient and low cost. We prepared silver nanoparticles (AgNPs) grafted on a native bio-based substrate (cellulose nanocrystals, CNCs) with high biocidal activity and no toxicological impact. AgNPs of 10 nm are nucleated on CNCs in aqueous suspension with content from 0.4 to 24.7 wt%. XANES experiments show that varying the NaBH4/AgNO3 molar ratio affects the AgNP oxidation state, while maintaining an fcc structure. AgNPs transition from 10 nm spherical NPs to 300 nm triangular-shaped AgNPrisms induced by H2O2 post-treatment. The 48 h biocidal activity of the hybrid tested on B. Subtilis is intensified with the increase of AgNP content irrespective of the Ag+/Ag0 ratio in AgNPs, while the AgNSphere-AgNPrism transition induces a significant reduction of biocidal activity. A very low minimum inhibitory concentration of 0.016 mg AgNP/mL is determined. A new long-term biocidal activity test (up to 168 h) proved efficiency favorable to the smaller AgNPs. Finally, it is shown that AgNPs have no impact on the phagocytic capacity of mammalian cells.
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Affiliation(s)
- Dafne Musino
- INRAE, Institut National de Recherche Pour L’agriculture, L’alimentation et L’environnement, BIA, Biopolymères Interactions et Assemblages, 44316 Nantes, France;
| | - Julie Devcic
- Laboratoire de Chimie et Biologie des Métaux, University Grenoble Alpes, CNRS, CEA, IRIG, CBM, UMR5249, 38000 Grenoble, France; (J.D.); (C.L.); (S.L.); (B.D.)
| | - Cécile Lelong
- Laboratoire de Chimie et Biologie des Métaux, University Grenoble Alpes, CNRS, CEA, IRIG, CBM, UMR5249, 38000 Grenoble, France; (J.D.); (C.L.); (S.L.); (B.D.)
| | - Sylvie Luche
- Laboratoire de Chimie et Biologie des Métaux, University Grenoble Alpes, CNRS, CEA, IRIG, CBM, UMR5249, 38000 Grenoble, France; (J.D.); (C.L.); (S.L.); (B.D.)
| | - Camille Rivard
- SOLEIL Synchrotron, L’Orme des Merisiers, Gif-sur-Yvette, 91192 Saint-Aubin, France; (C.R.); (G.L.)
- INRAE, Institut National de Recherche Pour L’agriculture, L’alimentation et L’environnement, BIA, TRANSFORM, 44316 Nantes, France
| | - Bastien Dalzon
- Laboratoire de Chimie et Biologie des Métaux, University Grenoble Alpes, CNRS, CEA, IRIG, CBM, UMR5249, 38000 Grenoble, France; (J.D.); (C.L.); (S.L.); (B.D.)
| | - Gautier Landrot
- SOLEIL Synchrotron, L’Orme des Merisiers, Gif-sur-Yvette, 91192 Saint-Aubin, France; (C.R.); (G.L.)
| | - Thierry Rabilloud
- Laboratoire de Chimie et Biologie des Métaux, University Grenoble Alpes, CNRS, CEA, IRIG, CBM, UMR5249, 38000 Grenoble, France; (J.D.); (C.L.); (S.L.); (B.D.)
| | - Isabelle Capron
- INRAE, Institut National de Recherche Pour L’agriculture, L’alimentation et L’environnement, BIA, Biopolymères Interactions et Assemblages, 44316 Nantes, France;
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Van Groeningen N, Christl I, Kretzschmar R. The Effect of Aeration on Mn(II) Sorbed to Clay Minerals and Its Impact on Cd Retention. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1650-1658. [PMID: 33444011 DOI: 10.1021/acs.est.0c05875] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Manganese is a redox-sensitive element in soils and sediments that plays an important role in the retention of trace elements. Under anoxic conditions, clay minerals were shown to increase Cd retention by favoring the precipitation of Mn(II) phases. In this study, we investigated the influence of aeration on anoxically formed Mn solid phases and its impact on Cd retention in the presence of two clay minerals with low Fe contents, a natural kaolinite (KGa-1b) and a synthetic montmorillonite (Syn-1). Ca-saturated KGa-1b and Syn-1 were pre-equilibrated with Mn2+ and Cd2+ under anoxic conditions for 1 or 30 days and subsequently exposed to air for 1 or 30 days. The analysis with synchrotron X-ray absorption spectroscopy (XAS) revealed that extended anoxic pre-equilibration (30 days) partially prevented the oxidation of sorbed Mn(II) (MnSiO3 and Mn(II)Al-LDH). Extended exposure to ambient air and short anoxic pre-equilibration favored the formation of feitknechtite (β-MnOOH) and birnessite (δ-MnO2). Aeration resulted in a decrease of pH and a net release of Cd2+ into the solution, indicating that Cd re-sorption by Mn(III/IV)-phases was insufficient to compensate for the release of Cd2+ due to dissolution of Mn(II)-containing phases and the decrease in pH. Our results demonstrate the significance of clay minerals in the (trans)formation of Mn-containing phases and their impact on trace metal retention in environments undergoing fluctuating redox conditions.
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Affiliation(s)
- Natacha Van Groeningen
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland
| | - Iso Christl
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland
| | - Ruben Kretzschmar
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland
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Van Groeningen N, Glück B, Christl I, Kretzschmar R. Surface precipitation of Mn 2+ on clay minerals enhances Cd 2+ sorption under anoxic conditions. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:1654-1665. [PMID: 32627793 DOI: 10.1039/d0em00155d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The influence of Mn2+ on the sorption of metal(loid)s onto clay minerals is still unclear despite its relevance in suboxic and anoxic environments which often exhibit elevated dissolved Mn2+ concentrations. In this study, the effects of Mn2+ on Cd2+ sorption to two types of clay minerals, a well-crystalline natural kaolinite (KGa-1b) and a synthetic montmorillonite (Syn-1), were investigated. Batch experiments on Mn2+ and Cd2+ sorption to Ca-saturated KGa-1b and Syn-1 were conducted under anoxic conditions. At low Mn2+ and Cd2+ concentrations (1 and 5 µM), both metals exhibited similar affinity for sorption to the clays, suggesting that elevated Mn2+ concentrations might effectively decrease Cd2+ sorption as predicted using a three-plane surface complexation model. However, competitive Mn-Cd experiments at higher concentrations (≥50 µM) revealed that for both clay minerals, the presence of Mn2+ increased Cd2+ sorption to the solid phases. Although solutions were undersaturated with respect to known Mn(ii) solid phases, analysis using X-ray absorption spectroscopy (XAS) evidenced the formation of Mn(ii)-containing solid phases which can specifically adsorb or incorporate Cd2+. This process, which was mediated by the presence of clay minerals, overcompensated the decrease in Cd2+ adsorption to clay surfaces due to competition with Mn2+. We conclude that, contrary to predictions based on a competitive surface complexation model, elevated Mn2+ concentrations can contribute to decrease dissolved Cd2+ concentrations in anoxic clay-containing environments, such as contaminated sediments or flooded paddy soils.
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Affiliation(s)
- Natacha Van Groeningen
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Universitätstrasse 16, CHN, 8092 Zurich, Switzerland.
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Van Groeningen N, ThomasArrigo LK, Byrne JM, Kappler A, Christl I, Kretzschmar R. Interactions of ferrous iron with clay mineral surfaces during sorption and subsequent oxidation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:1355-1367. [PMID: 32374339 DOI: 10.1039/d0em00063a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In submerged soils and sediments, clay minerals are often exposed to anoxic waters containing ferrous iron (Fe2+). Here, we investigated the sorption of Fe2+ onto a synthetic montmorillonite (Syn-1) low in structural Fe (<0.05 mmol Fe per kg) under anoxic conditions and the effects of subsequent oxidation. Samples were prepared at two Fe-loadings (0.05 and 0.5 mol Fe added per kg clay) and equilibrated for 1 and 30 days under anoxic conditions (O2 < 0.1 ppm), followed by exposure to ambient air. Iron solid-phase speciation and mineral identity was analysed by 57Fe Mössbauer spectroscopy and synchrotron X-ray absorption spectroscopy (XAS). Mössbauer analyses showed that Fe(ii) was partially oxidized (14-100% of total added Fe2+) upon sorption to Syn-1 under anoxic conditions. XAS results revealed that the added Fe2+ mainly formed precipitates (layered Fe minerals, Fe(iii)-bearing clay minerals, ferrihydrite, and lepidocrocite) in different quantities depending on the Fe-loading. Exposing the suspensions to ambient air resulted in rapid and complete oxidation of sorbed Fe(ii) and the formation of Fe(iii)-phases (Fe(iii)-bearing clay minerals, ferrihydrite, and lepidocrocite), demonstrating that the clay minerals were unable to protect ferrous Fe from oxidation, even when equilibrated 30 days under anoxic conditions prior to oxidation. Our findings clarify the role of clay minerals in the formation and stability of Fe-bearing solid phases during redox cycles in periodically anoxic environments.
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Affiliation(s)
- Natacha Van Groeningen
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland.
| | - Laurel K ThomasArrigo
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland.
| | - James M Byrne
- Geomicrobiology Group, Centre for Applied Geosciences (ZAG), University of Tübingen, Hölderlinstrasse 12, D-72074, Tübingen, Germany
| | - Andreas Kappler
- Geomicrobiology Group, Centre for Applied Geosciences (ZAG), University of Tübingen, Hölderlinstrasse 12, D-72074, Tübingen, Germany
| | - Iso Christl
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland.
| | - Ruben Kretzschmar
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, 8092 Zürich, Switzerland.
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16
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Rivera NA, Bippus PM, Hsu-Kim H. Relative Reactivity and Bioavailability of Mercury Sorbed to or Coprecipitated with Aged Iron Sulfides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7391-7399. [PMID: 31173690 PMCID: PMC8412064 DOI: 10.1021/acs.est.9b00768] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The potential for inorganic mercury (Hg) to be converted to methylmercury depends, in part, on the chemical form of Hg and its bioavailability to anaerobic microorganisms that can methylate Hg. In anaerobic settings, Hg can be associated with sulfide phases, including ferrous iron sulfide (FeS), which can sorb or be coprecipitated with Hg. The objective of this study was to determine if the aging state of FeS alters the Hg coordination environment as well as the reactivity and bioavailability of sorbed and coprecipitated Hg species. FeS particles were synthesized with and without Hg2+ and aged in anaerobic conditions for multiple time frames spanning from 1 h to 1 month. For FeS particles synthesized without Hg, Hg2+ was subsequently sorbed to the FeS for 1 day. Analysis of Hg speciation of these materials by X-ray absorption near edge spectroscopy revealed a predominance of four-coordinate Hg-S species in the sorbed Hg-FeS solids and a mixture of two- and four-coordinate Hg-S in the coprecipitated Hg-FeS. The leaching potential of the Hg was assessed by exposing the particles to a solution of dissolved glutathione (a thiolate-based Hg chelator). As expected, the sorbed Hg-FeS released more soluble Hg compared to the coprecipitated Hg-FeS. However, when these particles were exposed to Desulfovibrio desulfuricans ND132 (a known Hg methylator), more Hg was methylated from the coprecipitated Hg-FeS than the sorbed Hg-FeS, consistent with expectations from the Hg-S coordination state and inconsistent with the selective leaching results. Overall, these results suggest that the bioavailability of particulate Hg cannot be easily discerned by its leaching potential into bulk solution. Rather, bioavailability entails more subtle interactions at particle-cell interfaces and perhaps correlates with the local Hg-S coordination state in the particles.
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Affiliation(s)
- Nelson A. Rivera
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Paige M. Bippus
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
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Examination of Natural and Standard Fe 3O 4 Powders Using X-Ray Absorption Near-Edge Spectroscopy (XANES). ACTA ACUST UNITED AC 2019. [DOI: 10.4028/www.scientific.net/msf.964.40] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Investigation of Fe K-edge X-Ray Absorption Near Edge Spectroscopy (XANES) spectra of Fe3O4 (FeO.Fe2O3) from natural source compared with the Fe3O4 standard is presented. The natural Fe3O4 powder was prepared from ironstone of Tanah Laut, Kalimantan Selatan by co-precipitation method. XANES measurements in transmission mode were performed at the Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. XRD phase analysis confirms that the synthesized Fe3O4 powder is a single phase, but it cannot determine the proportion of Fe2O3 and FeO in the structure. TEM measurement confirms that the particle size of natural Fe3O4 about 10 nm. Qualitative analysis of the pre-edge XANES data revealed that the absorbing atom in the XAS measurement is Fe3+. Meanwhile, the absorption edge (E0) values of natural and standard Fe3O4 powders were 7126.44 eV and 7125.02 eV, respectively. The proportion was then acquired using XANES data analysis through Linear Combination Fitting (LCF). It was found that the natural Fe3O4 sample consisted of 98 wt. % Fe2O3 and 2 wt.% FeO, while the standard Fe3O4 powder consisted of 96 wt. % Fe2O3 and 4 wt. % FeO. The mechanism of the absorption in both samples is also described and compared.
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Baek J, Rungtaweevoranit B, Pei X, Park M, Fakra SC, Liu YS, Matheu R, Alshmimri SA, Alshehri S, Trickett CA, Somorjai GA, Yaghi OM. Bioinspired Metal–Organic Framework Catalysts for Selective Methane Oxidation to Methanol. J Am Chem Soc 2018; 140:18208-18216. [DOI: 10.1021/jacs.8b11525] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | - Myeongkee Park
- Department of Chemistry, College of Natural Science, Dong-A University, Busan 49315, Republic of Korea
| | | | | | | | | | - Saeed Alshehri
- King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia
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Lindblom SD, Wangeline AL, Valdez Barillas JR, Devilbiss B, Fakra SC, Pilon-Smits EAH. Fungal Endophyte Alternaria tenuissima Can Affect Growth and Selenium Accumulation in Its Hyperaccumulator Host Astragalus bisulcatus. FRONTIERS IN PLANT SCIENCE 2018; 9:1213. [PMID: 30177943 PMCID: PMC6109757 DOI: 10.3389/fpls.2018.01213] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/27/2018] [Indexed: 05/13/2023]
Abstract
Endophytes can enhance plant stress tolerance by promoting growth and affecting elemental accumulation, which may be useful in phytoremediation. In earlier studies, up to 35% elemental selenium (Se0) was found in Se hyperaccumulator Astragalus bisulcatus. Since Se0 can be produced by microbes, the plant Se0 was hypothesized to be microbe-derived. Here we characterize a fungal endophyte of A. bisulcatus named A2. It is common in seeds from natural seleniferous habitat containing 1,000-10,000 mg kg-1 Se. We identified A2 as Alternaria tenuissima via 18S rRNA sequence analysis and morphological characterization. X-ray microprobe analysis of A. bisulcatus seeds that did or did not harbor Alternaria, showed that both contained >90% organic seleno-compounds with C-Se-C configuration, likely methylselenocysteine and glutamyl-methylselenocysteine. The seed Se was concentrated in the embryo, not the seed coat. X-ray microprobe analysis of A2 in pure culture showed the fungus produced Se0 when supplied with selenite, but accumulated mainly organic C-Se-C compounds when supplied with selenate. A2 was completely resistant to selenate up to 300 mg L-1, moderately resistant to selenite (50% inhibition at ∼50 mg Se L-1), but relatively sensitive to methylselenocysteine and to Se extracted from A. bisulcatus (50% inhibition at 25 mg Se L-1). Four-week old A. bisulcatus seedlings derived from surface-sterilized seeds containing endophytic Alternaria were up to threefold larger than seeds obtained from seeds not showing evidence of fungal colonization. When supplied with Se, the Alternaria-colonized seedlings had lower shoot Se and sulfur levels than seedlings from uncolonized seeds. In conclusion, A. tenuissima may contribute to the Se0 observed earlier in A. bisulcatus, and affect host growth and Se accumulation. A2 is sensitive to the Se levels found in its host's tissues, but may avoid Se toxicity by occupying low-Se areas (seed coat, apoplast) and converting plant Se to non-toxic Se0. These findings illustrate the potential for hyperaccumulator endophytes to affect plant properties relevant for phytoremediation. Facultative endophytes may also be applicable in bioremediation and biofortification, owing to their capacity to turn toxic inorganic forms of Se into non-toxic or even beneficial, organic forms with anticarcinogenic properties.
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Affiliation(s)
- Stormy D. Lindblom
- Department of Biology, Colorado State University, Fort Collins, CO, United States
| | - Ami L. Wangeline
- Department of Biology, Laramie County Community College, Cheyenne, WY, United States
| | - Jose R. Valdez Barillas
- Department of Biology, Colorado State University, Fort Collins, CO, United States
- Department of Sciences and Mathematics, Texas A&M University-San Antonio, San Antonio, TX, United States
| | - Berthal Devilbiss
- Department of Biology, Laramie County Community College, Cheyenne, WY, United States
| | - Sirine C. Fakra
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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Salke NP, Rao R, Achary SN, Nayak C, Garg AB, Krishna PSR, Shinde AB, Jha SN, Bhattacharyya D, Jagannath, Tyagi AK. High Pressure Phases and Amorphization of a Negative Thermal Expansion Compound TaVO 5. Inorg Chem 2018; 57:6973-6980. [PMID: 29877695 DOI: 10.1021/acs.inorgchem.8b00590] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Negative thermal expansion material TaVO5 is recently reported to have pressure induced structural phase transition and irreversible amorphization at 0.2 and above 8 GPa, respectively. Here, we have investigated the high pressure phase of TaVO5 using in situ neutron diffraction studies. The first high pressure phase is identified to be monoclinic P21/ c phase, same as the low temperature phase of TaVO5. On heating, amorphous TaVO5 transformed to a new crystalline phase, which showed signatures of higher coordination of vanadium indicating pressure induced amorphization (PIA). PIA observed in TaVO5 might be due to the kinetic hindrance of pressure induced decomposition (PID) into a compound with higher coordination of vanadium. Mechanism of PIA observed in TaVO5 is investigated by carrying out ex situ Raman, XRD, XPS, and XAS measurements. We have also proposed a pressure-temperature phase diagram of TaVO5 qualitatively delineating the phase boundaries between the ambient orthorhombic, monoclinic, and amorphous phases.
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Feld-Cook EE, Bovenkamp-Langlois L, Lomnicki SM. Effect of Particulate Matter Mineral Composition on Environmentally Persistent Free Radical (EPFR) Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10396-10402. [PMID: 28817261 PMCID: PMC5778880 DOI: 10.1021/acs.est.7b01521] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Environmentally Persistent Free Radicals (EPFRs) are newly discovered, long-lived surface bound radicals that form on particulate matter and combustion borne particulates, such as fly ash. Human exposure to such particulates lead to translocation into the lungs and heart resulting in cardio-vascular and respiratory disease through the production of reactive oxygen species. Analysis of some waste incinerator fly ashes revealed a significant difference between their EPFR contents. Although EPFR formation occurs on the metal domains, these differences were correlated with the altering concentration of calcium and sulfur. To analyze these phenomena, surrogate fly ashes were synthesized to mimic the presence of their major mineral components, including metal oxides, calcium, and sulfur. The results of this study led to the conclusion that the presence of sulfates limits formation of EPFRs due to inhibition or poisoning of the transition metal active sites necessary for their formation. These findings provide a pathway toward understanding differences in EPFR presence on particulate matter and uncover the possibility of remediating EPFRs from incineration and hazardous waste sites.
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Affiliation(s)
- Elisabeth E. Feld-Cook
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Lisa Bovenkamp-Langlois
- Center for Advanced Microstructures & Devices (CAMD), Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Slawo M. Lomnicki
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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Yan L, Song J, Chan T, Jing C. Insights into Antimony Adsorption on {001} TiO 2: XAFS and DFT Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6335-6341. [PMID: 28513146 DOI: 10.1021/acs.est.7b00807] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Antimony (Sb) contamination poses an emerging environmental risk, whereas its removal remains a contemporary challenge due to the lack of knowledge in its surface chemistry and efficient adsorbent. In this study, self-assembly {001} TiO2 was examined for its effectiveness in Sb removal, and the molecular level surface chemistry was studied with X-ray absorption spectroscopy and density functional theory calculations. The kinetics results show that Sb adsorption followed the pseudo-second order reaction, and the Langmuir adsorption capacity was 200 mg/g for Sb(III) and 156 mg/g for Sb(V). The PZC of TiO2, which was 6.6 prior to the adsorption experiment, shifted to 4.8 and <0 after adsorption of Sb(III) and Sb(V), respectively, indicating the formation of negatively charged inner-sphere complexes. EXAFS results suggest that Sb(III/V) adsorption exhibited a bidentate binuclear surface complex. The orbital hybridizing of complexes was studied by XANES, molecular orbital theory (MO), and density of states (DOS) calculations. The change in orbital energy derived from orbital hybridizing of adsorbed Sb on surfaces is the driving force underlining the Sb surface chemistry. New bonds between Sb and TiO2 surface were formed with matched orbital energies. Integrating the molecular and electronic structures into surface complexation modeling reveals the nature of macroscopic Sb adsorption behaviors.
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Affiliation(s)
- Li Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Jiaying Song
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
| | - Tingshan Chan
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - Chuanyong Jing
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
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Electronic State of Sodium trans-[Tetrachloridobis(1H-indazole)ruthenate(III)] (NKP-1339) in Tumor, Liver and Kidney Tissue of a SW480-bearing Mouse. Sci Rep 2017; 7:40966. [PMID: 28112202 PMCID: PMC5256101 DOI: 10.1038/srep40966] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/13/2016] [Indexed: 12/19/2022] Open
Abstract
Ruthenium complexes are promising candidates for anticancer agents, especially NKP-1339 (sodium trans-[tetrachloridobis(1H-indazole)ruthenate(III)]), which is on the edge to clinical applications. The anticancer mechanism seems to be tightly linked to the redox chemistry but despite progress in human clinical trials the in vivo Ru oxidation state and the coordination of Ru remains unclear. The Ru-based anticancer drug NKP-1339 was studied applying XANES (Cl K- and Ru L2,3-edges) in tumor, kidney and liver tissue of a SW480 bearing mouse. Based on coordination charge and 3D XANES plots containing a series of model compounds as well as pre-edge analysis of the ligand Cl K-edge it is suggested that NKP-1339 remains in its +III oxidation state after 24 hours and at least one of the four chlorido ligands remain covalently bound to the Ru ion showing a biotransformation from RuIIIN2Cl4 to RuIIIClx(N/O)6−x (X = 1 or 2).
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Jijil CP, Lokanathan M, Chithiravel S, Nayak C, Bhattacharyya D, Jha SN, Babu PD, Kakade B, Devi RN. Nitrogen Doping in Oxygen-Deficient Ca 2Fe 2O 5: A Strategy for Efficient Oxygen Reduction Oxide Catalysts. ACS APPLIED MATERIALS & INTERFACES 2016; 8:34387-34395. [PMID: 27998122 DOI: 10.1021/acsami.6b11718] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Oxygen reduction reaction (ORR) is increasingly being studied in oxide systems due to advantages ranging from cost effectiveness to desirable kinetics. Oxygen-deficient oxides like brownmillerites are known to enhance ORR activity by providing oxygen adsorption sites. In parallel, nitrogen and iron doping in carbon materials, and consequent presence of catalytically active complex species like C-Fe-N, is also suggested to be good strategies for designing ORR-active catalysts. A combination of these features in N-doped Fe containing brownmillerite can be envisaged to present synergistic effects to improve the activity. This is conceptualized in this report through enhanced activity of N-doped Ca2Fe2O5 brownmillerite when compared to its oxide parents. N doping is demonstrated by neutron diffraction, UV-vis spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. Electrical conductivity is also found to be enhanced by N doping, which influences the activity. Electrochemical characterization by cyclic voltammetry, rotating disc electrode, and rotating ring disk electrode (RRDE) indicates an improved oxygen reduction activity in N-doped brownmillerite, with a 10 mV positive shift in the onset potential. RRDE measurements show that the compound exhibits 4-electron reduction pathways with lower H2O2 production in the N-doped system; also, the N-doped sample exhibited better stability. The observations will enable better design of ORR catalysts that are stable and cost-effective.
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Affiliation(s)
| | | | | | | | | | | | | | | | - R Nandini Devi
- Academy of Scientific and Innovative Research, New Delhi, India
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Xu T, Catalano JG. Impacts of Surface Site Coordination on Arsenate Adsorption: Macroscopic Uptake and Binding Mechanisms on Aluminum Hydroxide Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:13261-13269. [PMID: 27951685 DOI: 10.1021/acs.langmuir.6b03214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aluminum hydroxides play important roles in regulating the fate and transport of contaminants and nutrients in soils and aquatic systems. Like many metal oxides, these minerals display surface functional groups in a series of coordination states, each of which may differ in its affinity for adsorbates. The distribution of functional group types varies among distinct surfaces of aluminum hydroxides, and we thus hypothesize that the adsorption behavior and mechanisms will show a dependence on particle morphology. To test this hypothesis, we investigate arsenate adsorption on two aluminum hydroxide polymorphs with distinct particle morphologies, gibbsite [γ-Al(OH)3] and bayerite [α-Al(OH)3], at pH 4 and 7. Synthetic gibbsite platelets expose large (001) basal surfaces predicted to be terminated by doubly coordinated functional groups (>Al2OH). In contrast, synthetic bayerite microrods display mainly edge surfaces (parallel to the c axis) containing abundant singly coordinated functional groups (>AlOH2). Macroscopic adsorption studies show that gibbsite adsorbs less arsenate per unit surface area than bayerite at both pH values and suggest that two surface complexes form on each material. Similar electrokinetic behavior is displayed at the same relative coverages of arsenate, suggesting that similar reactive surface groups (>AlOH2) control the surface charging on both particles. EXAFS spectroscopy shows that there is no variation in arsenate surface speciation on a given mineral with surface coverage or pH. Whereas bidentate binuclear inner-sphere species are the dominant complexes present, the EXAFS result suggest that outer-sphere species also occur on both minerals, with a greater abundance on gibbsite. This binding mode likely involves adsorption to >Al2OH sites, which have a slow ligand exchange rate that inhibits inner-sphere binding. These results demonstrate that adsorption mechanisms and capacity, even when normalized for specific surface area, vary with metal oxide particle morphology because of the distribution of distinct functional groups.
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Affiliation(s)
- Tingying Xu
- Department of Earth and Planetary Sciences, Washington University , 1 Brookings Drive, Saint Louis, Missouri 63130, United States
| | - Jeffrey G Catalano
- Department of Earth and Planetary Sciences, Washington University , 1 Brookings Drive, Saint Louis, Missouri 63130, United States
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Chen KY, Chen TY, Chan YT, Cheng CY, Tzou YM, Liu YT, Teah HY. Stabilization of Natural Organic Matter by Short-Range-Order Iron Hydroxides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:12612-12620. [PMID: 27782386 DOI: 10.1021/acs.est.6b02793] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dissolved organic matter (DOM) is capable of modifying the surfaces of soil minerals (e.g., Fe hydroxides) or even forming stable co-precipitates with Fe(III) in a neutral environment. The DOM/Fe co-precipitation may alter biogeochemical carbon cycling in soils if the relatively mobile DOM is sorbed by soil minerals against leaching, runoff, and biodegradation. In this study, we aimed to determine the structural development of DOM/Fe co-precipitates in relation to changes in pH and C/(C + Fe) ratios using XRD, XPS, Fe K-edge XAS, FTIR, and C-NEXAFS techniques. The results showed that in the system with bulk C/(C + Fe) molar ratios ≤0.65, the ferrihydrite-like Fe domains were precipitated as the core and covered by the C shells. When the C/(C + Fe) molar ratio ranged between 0.71 and 0.89, the emerging Fe-C bonding suggested a more substantial association between Fe domains including edge- and corner-sharing FeO6 octahedra and DOM. With C/(C + Fe) bulk molar ratios ≥0.92, only corner-sharing FeO6 octahedra along with Fe-C bonding were found. The homogeneously distributed C and Fe domains caused the enhancement of Fe and C solubilization from co-precipitates. The C/(C + Fe) ratios dominated structural compositions and stabilities of C/Fe co-precipitates and may directly affect the Fe and C cycles in soils.
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Affiliation(s)
- Kai-Yue Chen
- Department of Soil and Environmental Sciences, National Chung Hsing University , Taichung 40227, Taiwan, R.O.C
| | - Tsan-Yao Chen
- Department of Engineering and System Sciences, National Tsing Hua University , Hsinchu 30043, Taiwan, R.O.C
| | - Ya-Ting Chan
- Department of Soil and Environmental Sciences, National Chung Hsing University , Taichung 40227, Taiwan, R.O.C
| | - Ching-Yun Cheng
- Department of Soil and Environmental Sciences, National Chung Hsing University , Taichung 40227, Taiwan, R.O.C
| | - Yu-Min Tzou
- Department of Soil and Environmental Sciences, National Chung Hsing University , Taichung 40227, Taiwan, R.O.C
| | - Yu-Ting Liu
- Department of Soil and Environmental Sciences, National Chung Hsing University , Taichung 40227, Taiwan, R.O.C
| | - Heng-Yi Teah
- Division of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo , 332 Building of Environmental Studies, 5-1-5 Kashiwanoha, Kashiwa City, Chiba 277-8563, Japan
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Santos WO, Hesterberg D, Mattiello EM, Vergütz L, Barreto MSC, Silva IR, Souza Filho LFS. Increasing Soluble Phosphate Species by Treatment of Phosphate Rocks with Acidic Waste. JOURNAL OF ENVIRONMENTAL QUALITY 2016; 45:1988-1997. [PMID: 27898793 DOI: 10.2134/jeq2016.03.0079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The development of efficient fertilizers with a diminished environmental footprint will help meet the increasing demand for food and nutrients by a growing global population. Our objective was to evaluate whether an acidic mine waste (AMW) could be used beneficially by reacting it with sparingly soluble phosphate rocks (PRs) to produce more soluble P fertilizer materials. Three PRs from Brazil and Peru were reacted with different concentrations of AMW. Changes in mineralogy and P species were determined using a combination of X-ray diffraction and phosphorus K-edge XANES spectroscopy, in addition to extractable P concentrations. Increasing the AMW concentration typically increased extractable P. X-ray diffraction data showed transformation of apatite to other species when PRs were reacted with AMW at ≥50% (v/v) in water, with gypsum or anhydrite forming at AMW concentrations as low as 12.5%. Linear combination fitting analysis of X-ray absorption near edge structure spectra also indicated a progressive transformation of apatite to noncrystalline Fe(III)-phosphate and more soluble Ca-phosphates with increasing AMW concentration. Because this AMW is costly to dispose of, reacting it with PR to produce a higher-grade phosphate fertilizer material could decrease the environmental impacts of the AMW and diminish the consumption of pure acids in conventional P fertilizer production.
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Gillispie EC, Austin RE, Rivera NA, Bolich R, Duckworth OW, Bradley P, Amoozegar A, Hesterberg D, Polizzotto ML. Soil Weathering as an Engine for Manganese Contamination of Well Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9963-9971. [PMID: 27570123 DOI: 10.1021/acs.est.6b01686] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Manganese (Mn) contamination of well water is recognized as an environmental health concern. In the southeastern Piedmont region of the United States, well water Mn concentrations can be >2 orders of magnitude above health limits, but the specific sources and causes of elevated Mn in groundwater are generally unknown. Here, using field, laboratory, spectroscopic, and geospatial analyses, we propose that natural pedogenetic and hydrogeochemical processes couple to export Mn from the near-surface to fractured-bedrock aquifers within the Piedmont. Dissolved Mn concentrations are greatest just below the water table and decrease with depth. Solid-phase concentration, chemical extraction, and X-ray absorption spectroscopy data show that secondary Mn oxides accumulate near the water table within the chemically weathering saprolite, whereas less-reactive, primary Mn-bearing minerals dominate Mn speciation within the physically weathered transition zone and bedrock. Mass-balance calculations indicate soil weathering has depleted over 40% of the original solid-phase Mn from the near-surface, and hydrologic gradients provide a driving force for downward delivery of Mn. Overall, we estimate that >1 million people in the southeastern Piedmont consume well water containing Mn at concentrations exceeding recommended standards, and collectively, these results suggest that integrated soil-bedrock-system analyses are needed to predict and manage Mn in drinking-water wells.
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Affiliation(s)
- Elizabeth C Gillispie
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Robert E Austin
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Nelson A Rivera
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Rick Bolich
- North Carolina Department of Environmental Quality - Division of Water Resources, 3800 Barrett Drive, Raleigh, North Carolina 27609, United States
| | - Owen W Duckworth
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Phil Bradley
- Norh Carolina Geological Survey, 512 North Salisbury Street, Raleigh, North Carolina 27604, United States
| | - Aziz Amoozegar
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Dean Hesterberg
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
| | - Matthew L Polizzotto
- Department of Crop and Soil Sciences, North Carolina State University , 101 Derieux St, Campus Box 7619, Raleigh, North Carolina 26795, United States
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Alford ÉR, Lindblom SD, Pittarello M, Freeman JL, Fakra SC, Marcus MA, Broeckling C, Pilon-Smits EAH, Paschke MW. Roles of rhizobial symbionts in selenium hyperaccumulation in Astragalus (Fabaceae). AMERICAN JOURNAL OF BOTANY 2014; 101:1895-905. [PMID: 25366855 DOI: 10.3732/ajb.1400223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
PREMISE OF THE STUDY Are there dimensions of symbiotic root interactions that are overlooked because plant mineral nutrition is the foundation and, perhaps too often, the sole explanation through which we view these relationships? In this paper we investigate how the root nodule symbiosis in selenium (Se) hyperaccumulator and nonaccumulator Astragalus species influences plant selenium (Se) accumulation. METHODS In greenhouse studies, Se was added to nodulated and nonnodulated hyperaccumulator and nonaccumulator Astragalus plants, followed by investigation of nitrogen (N)-Se relationships. Selenium speciation was also investigated, using x-ray microprobe analysis and liquid chromatography-mass spectrometry (LC-MS). KEY RESULTS Nodulation enhanced biomass production and Se to S ratio in both hyperaccumulator and nonaccumulator plants. The hyperaccumulator contained more Se when nodulated, while the nonaccumulator contained less S when nodulated. Shoot [Se] was positively correlated with shoot N in Se-hyperaccumulator species, but not in nonhyperaccumulator species. The x-ray microprobe analysis showed that hyperaccumulators contain significantly higher amounts of organic Se than nonhyperaccumulators. LC-MS of A. bisulcatus leaves revealed that nodulated plants contained more γ-glutamyl-methylselenocysteine (γ-Glu-MeSeCys) than nonnodulated plants, while MeSeCys levels were similar. CONCLUSIONS Root nodule mutualism positively affects Se hyperaccumulation in Astragalus. The microbial N supply particularly appears to contribute glutamate for the formation of γ-Glu-MeSeCys. Our results provide insight into the significance of symbiotic interactions in plant adaptation to edaphic conditions. Specifically, our findings illustrate that the importance of these relationships are not limited to alleviating macronutrient deficiencies.
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Affiliation(s)
- Élan R Alford
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523 USA Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, Colorado 80523 USA
| | - Stormy D Lindblom
- Biology Department, Colorado State University, Fort Collins, Colorado 80523 USA
| | - Marco Pittarello
- Biology Department, Colorado State University, Fort Collins, Colorado 80523 USA
| | - John L Freeman
- Biology Department, Colorado State University, Fort Collins, Colorado 80523 USA
| | - Sirine C Fakra
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA
| | - Matthew A Marcus
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA
| | - Corey Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, Colorado 80523 USA
| | - Elizabeth A H Pilon-Smits
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523 USA Biology Department, Colorado State University, Fort Collins, Colorado 80523 USA
| | - Mark W Paschke
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523 USA Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, Colorado 80523 USA
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Ping Y, Hicks DG, Yaakobi B, Coppari F, Eggert J, Collins GW. A platform for x-ray absorption fine structure study of dynamically compressed materials above 1 Mbar. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:123105. [PMID: 24387418 DOI: 10.1063/1.4841935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A platform consisting of a multi-shock drive and an implosion backlighter has been developed for x-ray absorption fine structure (XAFS) measurements on materials compressed to multi-Mbar pressures. The experimental setup, target design, and backlighter characteristics are presented. Extended XAFS (EXAFS) measurements for various materials have been demonstrated. A quintuple-crystal design is described to enhance the efficiency of the x-ray spectrometer, enabling observation of very weak EXAFS signals in a single shot.
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Affiliation(s)
- Y Ping
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D G Hicks
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - B Yaakobi
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - F Coppari
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Eggert
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G W Collins
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Abstract
The in situ stimulation of Fe(III) oxide reduction in the subsurface stimulates the growth of Geobacter spp. and the precipitation of U(VI) from groundwater. As with Fe(III) oxide reduction, the reduction of uranium by Geobacter spp. requires the expression of their conductive pili. The pili bind the soluble uranium and catalyse its extracellular reductive precipitation along the pili filaments as a mononuclear U(IV) complexed by carbon-containing ligands. Although most of the uranium is immobilized by the pili, some uranium deposits are also observed in discreet regions of the outer membrane, consistent with the participation of redox-active foci, presumably c-type cytochromes, in the extracellular reduction of uranium. It is unlikely that cytochromes released from the outer membrane could associate with the pili and contribute to the catalysis, because scanning tunnelling microscopy spectroscopy did not reveal any haem-specific electronic features in the pili, but, rather, showed topographic and electronic features intrinsic to the pilus shaft. Pili not only enhance the rate and extent of uranium reduction per cell, but also prevent the uranium from traversing the outer membrane and mineralizing the cell envelope. As a result, pili expression preserves the essential respiratory activities of the cell envelope and the cell's viability. Hence the results support a model in which the conductive pili function as the primary mechanism for the reduction of uranium and cellular protection in Geobacter spp.
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Pokrovsky OS, Pokrovski GS, Shirokova LS, Gonzalez AG, Emnova EE, Feurtet-Mazel A. Chemical and structural status of copper associated with oxygenic and anoxygenic phototrophs and heterotrophs: possible evolutionary consequences. GEOBIOLOGY 2012; 10:130-149. [PMID: 22039921 DOI: 10.1111/j.1472-4669.2011.00303.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Copper adsorption on the surface and intracellular uptake inside the cells of four representative taxons of soil and aquatic micro-organisms: aerobic rhizospheric heterotrophs (Pseudomonas aureofaciens), anoxygenic (Rhodovulum steppense) and oxygenic (cyanobacteria Gloeocapsa sp. and freshwater diatoms Navicula minima) phototrophs were studied in a wide range of pH, copper concentration, and time of exposure. Chemical status of adsorbed and assimilated Cu was investigated using in situ X-ray absorption spectroscopy. In case of adsorbed copper, XANES spectra demonstrated significant fractions of Cu(I) likely in the form of tri-coordinate complexes with O/N and/or S ligands. Upon short-term reversible adsorption at all four studied micro-organisms' cell surface, Cu(II) is coordinated by 4.0 ± 0.5 planar oxygens at an average distance of 1.97 ± 0.02 Å, which is tentatively assigned to the carboxylate groups. The atomic environment of copper incorporated into diatoms and cyanobacteria during long-term growth is similar to that of the adsorbed metal with slightly shorter distances to the first O/N neighbor (1.95 Å). In contrast to the common view of Cu status in phototrophic micro-organisms, XAFS failed to detect sulfur in the nearest atomic environment of Cu assimilated by freshwater plankton (cyanobacteria) and periphyton (diatoms). The appearance of S in Cu 1st coordination shell at 2.27-2.32 Å was revealed only after long-term interaction of Cu with anoxygenic phototrophs (and Cu uptake by soil heterotrophs), suggesting Cu scavenging in the form of sulfhydryl, histidine/carboxyl or a mixture of carboxylate and sulfhydryl complexes. These new structural constraints suggest that adsorbed Cu(II) is partially reduced to Cu(I) already at the cell surface, where as intracellular Cu uptake and storage occur in the form of both Cu(I)-S linked proteins and Cu(II) carboxylates. Obtained results allow to better understand how, in the course of biological evolution, micro-organisms elaborated various mechanisms of Cu uptake and storage, from passive adsorption and uptake to active, protein-controlled surface reduction, and intracellular storage.
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Affiliation(s)
- O S Pokrovsky
- Géosciences Environnement Toulouse (GET), Université de Toulouse, Toulouse, France.
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Quinn CF, Prins CN, Freeman JL, Gross AM, Hantzis LJ, Reynolds RJB, Yang SI, Covey PA, Bañuelos GS, Pickering IJ, Fakra SC, Marcus MA, Arathi HS, Pilon-Smits EAH. Selenium accumulation in flowers and its effects on pollination. THE NEW PHYTOLOGIST 2011; 192:727-37. [PMID: 21793829 DOI: 10.1111/j.1469-8137.2011.03832.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
• Selenium (Se) hyperaccumulation has a profound effect on plant-arthropod interactions. Here, we investigated floral Se distribution and speciation in flowers and the effects of floral Se on pollen quality and plant-pollinator interactions. • Floral Se distribution and speciation were compared in Stanleya pinnata, an Se hyperaccumulator, and Brassica juncea, a comparable nonhyperaccumulator. Pollen germination was measured from plants grown with varying concentrations of Se and floral visitation was compared between plants with high and low Se. • Stanleya pinnata preferentially allocated Se to flowers, as nontoxic methyl-selenocysteine (MeSeCys). Brassica juncea had higher Se concentrations in leaves than flowers, and a lower fraction of MeSeCys. For B. juncea, high floral Se concentration impaired pollen germination; in S. pinnata Se had no effect on pollen germination. Floral visitors collected from Se-rich S. pinnata contained up to 270 μg g(-1), concentrations toxic to many herbivores. Indeed, floral visitors showed no visitation preference between high- and low-Se plants. Honey from seleniferous areas contained 0.4-1 μg Se g(-1), concentrations that could provide human health benefits. • This study is the first to shed light on the possible evolutionary cost, through decreased pollen germination in B. juncea, of Se accumulation and has implications for the management of seleniferous areas.
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Affiliation(s)
- Colin F Quinn
- Department of Biology, Colorado State University, Fort Collins, CO 80532, USA
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