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Paineau E, Bourdelle F, Bhandary R, Truche L, Lorgeoux C, Bacia-Verloop M, Monet G, Rouzière S, Vantelon D, Briois V, Launois P. Nonclassical Growth Mechanism of Double-Walled Metal-Oxide Nanotubes Implying Transient Single-Walled Structures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2308665. [PMID: 38229562 DOI: 10.1002/smll.202308665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/01/2023] [Indexed: 01/18/2024]
Abstract
The formation of imogolite nanotubes is reported to be a kinetic process involving intermediate roof-tile nanostructures. Here, the structural evolution occurring during the synthesis of aluminogermanate double-walled imogolite nanotubes is in situ monitored, thanks to an instrumented autoclave allowing the control of the temperature, the continuous measurement of pH and pressure, and the regular sampling of gas and solution. Chemical analyses confirm the completion of the precursor's conversion with the release of CO2, ethanol, and dioxane as main side products. The combination of microscopic observations, infrared, and absorption spectroscopies with small and wide-angle X-ray scattering experiments unravel a unique growth mechanism implying transient single-walled nanotubes instead of the self-assembly of stacked proto-imogolite tiles. The growth formation of these transient nanotubes is followed at the molecular level by Quick-X-ray absoprtion specotrscopy experiments. Multivariate data analysis evidences that the near neighboring atomic environment of Ge evolves from monotonous to a more complex one as the reaction progresses. The following transformation into a double-walled nanotube takes place at a nearly constant mean radius, as demonstrated by the simulation of X-ray scattering diagrams. Overall, transient nanotubes appear to serve for the anchoring of a new wall, corresponding to a mechanism radically different from that proposed in the literature.
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Affiliation(s)
- Erwan Paineau
- CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay, 91405, France
| | - Franck Bourdelle
- GEC Laboratoire Géosciences & Environnement Cergy, CY Cergy Paris Université, Neuville-sur-Oise, 95000, France
| | - Rajesh Bhandary
- CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay, 91405, France
- Macromolecular Chemistry, Division of Technical and Macromolecular Chemistry, Institute of Chemistry, Faculty of Natural Science II (Chemistry, Physics and Mathematics), Martin Luther University Halle-Wittenberg, von-Danckelmann-Platz 4, D-06120, Halle, Germany
| | - Laurent Truche
- CNRS, ISTerre, University Grenoble Alpes, CS 40700, Grenoble, 38058, France
| | - Catherine Lorgeoux
- GeoRessources, UMR 7359 CNRS, Université de Lorraine, Campus Aiguillettes, Vandœuvre-lès-Nancy, 54506, France
| | - Maria Bacia-Verloop
- Institut de Biologie Structurale, CEA, CNRS, Université de Grenoble Alpes, Grenoble, 38027, France
| | - Geoffrey Monet
- CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay, 91405, France
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, F-75005, France
| | - Stéphan Rouzière
- CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay, 91405, France
| | - Delphine Vantelon
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, Cedex, 91192, France
| | - Valérie Briois
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, Cedex, 91192, France
| | - Pascale Launois
- CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay, 91405, France
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Paineau E, Teobaldi G, Jiménez‐Calvo P. Imogolite Nanotubes and Their Permanently Polarized Bifunctional Surfaces for Photocatalytic Hydrogen Production. GLOBAL CHALLENGES (HOBOKEN, NJ) 2024; 8:2300255. [PMID: 38868604 PMCID: PMC11165560 DOI: 10.1002/gch2.202300255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/17/2023] [Indexed: 06/14/2024]
Abstract
To date, imogolite nanotubes (INTs) have been primarily used for environmental applications such as dye and pollutant degradation. However, imogolite's well-defined porous structure and distinctive electro-optical properties have prompted interest in the system's potential for energy-relevant chemical reactions. The imogolite structure leads to a permanent intrawall polarization arising from the presence of bifunctional surfaces at the inner and outer tube walls. Density functional theory simulations suggest such bifunctionality to encompass also spatially separated band edges. Altogether, these elements make INTs appealing candidates for facilitating chemical conversion reactions. Despite their potential, the exploitation of imogolite's features for photocatalysis is at its infancy, thence relatively unexplored. This perspective overviews the basic physical-chemical and optoelectronical properties of imogolite nanotubes, emphasizing their role as wide bandgap insulator. Imogolite nanotubes have multifaceted properties that could lead to beneficial outcomes in energy-related applications. This work illustrates two case studies demonstrating a step-forward on photocatalytic hydrogen production achieved through atomic doping or metal co-catalyst. INTs exhibit potential in energy conversion and storage, due to their ability to accommodate functions such as enhancing charge separation and influencing the chemical potentials of interacting species. Yet, tapping into potential for energy-relevant application needs further experimental research, computational, and theoretical analysis.
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Affiliation(s)
- Erwan Paineau
- CNRSLaboratoire de Physique des SolidesUniversité Paris‐SaclayOrsay91405France
| | - Gilberto Teobaldi
- Scientific Computing DepartmentSTFC UKRIRutherford Appleton LaboratoryHarwell CampusDidcotOX11 0QXUK
| | - Pablo Jiménez‐Calvo
- Chair of Thin Film MaterialsIZNFFriedrich‐Alexander‐ Universität Erlangen‐NürnbergCauerstraße 391058ErlangenGermany
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Qiu Z, Chen J, Zeng J, Dai R, Wang Z. A review on artificial water channels incorporated polyamide membranes for water purification: Transport mechanisms and performance. WATER RESEARCH 2023; 247:120774. [PMID: 37898000 DOI: 10.1016/j.watres.2023.120774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 10/30/2023]
Abstract
While thin-film composite (TFC) polyamide (PA) membranes are advanced for removing salts and trace organic contaminants (TrOCs) from water, TFC PA membranes encounter a water permeance-selectivity trade-off due to PA layer structural characteristics. Drawing inspiration from the excellent water permeance and solute rejection of natural biological channels, the development of analogous artificial water channels (AWCs) in TFC PA membranes (abbreviated as AWCM) promises to achieve superior mass transfer efficiency, enabling breaking the upper bound of water permeance and selectivity. Herein, we first discussed the types and structural characteristics of AWCs, followed by summarizing the methods for constructing AWCM. We discussed whether the AWCs acted as the primary mass transfer channels in AWCM and emphasized the important role of the AWCs in water transport and ion/TrOCs rejection. We thoroughly summarized the molecular-level mechanisms and structure-performance relationship of water molecules, ions, and TrOCs transport in the confined nanospace of AWCs, which laid the foundation for illustrating the enhanced water permeance and salt/TrOCs selectivity of AWCM. Finally, we discussed the challenges encountered in the field of AWCM and proposed future perspectives for practical applications. This review is expected to offer guidance for understanding the transport mechanisms of AWCM and developing next-generation membrane for effective water treatment.
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Affiliation(s)
- Zhiwei Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Jiansuxuan Chen
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Jin Zeng
- School of Software Engineering, Tongji University, Shanghai 201804, PR China
| | - Ruobin Dai
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
| | - Zhiwei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
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Zou Y, Hu Y, Shen Z, Yao L, Tang D, Zhang S, Wang S, Hu B, Zhao G, Wang X. Application of aluminosilicate clay mineral-based composites in photocatalysis. J Environ Sci (China) 2022; 115:190-214. [PMID: 34969448 DOI: 10.1016/j.jes.2021.07.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/08/2021] [Accepted: 07/15/2021] [Indexed: 05/18/2023]
Abstract
Aluminosilicate clay mineral (ACM) is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring. In past two decades, in-depth understanding on unique layered structure and abundant surface properties endows ACM in the emerging research and application fields. In field of solar-chemical energy conversion, ACM has been widely used to support various semiconductor photocatalysts, forming the composites and achieving efficient conversion of reactants under sunlight irradiation. To date, classic ACM such as kaolinite and montmorillonite, loaded with semiconductor photocatalysts has been widely applied in photocatalysis. This review summaries the recent works on ACM-based composites in photocatalysis. Focusing on the properties of surface and layered structure, we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM, i.e., type 1:1 and type 2:1. Not only large surface area and active surface hydroxyl group assist the substrate adsorption, but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts. Besides, we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process. This review could inspire more upcoming design and synthesis for ACM-based photocatalysts, leading this kind of economic and eco-friendly materials for more practical application in the future.
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Affiliation(s)
- Yingtong Zou
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; School of Life Science, Shaoxing University, Shaoxing 312000, China
| | - Yezi Hu
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Zewen Shen
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Ling Yao
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Duoyue Tang
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Sai Zhang
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Shuqin Wang
- School of Life Science, Shaoxing University, Shaoxing 312000, China
| | - Baowei Hu
- School of Life Science, Shaoxing University, Shaoxing 312000, China
| | - Guixia Zhao
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; School of Life Science, Shaoxing University, Shaoxing 312000, China.
| | - Xiangke Wang
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; School of Life Science, Shaoxing University, Shaoxing 312000, China.
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Hamon C, Beaudoin E, Launois P, Paineau E. Doping Liquid Crystals of Colloidal Inorganic Nanotubes by Additive-Free Metal Nanoparticles. J Phys Chem Lett 2021; 12:5052-5058. [PMID: 34019414 DOI: 10.1021/acs.jpclett.1c01311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Doping liquid-crystal phases with nanoparticles is a fast-growing field with potential breakthroughs due to the combination of the properties brought by the two components. One of the main challenges remains the long-term stability of the hybrid system, requiring complex functionalization of the nanoparticles at the expense of their self-assembly properties. Here we demonstrate the successful synthesis of additive-free noble-metal nanoparticles at the surface of charged inorganic nanotubes. Transmission electron microscopy and UV-visible spectroscopy confirm the stabilization of metallic nanoparticles on nanotubes. Meanwhile, the spontaneous formation of liquid-crystals phases induced by the nanotubes is observed, even after surface modification with metallic nanoparticles. Small-angle X-ray scattering experiments reveal that the average interparticle distance in the resulting hybrids can be easily modulated by controlling electrostatic interactions. As a proof-of-concept, we demonstrate the effectiveness of our method for the preparation of homogeneous transparent hybrid films with a high degree of alignment.
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Affiliation(s)
- Cyrille Hamon
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Emmanuel Beaudoin
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Pascale Launois
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Erwan Paineau
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
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Lenhardt KR, Breitzke H, Buntkowsky G, Reimhult E, Willinger M, Rennert T. Synthesis of short-range ordered aluminosilicates at ambient conditions. Sci Rep 2021; 11:4207. [PMID: 33603053 PMCID: PMC7892816 DOI: 10.1038/s41598-021-83643-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/04/2021] [Indexed: 01/31/2023] Open
Abstract
We report here on structure-related aggregation effects of short-range ordered aluminosilicates (SROAS) that have to be considered in the development of synthesis protocols and may be relevant for the properties of SROAS in the environment. We synthesized SROAS of variable composition by neutralizing aqueous aluminium chloride with sodium orthosilicate at ambient temperature and pressure. We determined elemental composition, visualized morphology by microscopic techniques, and resolved mineral structure by solid-state 29Si and 27Al nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Nitrogen sorption revealed substantial surface loss of Al-rich SROAS that resembled proto-imogolite formed in soils and sediments due to aggregation upon freezing. The effect was less pronounced in Si-rich SROAS, indicating a structure-dependent effect on spatial arrangement of mass at the submicron scale. Cryomilling efficiently fractured aggregates but did not change the magnitude of specific surface area. Since accessibility of surface functional groups is a prerequisite for sequestration of substances, elucidating physical and chemical processes of aggregation as a function of composition and crystallinity may improve our understanding of the reactivity of SROAS in the environment.
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Affiliation(s)
- Katharina R. Lenhardt
- grid.9464.f0000 0001 2290 1502Fachgebiet Bodenchemie mit Pedologie, Institut für Bodenkunde und Standortslehre, Universität Hohenheim, Emil-Wolff-Str. 27, 70599 Stuttgart, Germany
| | - Hergen Breitzke
- grid.6546.10000 0001 0940 1669Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, 64287 Darmstadt, Germany
| | - Gerd Buntkowsky
- grid.6546.10000 0001 0940 1669Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, 64287 Darmstadt, Germany
| | - Erik Reimhult
- grid.5173.00000 0001 2298 5320Institut für Biologisch Inspirierte Materialien, Universität für Bodenkultur Wien, Muthgasse 11/II, 1190 Wien, Austria
| | - Max Willinger
- grid.5173.00000 0001 2298 5320Institut für Biologisch Inspirierte Materialien, Universität für Bodenkultur Wien, Muthgasse 11/II, 1190 Wien, Austria
| | - Thilo Rennert
- grid.9464.f0000 0001 2290 1502Fachgebiet Bodenchemie mit Pedologie, Institut für Bodenkunde und Standortslehre, Universität Hohenheim, Emil-Wolff-Str. 27, 70599 Stuttgart, Germany
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7
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Pignié MC, Shcherbakov V, Charpentier T, Moskura M, Carteret C, Denisov S, Mostafavi M, Thill A, Le Caër S. Confined water radiolysis in aluminosilicate nanotubes: the importance of charge separation effects. NANOSCALE 2021; 13:3092-3105. [PMID: 33522536 DOI: 10.1039/d0nr08948f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Imogolite nanotubes are potentially promising co-photocatalysts because they are predicted to have curvature-induced, efficient electron-hole pair separation. This prediction has however not yet been experimentally proven. Here, we investigated the behavior upon irradiation of these inorganic nanotubes as a function of their water content to understand the fate of the generated electrons and holes. Two types of aluminosilicate nanotubes were studied: one was hydrophilic on its external and internal surfaces (IMO-OH) and the other had a hydrophobic internal cavity due to Si-CH3 bonds (IMO-CH3), with the external surface remaining hydrophilic. Picosecond pulse radiolysis experiments demonstrated that the electrons are efficiently driven outward. For imogolite samples with very few external water molecules (around 1% of the total mass), quasi-free electrons were formed. They were able to attach to a water molecule, generating a water radical anion, which ultimately led to dihydrogen. When more external water molecules were present, solvated electrons, precursors of dihydrogen, were formed. In contrast, holes moved towards the internal surface of the tubes. They mainly led to the formation of dihydrogen and of methane in irradiated IMO-CH3. The attachment of the quasi-free electron to water was a very efficient process and accounted for the high dihydrogen production at low relative humidity values. When the water content increased, electron solvation dominated over attachment to water molecules. Electron solvation led to dihydrogen production, albeit to a lesser extent than quasi-free electrons. Our experiments demonstrated the spontaneous curvature-induced charge separation in these inorganic nanotubes, making them very interesting potential co-photocatalysts.
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Affiliation(s)
- Marie-Claire Pignié
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
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8
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Termination Effects in Aluminosilicate and Aluminogermanate Imogolite Nanotubes: A Density Functional Theory Study. CRYSTALS 2020. [DOI: 10.3390/cryst10111051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigate termination effects in aluminosilicate (AlSi) and aluminogermanate (AlGe) imogolite nanotubes (NTs) by means of semi-local and range-corrected hybrid Density Functional Theory (DFT) simulations. Following screening and identification of the smallest finite model capable of accommodating full relaxation of the NT terminations around an otherwise geometrically and electrostatically unperturbed core region, we quantify and discuss the effects of physical truncation on the structure, relative energy, electrostatics and electronic properties of differently terminated, finite-size models of the NTs. In addition to composition-dependent changes in the valence (VB) and conduction band (CB) edges and resultant band gap (BG), the DFT simulations uncover longitudinal band bending and separation in the finite AlSi and AlGe models. Depending on the given termination of the NTs, such longitudinal effects manifest in conjunction with the radial band separation typical of fully periodic AlSi and AlGe NTs. The strong composition dependence of the longitudinal and radial band bending in AlSi and AlGe NTs suggests different mechanisms for the generation, relaxation and separation of photo-generated holes in AlSi and AlGe NTs, inviting further research in the untapped potential of imogolite compositional and structural flexibility for photo-catalytic applications.
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Huang X, Kang W, Guo J, Wang L, Tang H, Li T, Yu G, Ran W, Hong J, Shen Q. Highly reactive nanomineral assembly in soil colloids: Implications for paddy soil carbon storage. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:134728. [PMID: 31759715 DOI: 10.1016/j.scitotenv.2019.134728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/24/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
Mineral availability for carbon (C) binding is a key regulator of soil C storage, yet little is known about the highly reactive nanomineral assembly in the paddy soil colloids. Here, using high-resolution transmission electron microscopy (HRTEM), solid-state 27Al and 29Si nuclear magnetic resonance (NMR) spectroscopy and X-ray photoelectron spectroscopy (XPS), we investigated the coordination nature of short-range-ordered (SRO) minerals in water-dispersible colloids that were isolated from the paddy soil under different six-year fertilization regimes. Our results showed that organic fertilization not only promoted the transformation of crystalline minerals to SRO phases in the bulk soils but also increased the concentrations of Fe, Al and Si in the soil colloids compared to chemical fertilization alone, and thus enhanced the accumulation of organic C in both the bulk soils and the soil colloids. The HRTEM images revealed that water-dispersible colloids in all soils, regardless of treatment, were composed of crystalline Fe nanominerals (with some Al/Si) and SRO-Al/Si nanominerals (with some Fe) associated with organic C. Furthermore, the combined results from the 27Al and 29Si NMR spectroscopy and XPS not only confirmed the presence of SRO-Al/Si nanoparticles as Si-rich allophane and phytolith but also demonstrated that organic fertilization promoted the transformation of aluminosilicates to SRO-Al/Si nanominerals in soil colloids. Together, these findings indicate that six-year organic fertilization promotes the formation of SRO minerals (e.g., ferrihydrite, Si-rich allophane and Fe-substituted allophane, as well as phytolith) in soils and modulates the assembly of organo-mineral complexes possibly by driving the biogeochemical cycles of Fe, Al, Si and specific organic ligands, thus contributing to the long-term storage of C in paddy soils.
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Affiliation(s)
- Xiaolei Huang
- College of Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China; National Experimental Teaching Demonstration Center for Agricultural Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China; Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenjing Kang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Junjie Guo
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Lei Wang
- Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; Scientific Observation and Experimental Station of Arable Land Conservation of Jiangsu Province, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Haiyan Tang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Tingliang Li
- College of Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China; National Experimental Teaching Demonstration Center for Agricultural Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China
| | - Guanghui Yu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wei Ran
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jianping Hong
- College of Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China; National Experimental Teaching Demonstration Center for Agricultural Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi 080301, China
| | - Qirong Shen
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waster Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
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10
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Becerra-Herrera M, Moraga SD, Cruz-Hernández P, Molinas R, Richter P, Caraballo MA. Detection and assignment of inorganic aqueous polymers relevant to environmental nanogeoscience by direct infusion electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2019; 54:495-506. [PMID: 30907977 DOI: 10.1002/jms.4356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/12/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Inorganic polymers in aqueous solutions are being proposed as essential components in new theories concerning nonclassical nucleation and growth of nanominerals relevant to environmental nanogeosciences. The study of those complex natural processes requires multi-technique analytical approaches able to characterize the solutions and their constituents (solutes, oligomers, polymers, clusters and nanominerals) from atomic to micrometric scales. A novel analytical approach involving an electrospray ionization source (ESI) coupled to time-of-flight mass spectrometry (TOF/MS) was developed to identify inorganic polymers in aqueous solution. To this end, the presence of initial Al oligomers and their polymerization processes was studied during a nanomineral aqueous synthesis (hydrobasaluminte, Al4 SO4 (OH)10 ·12-36H2 O). Ensuring the feasibility and robustness of the methodology as well as the stability of the polymers under study (avoiding undesirable fragmentation), a meticulous study of the ESI-TOF MS working conditions was performed. Precision of the methodology was evaluated obtaining relative standard deviations below 3.3%. For the first time in the study of inorganic polymers in the earth sciences, the mass accuracy error (ppm) has been reported and the use of significant decimal figures of the m/z signal has been taken into account. Complementary to this, a four-step polymer assignment methodology and a database with the Al- and Al-SO4 2- polymers assigned were created. Several polymers have been assigned for the first time, including Al (SO4 )+ ·H2 O, Al2 O(SO4 )2+ ·H2 O, Al5 O4 (OH)5 2+ ·2H2 O, and Al3 O5 (OH)2- ·4H2 O, among others. The results obtained in the present study help create a foundation to include mass spectrometry as a routine analytical technique to study mineral formation in aqueous solution.
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Affiliation(s)
| | | | | | | | - Pablo Richter
- Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile
| | - Manuel A Caraballo
- Department of Mining Engineering, University of Chile, Santiago, Chile
- AMTC, University of Chile, Santiago, Chile
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11
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Poli E, Elliott JD, Chulkov SK, Watkins MB, Teobaldi G. The Role of Cation-Vacancies for the Electronic and Optical Properties of Aluminosilicate Imogolite Nanotubes: A Non-local, Linear-Response TDDFT Study. Front Chem 2019; 7:210. [PMID: 31024896 PMCID: PMC6469436 DOI: 10.3389/fchem.2019.00210] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 03/18/2019] [Indexed: 11/13/2022] Open
Abstract
We report a combined non-local (PBE-TC-LRC) Density Functional Theory (DFT) and linear-response time-dependent DFT (LR-TDDFT) study of the structural, electronic, and optical properties of the cation-vacancy based defects in aluminosilicate (AlSi) imogolite nanotubes (Imo-NTs) that have been recently proposed on the basis of Nuclear Magnetic Resonance (NMR) experiments. Following numerical determination of the smallest AlSi Imo-NT model capable of accommodating the defect-induced relaxation with negligible finite-size errors, we analyse the defect-induced structural deformations in the NTs and ensuing changes in the NTs' electronic structure. The NMR-derived defects are found to introduce both shallow and deep occupied states in the pristine NTs' band gap (BG). These BG states are found to be highly localized at the defect site. No empty defect-state is modeled for any of the considered systems. LR-TDDFT simulation of the defects reveal increased low-energy optical absorbance for all but one defects, with the appearance of optically active excitations at energies lower than for the defect-free NT. These results enable interpretation of the low-energy tail in the experimental UV-vis spectra for AlSi NTs as being due to the defects. Finally, the PBE-TC-LRC-approximated exciton binding energy for the defects' optical transitions is found to be substantially lower (up to 0.8 eV) than for the pristine defect-free NT's excitations (1.1 eV).
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Affiliation(s)
- Emiliano Poli
- The Abdus Salam Center for Theoretical Physics, Condensed Matter and Statistical Physics Department, Trieste, Italy
| | - Joshua D. Elliott
- Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova, Padova, Italy
- CNR-IOM DEMOCRITOS, Consiglio Nazionale delle Ricerche-Istituto Officina dei Materiali, Trieste, Italy
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, United Kingdom
| | - Sergey K. Chulkov
- School of Mathematics and Physics, University of Lincoln, Brayford Pool, Lincoln, United Kingdom
| | - Matthew B. Watkins
- School of Mathematics and Physics, University of Lincoln, Brayford Pool, Lincoln, United Kingdom
| | - Gilberto Teobaldi
- Daresbury Laboratory, Scientific Computing Department, Science and Technology Facilities Council, Warrington, United Kingdom
- Beijing Computational Science Research Centre, Beijing, China
- Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
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12
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Lange T, Charpentier T, Gobeaux F, Charton S, Testard F, Thill A. Partial Transformation of Imogolite by Decylphosphonic Acid Yields an Interface Active Composite Material. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4068-4076. [PMID: 30793904 DOI: 10.1021/acs.langmuir.8b04242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The phosphonic acid moiety is commonly used as an anchoring group for the surface modification of imogolite. However, the impact of the reaction on its structure has never been clearly analyzed before. We study the reaction of imogolite and decylphosphonic acid by combining infrared spectroscopy, X-ray scattering, scanning electron microscopy, transmission electron microscopy, and solid-state nuclear magnetic resonance spectroscopy. Instead of a surface functionalization, we observe the formation of a lamellar phase interconnected with imogolite bundles. Although we find no evidence for grafted imogolite tubes, we observe the expected dispersion characteristics and stabilization of water in toluene emulsions described in the literature. Based on the surface chemistry of imogolite, we propose an explanation for the observed reactivity and link the structural features of the obtained composite material to its dispersibility in toluene and its observed properties at the toluene-water interface.
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Affiliation(s)
- Tobias Lange
- CEA, DEN, Research Department on Mining and Fuel Recycling Processes, SA2I , F-30207 Bagnols-sur-Cèze , France
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex , France
| | - Thibault Charpentier
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex , France
| | - Frédéric Gobeaux
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex , France
| | - Sophie Charton
- CEA, DEN, Research Department on Mining and Fuel Recycling Processes, SA2I , F-30207 Bagnols-sur-Cèze , France
| | - Fabienne Testard
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex , France
| | - Antoine Thill
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex , France
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González RI, Valencia FJ, Rogan J, Valdivia JA, Sofo J, Kiwi M, Munoz F. Bending energy of 2D materials: graphene, MoS 2 and imogolite. RSC Adv 2018; 8:4577-4583. [PMID: 35539543 PMCID: PMC9077804 DOI: 10.1039/c7ra10983k] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/15/2018] [Indexed: 11/21/2022] Open
Abstract
The bending process of 2D materials, subject to an external force, is investigated, and applied to graphene, molybdenum disulphide (MoS2), and imogolite. For graphene we obtained 3.43 eV Å2 per atom for the bending modulus, which is in good agreement with the literature. We found that MoS2 is ∼11 times harder to bend than graphene, and has a bandgap variation of ∼1 eV as a function of curvature. Finally, we also used this strategy to study aluminosilicate nanotubes (imogolite) which, in contrast to graphene and MoS2, present an energy minimum for a finite curvature radius. Roof tile shaped imogolite precursors turn out to be stable, and thus are expected to be created during imogolite synthesis, as predicted to occur by self-assembly theory.
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Affiliation(s)
- Rafael I González
- Centro de Nanotecnología Aplicada, Facultad de Ciencias, Universidad Mayor Santiago Chile
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
| | - Felipe J Valencia
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile Casilla 653 Santiago Chile
- Núcleo de Matemáticas, Física y Estadítica, Facultad de Ciencias, Universidad Mayor Manuel Montt 367, Providencia Santiago Chile
| | - José Rogan
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile Casilla 653 Santiago Chile
| | - Juan Alejandro Valdivia
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile Casilla 653 Santiago Chile
| | - Jorge Sofo
- Department of Physics and Material Research Institute, The Pennsylvania State University, University Park Pennsylvania 16802 USA
| | - Miguel Kiwi
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile Casilla 653 Santiago Chile
| | - Francisco Munoz
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA) Santiago Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile Casilla 653 Santiago Chile
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14
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Sun F, Li Y, Wang X, Chi Z, Yu G. Using new hetero-spectral two-dimensional correlation analyses and synchrotron-radiation-based spectromicroscopy to characterize binding of Cu to soil dissolved organic matter. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 223:457-465. [PMID: 28118997 DOI: 10.1016/j.envpol.2017.01.046] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/16/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Understanding the binding characteristics of copper (Cu) to different functional groups in soil dissolved organic matter (DOM) is important to explore Cu toxicity, bioavailability and ultimate fate in the environment. However, the methods used to explore such binding characteristics are still limited. Here, two-dimensional correlation spectroscopy (2DCOS) integrated with Fourier transform infrared (FTIR), 29Si nuclear magnetic resonance (NMR), 27Al NMR, and synchrotron-radiation-based FTIR spectromicroscopy were used to explore the binding characteristics of Cu to soil DOM as part of a long-term (23 years) fertilization experiment. Compared with no fertilization and inorganic fertilization (NPK), long-term pig manure fertilization (M) treatment significantly increased the concentration of total and bioavailable Cu in soils. Furthermore, hetero-spectral 2DCOS analyses demonstrated that the binding characteristics of Cu onto functional groups in soil DOM were modified by fertilization regimes. In the NPK treatment, Cu was bound to aliphatic C, whereas in the manure treatment SiO groups had higher affinity toward Cu than aliphatic C. Also, the sequence of binding of functional groups to Cu was modified by the fertilization treatments. Moreover, synchrotron-radiation-based FTIR spectromicroscopy showed that Cu, clay minerals and sesquioxides, and C functional groups were heterogeneously distributed at the micro-scale. Specifically, clay-OH as well as mineral elements had a distribution pattern similar to Cu, but certain (but not all) C forms showed a distribution pattern inconsistent with that of Cu. The combination of synchrotron radiation spectromicroscopy and 2DCOS is a useful tool in exploring the interactions among heavy metals, minerals and organic components in soils.
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Affiliation(s)
- Fusheng Sun
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yaqing Li
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiang Wang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zhilai Chi
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Guanghui Yu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
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Elliott JD, Poli E, Scivetti I, Ratcliff LE, Andrinopoulos L, Dziedzic J, Hine NDM, Mostofi AA, Skylaris C, Haynes PD, Teobaldi G. Chemically Selective Alternatives to Photoferroelectrics for Polarization-Enhanced Photocatalysis: The Untapped Potential of Hybrid Inorganic Nanotubes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1600153. [PMID: 28251044 PMCID: PMC5323885 DOI: 10.1002/advs.201600153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/24/2016] [Indexed: 05/31/2023]
Abstract
Linear-scaling density functional theory simulation of methylated imogolite nanotubes (NTs) elucidates the interplay between wall-polarization, bands separation, charge-transfer excitation, and tunable electrostatics inside and outside the NT-cavity. The results suggest that integration of polarization-enhanced selective photocatalysis and chemical separation into one overall dipole-free material should be possible. Strategies are proposed to increase the NT polarization for maximally enhanced electron-hole separation.
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Affiliation(s)
- Joshua D. Elliott
- Stephenson Institute for Renewable Energy and Department of ChemistryUniversity of LiverpoolLiverpoolL69 3BXUK
| | - Emiliano Poli
- Stephenson Institute for Renewable Energy and Department of ChemistryUniversity of LiverpoolLiverpoolL69 3BXUK
| | - Ivan Scivetti
- Stephenson Institute for Renewable Energy and Department of ChemistryUniversity of LiverpoolLiverpoolL69 3BXUK
| | - Laura E. Ratcliff
- The Thomas Young Centre for Theory and Simulation of MaterialsImperial College LondonLondonSW7 2AZUK
| | - Lampros Andrinopoulos
- The Thomas Young Centre for Theory and Simulation of MaterialsImperial College LondonLondonSW7 2AZUK
| | - Jacek Dziedzic
- School of ChemistryUniversity of SouthamptonSouthamptonSO17 1BJUK
- Faculty of Applied Physics and MathematicsGdansk University of TechnologyGdansk80 233Poland
| | | | - Arash A. Mostofi
- The Thomas Young Centre for Theory and Simulation of MaterialsImperial College LondonLondonSW7 2AZUK
| | | | - Peter D. Haynes
- The Thomas Young Centre for Theory and Simulation of MaterialsImperial College LondonLondonSW7 2AZUK
| | - Gilberto Teobaldi
- Stephenson Institute for Renewable Energy and Department of ChemistryUniversity of LiverpoolLiverpoolL69 3BXUK
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16
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Lam CH, Yang AC, Chi HY, Chan KY, Hsieh CC, Kang DY. Microwave-Assisted Synthesis of Highly Monodispersed Single-Walled Alunminosilicate Nanotubes. ChemistrySelect 2016. [DOI: 10.1002/slct.201601492] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Chon Hei Lam
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
| | - An-Chih Yang
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
| | - Heng-Yu Chi
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
| | - Kuan-Ying Chan
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
| | - Chih-Chen Hsieh
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
| | - Dun-Yen Kang
- Department of Chemical Engineering; National Taiwan University No. 1, Sec. 4; Roosevelt Road Taipei 10617 Taiwan
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17
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Poli E, Elliott JD, Ratcliff LE, Andrinopoulos L, Dziedzic J, Hine NDM, Mostofi AA, Skylaris CK, Haynes PD, Teobaldi G. The potential of imogolite nanotubes as (co-)photocatalysts: a linear-scaling density functional theory study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:074003. [PMID: 26808452 DOI: 10.1088/0953-8984/28/7/074003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We report a linear-scaling density functional theory (DFT) study of the structure, wall-polarization absolute band-alignment and optical absorption of several, recently synthesized, open-ended imogolite (Imo) nanotubes (NTs), namely single-walled (SW) aluminosilicate (AlSi), SW aluminogermanate (AlGe), SW methylated aluminosilicate (AlSi-Me), and double-walled (DW) AlGe NTs. Simulations with three different semi-local and dispersion-corrected DFT-functionals reveal that the NT wall-polarization can be increased by nearly a factor of four going from SW-AlSi-Me to DW-AlGe. Absolute vacuum alignment of the NT electronic bands and comparison with those of rutile and anatase TiO2 suggest that the NTs may exhibit marked propensity to both photo-reduction and hole-scavenging. Characterization of the NTs' band-separation and optical properties reveal the occurrence of (near-)UV inside-outside charge-transfer excitations, which may be effective for electron-hole separation and enhanced photocatalytic activity. Finally, the effects of the NTs' wall-polarization on the absolute alignment of electron and hole acceptor states of interacting water (H2O) molecules are quantified and discussed.
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Affiliation(s)
- E Poli
- Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, UK
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18
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Castro C, Arancibia-Miranda N, Acuña-Rougier C, Escudey M, Tasca F. Spectroscopic and Electrochemical Studies of Imogolite and Fe-Modified Imogolite Nanotubes. NANOMATERIALS (BASEL, SWITZERLAND) 2016; 6:E28. [PMID: 28344285 PMCID: PMC5302487 DOI: 10.3390/nano6020028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 11/28/2022]
Abstract
Carbon nanotubes and other forms of carbon nanoparticles, as well as metal nanoparticles have been widely used in film electrochemistry because they allow for the immobilization of larger amounts of catalyst (either biological or inorganic) on the top of the modified electrodes. Nevertheless, those nanoparticles present high costs of synthesis and of separation and purification that hamper their employment. On the other hand, imogolites (Im), with the general formula (OH)₃Al₂O₃SiOH, are naturally-occurring nanomaterials, which can be obtained from glassy volcanic ash soils and can also be synthesized at mild conditions. In this research paper, we characterize through spectroscopic techniques (i.e., fourier transform infrared spectroscopy (FTIR) spectroscopy, powder X-ray diffraction (XRD) and transmission electron microscopy (TEM)) synthetized Im and Fe-modified imogolite (Im(Fe)). Moreover, the Im and Im(Fe) were physically adsorbed on the top of a graphite electrode (GE) and were characterized electrochemically in the potential region ranging from -0.8 to 0.8 V vs. the saturated calomel electrode (SCE). When the film of the Im or of the Im(Fe) was present on the top of the electrode, the intensity of the charging/discharging current increased two-fold, but no redox activity in the absence of O₂ could be appreciated. To show that Im and Im(Fe) could be used as support for catalysts, iron phthalocyanine (FePc) was adsorbed on the top of the Im or Im(Fe) film, and the electrocatalytic activity towards the O₂ reduction was measured. In the presence of the Im, the measured electrocatalytic current for O₂ reduction increased 30%, and the overpotential drastically decreased by almost 100 mV, proving that the Im can act as a good support for the electrocatalysts.
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Affiliation(s)
- Carmen Castro
- Department of Chemistry of Materials, University of Santiago of Chile, 9170022 Santiago, Chile.
| | - Nicolas Arancibia-Miranda
- Department of Chemistry of Materials, University of Santiago of Chile, 9170022 Santiago, Chile.
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, 9170022 Santiago, Chile.
| | - Cristina Acuña-Rougier
- Department of Chemistry of Materials, University of Santiago of Chile, 9170022 Santiago, Chile.
| | - Mauricio Escudey
- Department of Chemistry of Materials, University of Santiago of Chile, 9170022 Santiago, Chile.
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, 9170022 Santiago, Chile.
| | - Federico Tasca
- Department of Chemistry of Materials, University of Santiago of Chile, 9170022 Santiago, Chile.
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19
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Kumar M, Luo H, Román-Leshkov Y, Rimer JD. SSZ-13 Crystallization by Particle Attachment and Deterministic Pathways to Crystal Size Control. J Am Chem Soc 2015; 137:13007-17. [PMID: 26376337 DOI: 10.1021/jacs.5b07477] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Many synthetic and natural crystalline materials are either known or postulated to grow via nonclassical pathways involving the initial self-assembly of precursors that serve as putative growth units for crystallization. Elucidating the pathway(s) by which precursors attach to crystal surfaces and structurally rearrange (postattachment) to incorporate into the underlying crystalline lattice is an active and expanding area of research comprising many unanswered fundamental questions. Here, we examine the crystallization of SSZ-13, which is an aluminosilicate zeolite that possesses exceptional physicochemical properties for applications in separations and catalysis (e.g., methanol upgrading to chemicals and the environmental remediation of NO(x)). We show that SSZ-13 grows by two concerted mechanisms: nonclassical growth involving the attachment of amorphous aluminosilicate particles to crystal surfaces and classical layer-by-layer growth via the incorporation of molecules to advancing steps on the crystal surface. A facile, commercially viable method of tailoring SSZ-13 crystal size and morphology is introduced wherein growth modifiers are used to mediate precursor aggregation and attachment to crystal surfaces. We demonstrate that small quantities of polymers can be used to tune crystal size over 3 orders of magnitude (0.1-20 μm), alter crystal shape, and introduce mesoporosity. Given the ubiquitous presence of amorphous precursors in a wide variety of microporous crystals, insight of the SSZ-13 growth mechanism may prove to be broadly applicable to other materials. Moreover, the ability to selectively tailor the physical properties of SSZ-13 crystals through molecular design offers new routes to optimize their performance in a wide range of commercial applications.
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Affiliation(s)
- Manjesh Kumar
- Chemical and Biomolecular Engineering, University of Houston , Houston, Texas 77204, United States
| | - Helen Luo
- Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Yuriy Román-Leshkov
- Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Jeffrey D Rimer
- Chemical and Biomolecular Engineering, University of Houston , Houston, Texas 77204, United States
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20
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Synthesis and immobilization of silver nanoparticles on aluminosilicate nanotubes and their antibacterial properties. APPLIED NANOSCIENCE 2015. [DOI: 10.1007/s13204-015-0467-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Kang DY, Brunelli NA, Yucelen GI, Venkatasubramanian A, Zang J, Leisen J, Hesketh PJ, Jones CW, Nair S. Direct synthesis of single-walled aminoaluminosilicate nanotubes with enhanced molecular adsorption selectivity. Nat Commun 2015; 5:3342. [PMID: 24531275 DOI: 10.1038/ncomms4342] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 01/29/2014] [Indexed: 11/09/2022] Open
Abstract
Internal functionalization of single-walled nanotubes is an attractive, yet difficult challenge in nanotube materials chemistry. Here we report single-walled metal oxide nanotubes with covalently bonded primary amine moieties on their inner wall, synthesized through a one-step approach. Conclusive molecular-level structural information on the amine-functionalized nanotubes is obtained through multiple solid-state techniques. The amine-functionalized nanotubes maintain a high carbon dioxide adsorption capacity while significantly suppressing the adsorption of methane and nitrogen, thereby leading to a large enhancement in adsorption selectivity over unfunctionalized nanotubes (up to four-fold for carbon dioxide/methane and ten-fold for carbon dioxide/nitrogen). The successful synthesis of single-walled nanotubes with functional, covalently-bound organic moieties may open up possibilities for new nanotube-based applications that are currently inaccessible to carbon nanotubes and other related materials.
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Affiliation(s)
- Dun-Yen Kang
- 1] School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, USA [2] Department of Chemical Engineering, National Taiwan University, No. 1, Sector 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Nicholas A Brunelli
- 1] School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, USA [2] Department of Chemical and Biomolecular Engineering, The Ohio State University, 125A Koffolt Laboratories, 140 West 19th Avenue, Columbus, Ohio 43210, USA
| | - G Ipek Yucelen
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332, USA
| | - Anandram Venkatasubramanian
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive NW, Atlanta, Georgia 30332, USA
| | - Ji Zang
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, USA
| | - Johannes Leisen
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332, USA
| | - Peter J Hesketh
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive NW, Atlanta, Georgia 30332, USA
| | - Christopher W Jones
- 1] School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, USA [2] School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332, USA
| | - Sankar Nair
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, USA
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22
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Ostwald’s rule of stages governs structural transitions and morphology of dipeptide supramolecular polymers. Nat Commun 2014; 5:5219. [DOI: 10.1038/ncomms6219] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/09/2014] [Indexed: 02/02/2023] Open
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López-Cebral R, Martín-Pastor M, Seijo B, Sanchez A. Progress in the characterization of bio-functionalized nanoparticles using NMR methods and their applications as MRI contrast agents. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2014; 79:1-13. [PMID: 24815362 DOI: 10.1016/j.pnmrs.2014.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 01/13/2014] [Accepted: 01/15/2014] [Indexed: 05/22/2023]
Abstract
Significant progress has been made over the last three decades in the field of NMR, a technique which has proven to have a variety of applications in many scientific disciplines, including nanotechnology. Herein we describe how NMR enables the characterization of nanosystems at different stages of their formation and modification (raw materials, bare or functionalized nanosystems), even making it possible to study in vivo nanoparticle interactions, thereby importantly contributing to nanoparticle design and subsequent optimization. Furthermore, the unique characteristics of nanosystems can open up new prospects for site-targeted, more specific contrast agents, contributing to the development of certain nuclear magnetic resonance applications such as MRI.
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Affiliation(s)
- Rita López-Cebral
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), Campus Sur, 15782 Santiago de Compostela, Spain
| | - Manuel Martín-Pastor
- Nuclear Magnetic Resonance Unit, RIADT, University of Santiago de Compostela (USC), Campus Vida, 15706 Santiago de Compostela, Spain
| | - Begoña Seijo
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), Campus Sur, 15782 Santiago de Compostela, Spain; Molecular ImageGroup, IDIS, Santiago de Compostela University Hospital Complex (CHUS), A Choupana, 15706 Santiago de Compostela, Spain
| | - Alejandro Sanchez
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), Campus Sur, 15782 Santiago de Compostela, Spain; Molecular ImageGroup, IDIS, Santiago de Compostela University Hospital Complex (CHUS), A Choupana, 15706 Santiago de Compostela, Spain.
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24
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Kim WG, Nair S. Membranes from nanoporous 1D and 2D materials: A review of opportunities, developments, and challenges. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2013.09.047] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Guimarães L, Pinto YN, Lourenço MP, Duarte HA. Imogolite-like nanotubes: structure, stability, electronic and mechanical properties of the phosphorous and arsenic derivatives. Phys Chem Chem Phys 2013; 15:4303-9. [PMID: 23407893 DOI: 10.1039/c3cp44250k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Imogolite is a single-walled aluminosilicate nanotube (NT) found in nature that can be easily synthesized, as well as its analogue aluminogermanate NT. Based on geometrical assumptions and pKa values, species such as H3PO4, H3PO3, H3AsO3, H3AsO4 could also be candidates to form imogolite-like structures. In the present work, we provide insights about the stability, electronic, structural and mechanical properties of possible imogolite like NTs by means of self-consistent charge density-functional tight-binding method (SCC-DFTB). Similarly to aluminogermanate, where the tetrahedral silicate groups are replaced by germanate, in this work tetrahedral silicate groups are substituted by phosphate, phosphite, arsenate and arsenite units in the imogolite structure. Detailed analysis is focused on structural properties, strain energy, band gap and Mulliken charges distribution. The calculated strain energy curves for all studied zigzag imogolite-like NTs present well-defined minima, which change as a consequence of composition variation. Moreover, the strain energy curves of armchair imogolite-like NTs also present minima, although in all cases less stable than zigzags by at least 2.2 meV per atom. The insulating NT behaviour changes after internal modification from silicate to phosphate, phosphite, arsenate and arsenite, as well as the charge distribution inside and outside the nanotubes.
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Affiliation(s)
- Luciana Guimarães
- Department of Natural Science, Universidade Federal de São João Del Rei, São João Del Rei, MG, Brazil.
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26
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Bogatko S, Cauët E, Geerlings P. Improved DFT-based interpretation of ESI-MS of aqueous metal cations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:926-931. [PMID: 23595261 DOI: 10.1007/s13361-013-0617-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/13/2013] [Accepted: 03/13/2013] [Indexed: 06/02/2023]
Abstract
We present results showing that our recently developed density functional theory (DFT)-based speciation model of the aqueous Al(3+) system has the potential to improve the interpretations of ESI-MS studies of aqueous metal cation hydrolytic speciation. The main advantages of our method are that (1) it allows for the calculation of the relative abundance of a given species which may be directly assigned to the signal intensity in a mass spectrum; (2) in cases where species with identical m⁄z ratios may coexist, the assignment can be unambiguously assigned based on their theoretical relative abundances. As a demonstration of its application, we study four pairs of monomer and dimer aqueous Al(3+) species, each with identical m/z ratio. For some of these pairs our method predicts that the dominant species changes from the monomer to the dimer species under varying pH conditions.
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Affiliation(s)
- Stuart Bogatko
- Eenheid Algemene Chemie, Vrije Universiteit Brussel (VUB), Faculteit Wetenschappen, 1050, Brussels, Belgium.
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27
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Yucelen GI, Kang DY, Schmidt-Krey I, Beckham HW, Nair S. A generalized kinetic model for the formation and growth of single-walled metal oxide nanotubes. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2012.12.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Arancibia-Miranda N, Escudey M, Molina M, García-González MT. Kinetic and Surface Study of Single-Walled Aluminosilicate Nanotubes and Their Precursors. NANOMATERIALS 2013; 3:126-140. [PMID: 28348326 PMCID: PMC5304925 DOI: 10.3390/nano3010126] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/10/2013] [Accepted: 02/11/2013] [Indexed: 11/21/2022]
Abstract
The structural and surface changes undergone by the different precursors that are produced during the synthesis of imogolite are reported. The surface changes that occur during the synthesis of imogolite were determined by electrophoretic migration (EM) measurements, which enabled the identification of the time at which the critical precursor of the nanoparticles was generated. A critical parameter for understanding the evolution of these precursors is the isoelectric point (IEP), of which variation revealed that the precursors modify the number of active ≡Al-OH and ≡Si-OH sites during the formation of imogolite. We also found that the IEP is displaced to a higher pH level as a consequence of the surface differentiation that occurs during the synthesis. At the same time, we established that the pH of the reaction (pHrx) decreases with the evolution and condensation of the precursors during aging. Integration of all of the obtained results related to the structural and surface properties allows an overall understanding of the different processes that occur and the products that are formed during the synthesis of imogolite.
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Affiliation(s)
- Nicolás Arancibia-Miranda
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago 9170124, Chile.
- Faculty of Chemistry and Biology, University of Santiago of Chile, Av. B. O'Higgins, Santiago 3363, Chile.
| | - Mauricio Escudey
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago 9170124, Chile.
- Faculty of Chemistry and Biology, University of Santiago of Chile, Av. B. O'Higgins, Santiago 3363, Chile.
| | - Mauricio Molina
- Departament of Industry, Federico Santa María Technical University, Av. Santa María 6400, Santiago 766-0251, Chile.
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A Novel Fluoride Route for the Synthesis of Aluminosilicate Nanotubes. NANOMATERIALS 2013; 3:117-125. [PMID: 28348325 PMCID: PMC5304928 DOI: 10.3390/nano3010117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/28/2013] [Accepted: 01/29/2013] [Indexed: 11/17/2022]
Abstract
In this work we present a novel method for synthesis of aluminosilicate nanotubes: the fluoride route. F-containing imogolite (F-IMO) exhibits an improved crystallization rate and improved yield. The structure of F-IMO was investigated and compared with F-free imogolite (IMO) by means of X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FTIR) confirming imogolite structure. Solid state nuclear magnetic resonance (NMR) analyses show an increased crystallization rate for F-IMO and confirm the incorporation of fluorine ion in the structure.
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30
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Liu W, Chaurand P, Di Giorgio C, De Méo M, Thill A, Auffan M, Masion A, Borschneck D, Chaspoul F, Gallice P, Botta A, Bottero JY, Rose J. Influence of the length of imogolite-like nanotubes on their cytotoxicity and genotoxicity toward human dermal cells. Chem Res Toxicol 2012; 25:2513-22. [PMID: 22989002 DOI: 10.1021/tx3003214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Physical-chemical parameters such as purity, structure, chemistry, length, and aspect ratio of nanoparticles (NPs) are linked to their toxicity. Here, synthetic imogolite-like nanotubes with a set chemical composition but various sizes and shapes were used as models to investigate the influence of these physical parameters on the cyto- and genotoxicity and cellular uptake of NPs. The NPs were characterized using X-ray diffraction (XRD), small angle X-ray scattering (SAXS), and atomic force microscopy (AFM). Imogolite precursors (PR, ca. 5 nm curved platelets), as well as short tubes (ST, ca. 6 nm) and long tubes (LT, ca. 50 nm), remained stable in the cell culture medium. Internalization into human fibroblasts was observed only for the small particles PR and ST. None of the tested particles induced a significant cytotoxicity up to a concentration of 10(-1) mg·mL(-1). However, small sized NPs (PR and ST) were found to be genotoxic at very low concentration 10(-6) mg·mL(-1), while LT particles exhibited a weak genotoxicity. Our results indicate that small size NPs (PR, ST) were able to induce primary lesions of DNA at very low concentrations and that this DNA damage was exclusively induced by oxidative stress. The higher aspect ratio LT particles exhibited a weaker genotoxicity, where oxidative stress is a minor factor, and the likely involvement of other mechanisms. Moreover, a relationship among cell uptake, particle aspect ratio, and DNA damage of NPs was observed.
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Affiliation(s)
- Wei Liu
- CEREGE, UMR 7330, CNRS-Aix Marseille University, BP 80, 13545 Aix en Provence, France
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31
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Thill A, Maillet P, Guiose B, Spalla O, Belloni L, Chaurand P, Auffan M, Olivi L, Rose J. Physico-chemical control over the single- or double-wall structure of aluminogermanate imogolite-like nanotubes. J Am Chem Soc 2012; 134:3780-6. [PMID: 22296596 DOI: 10.1021/ja209756j] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is known that silicon can be successfully replaced by germanium atoms in the synthesis of imogolite nanotubes, leading to shorter and larger AlGe nanotubes. Beside the change in morphology, two characteristics of the AlGe nanotube synthesis were recently discovered. AlGe imogolite nanotubes can be synthesized at much higher concentrations than AlSi imogolite. AlGe imogolite exists in the form of both single-walled (SW) and double-walled (DW) nanotubes, whereas DW AlSi imogolites have never been observed. In this article, we give details on the physicochemical control over the SW or DW AlGe imogolite structure. For some conditions, an almost 100% yield of SW or DW nanotubes is demonstrated. We propose a model for the formation of SW or DW AlGe imogolite, which also explains why DW AlSi imogolites or higher wall numbers for AlGe imogolite are not likely to be formed.
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Affiliation(s)
- Antoine Thill
- CEA Saclay, IRAMIS, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire, 91191 Gif-sur-Yvette cedex, France.
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32
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Yucelen GI, Kang DY, Guerrero-Ferreira RC, Wright ER, Beckham HW, Nair S. Shaping single-walled metal oxide nanotubes from precursors of controlled curvature. NANO LETTERS 2012; 12:827-832. [PMID: 22268908 DOI: 10.1021/nl203880z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We demonstrate new molecular-level concepts for constructing nanoscopic metal oxide objects. First, the diameters of metal oxide nanotubes are shaped with angstrom-level precision by controlling the shape of nanometer-scale precursors. Second, we measure (at the molecular level) the subtle relationships between precursor shape and structure and final nanotube curvature. Anionic ligands are used to exert fine control over precursor shapes, allowing assembly into nanotubes whose diameters relate directly to the curvatures of the 'shaped' precursors.
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Affiliation(s)
- G Ipek Yucelen
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Kang DY, Tong HM, Zang J, Choudhury RP, Sholl DS, Beckham HW, Jones CW, Nair S. Single-walled aluminosilicate nanotube/poly(vinyl alcohol) nanocomposite membranes. ACS APPLIED MATERIALS & INTERFACES 2012; 4:965-976. [PMID: 22260317 DOI: 10.1021/am201614w] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The fabrication, detailed characterization, and molecular transport properties of nanocomposite membranes containing high fractions (up to 40 vol %) of individually-dispersed aluminosilicate single-walled nanotubes (SWNTs) in poly(vinyl alcohol) (PVA), are reported. The microstructure, SWNT dispersion, SWNT dimensions, and intertubular distances within the composite membranes are characterized by scanning and transmission electron microscopy (SEM and TEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), XRD rocking curve analysis, small-angle X-ray scattering (SAXS), and solid-state NMR. PVA/SWNT nanocomposite membranes prepared from SWNT gels allow uniform dispersion of individual SWNTs in the PVA matrix with a random distribution of orientations. SAXS analysis reveals the length (∼500 nm) and outer diameter (~2.2 nm) of the dispersed SWNTs. Electron microscopy indicates good adhesion between the SWNTs and the PVA matrix without the occurrence of defects such as voids and pinholes. The transport properties of the PVA/SWNT membranes are investigated experimentally by ethanol/water mixture pervaporation measurements, computationally by grand canonical Monte Carlo and molecular dynamics, and by a macroscopic transport model for anisotropic permeation through nanotube-polymer composite membranes. The nanocomposite membranes substantially enhance the water throughput with increasing SWNT volume fraction, which leads to a moderate reduction of the water/ethanol selectivity. The model is parameterized purely from molecular simulation data with no fitted parameters, and shows reasonably good agreement with the experimental water permeability data.
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Affiliation(s)
- Dun-Yen Kang
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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