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Pignié MC, Patra S, Huart L, Milosavljević AR, Renault JP, Leroy J, Nicolas C, Sublemontier O, Le Caër S, Thill A. Experimental determination of the curvature-induced intra-wall polarization of inorganic nanotubes. NANOSCALE 2021; 13:19650-19662. [PMID: 34816859 DOI: 10.1039/d1nr06462b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Inspired by a natural nano-mineral known as imogolite, aluminosilicate inorganic nanotubes are appealing systems for photocatalysis. Here, we studied two types of synthetic imogolites: one is completely hydrophilic (IMO-OH), while the other has a hydrophilic exterior and a hydrophobic interior (IMO-CH3), enabling the encapsulation of organic molecules. We combined UV-Vis diffuse reflectance spectroscopy of imogolite powders and X-ray photoelectron spectroscopy of deposited imogolite films and isolated nanotubes agglomerates to obtain not only the band structure, but also the quantitative intra-wall polarization of both synthetic imogolites for the first time. The potential difference across the imogolite wall was determined to be 0.7 V for IMO-OH and around 0.2 V for IMO-CH3. The high curvature of the nanotubes, together with the thinness of their wall, favors efficient spontaneous charge separation and electron exchange reactions on both the internal and external nanotube surfaces. In addition, the positions of their valence and conduction band edges make them interesting candidates for co-catalysts or doped catalysts for water splitting, among other possible photocatalytic reactions relevant to energy and the environment.
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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.
| | - Sabyasachi Patra
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Lucie Huart
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | | | - Jean Philippe Renault
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Jocelyne Leroy
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Christophe Nicolas
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
| | - Olivier Sublemontier
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Sophie Le Caër
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Antoine Thill
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
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2
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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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3
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Serra M, Arenal R, Tenne R. An overview of the recent advances in inorganic nanotubes. NANOSCALE 2019; 11:8073-8090. [PMID: 30994692 DOI: 10.1039/c9nr01880h] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Advanced nanomaterials play a prominent role in nanoscience and nanotechnology developments, opening new frontiers in these areas. Among these nanomaterials, due to their unique characteristics and enhanced chemical and physical properties, inorganic nanotubes have been considered one of the most interesting nanostructures. In recent years, important progress has been achieved in the production and study of these nanomaterials, including boron nitride, transition metal dichalcogenide nanotubular structures, misfit-based nanotubes and other hybrid/doped nanotubular objects. This review is devoted to the in-depth analysis of recent studies on the synthesis, atomic structures, properties and applications of inorganic nanotubes and related nanostructures. Particular attention is paid to the growth mechanism of these nanomaterials. This is a crucial point for the challenges ahead related to the mass production of high-quality defect-free nanotubes for a variety of applications.
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Affiliation(s)
- Marco Serra
- Department of Materials and Interfaces, Weizmann Institute, Herzl Street 234, 76100, Rehovot, Israel.
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4
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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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5
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Picot P, Liao Y, Barruet E, Gobeaux F, Coradin T, Thill A. Exploring Hybrid Imogolite Nanotube Formation via Si/Al Stoichiometry Control. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:13225-13234. [PMID: 30296100 DOI: 10.1021/acs.langmuir.8b01075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hybrid imogolite aluminosilicate nanotubes with methylated internal surface can be obtained by introduction of the corresponding organosilane during their synthesis. However, similarly to pristine imogolite, a number of side products, including proto-imogolite (open-imoLS), allophanes, and aluminum hydroxides, are formed, which ultimately impact on the properties of the dispersions. In order to minimize the proportion of these side products, we have here systematically explored the impact of the initial Si/Al ratio on the content of hybrid imogolite dispersions before and after dialysis. By combining cryo-transmission electron microscopy, inductively coupled plasma mass spectrometry, infrared spectroscopy, and small-angle X-ray scattering, we evidenced that the Si/Al ratio has a large impact on the formation of aluminum hydroxides that can be minimized with a slight excess of Si precursor. However, a large excess of Si is detrimental to the reaction yield leading to an important proportion of proto-imogolite. We propose that the optimal Si/Al ratio of ca. 0.6 can both minimize the proportion of aluminum hydroxides and proto-imogolite. These results suggest that the dynamic and therefore reactive character of imogolite dispersions may have been so far underlooked.
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Affiliation(s)
- Pierre Picot
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA-Saclay , 91191 Gif-sur-Yvette , France
| | - Yuanyuan Liao
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA-Saclay , 91191 Gif-sur-Yvette , France
| | - Elodie Barruet
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA-Saclay , 91191 Gif-sur-Yvette , France
| | - Frédéric Gobeaux
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA-Saclay , 91191 Gif-sur-Yvette , France
| | - Thibaud Coradin
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Collège de France, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP) , 4 place Jussieu , 75005 Paris , France
| | - Antoine Thill
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA-Saclay , 91191 Gif-sur-Yvette , France
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6
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Imogolite Nanotubes: A Flexible Nanoplatform with Multipurpose Applications. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8101921] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Among a wide variety of inorganic nanotubes, imogolite nanotubes (INTs) represent a model of nanoplatforms with an untapped potential for advanced technological applications. Easily synthesized by sol-gel methods, these nanotubes are directly obtained with a monodisperse pore size. Coupled with the possibility to adjust their surface properties by using straightforward functionalization processes, INTs form a unique class of diameter-controlled nanotubes with functional interfaces. The purpose of this review is to provide the reader with an overview of the synthesis and functionalization of INTs. The properties of INTs will be stated afterwards into perspective with the recent development on their applications, in particular for polymer/INTs nanocomposites, molecular confinement or catalysis.
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7
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Photo-activated degradation of tartrazine by H 2 O 2 as catalyzed by both bare and Fe-doped methyl-imogolite nanotubes. Catal Today 2018. [DOI: 10.1016/j.cattod.2017.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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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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9
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Levard C, Thill A, Avellan A, Mauroy C, Vidal V, Campos APC, Masion A, Rose J. Alignment of Ge-imogolite nanotubes in isomalt with tunable inter-tube distances. RSC Adv 2017. [DOI: 10.1039/c7ra01380a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study shows the almost perfect alignment of inorganic nanotubes (Ge-imogolite) within polyol filaments.
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Affiliation(s)
| | | | | | | | | | - Andrea P. C. Campos
- Aix-Marseille Université
- CP2M
- Faculté des Sciences
- Campus de St Jérôme
- F-13397 Marseille
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10
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Reactivity of bare and Fe-doped alumino-silicate nanotubes (imogolite) with H2O2 and the azo-dye Acid Orange 7. Catal Today 2016. [DOI: 10.1016/j.cattod.2015.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Picot P, Taché O, Malloggi F, Coradin T, Thill A. Behaviour of hybrid inside/out Janus nanotubes at an oil/water interface. A route to self-assembled nanofluidics? Faraday Discuss 2016; 191:391-406. [PMID: 27440374 DOI: 10.1039/c6fd00034g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Imogolites are natural aluminosilicate nanotubes that have a diameter of a few nanometers and can be several microns long. These nanotubes have different chemical groups on their internal (Si-OH) and external (Al-OH-Al) surfaces, that can be easily functionalised independently on both surfaces. Here we show that taking advantage of the particular shape and chemistry of imogolite, it is possible to prepare inside/out Janus nanotubes. Two kinds of symmetric Janus nanotubes are prepared: one with an external hydrophilic surface and an internal hydrophobic cavity (imo-CH3) and one with an external hydrophobic surface and a hydrophilic internal cavity (OPA-imo). The behaviour of such inside/out Janus nanotubes at oil/water interfaces is studied. The OPA-imo adsorbs strongly at the oil/water interface and is very efficient in stabilising water-in-oil emulsions through an arrested coalescence mechanism. Imo-CH3 also adsorbs at the oil/water interface. It stabilises oil-in-water emulsions by inducing slow oil-triggered modifications of the viscosity of the continuous phase. The possible transport of small molecules inside the imo-CH3 nanotubes is evidenced, opening up routes towards self-assembled nanofluidics.
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Affiliation(s)
- P Picot
- LIONS, NIMBE, CEA, CNRS, Université Paris-Saclay, 91191 Gif sur Yvette, France.
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12
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Avellan A, Auffan M, Masion A, Levard C, Bertrand M, Rose J, Santaella C, Achouak W. Remote Biodegradation of Ge-Imogolite Nanotubes Controlled by the Iron Homeostasis of Pseudomonas brassicacearum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7791-7798. [PMID: 27347687 DOI: 10.1021/acs.est.6b01455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The toxicity of high-aspect-ratio nanomaterials (HARNs) is often associated with oxidative stress. The essential nutrient Fe may also be responsible of oxidative stress through the production of reactive oxygen species. In the present study, it has been examined to what extent adding Fenton reaction promoting Fe impacted the toxicity of an alumino-germanate model HARN. Structural addition of only 0.95% wt Fe to Ge-imogolite not only alleviated the toxicity observed in the case of Fe-free nanotubes but also stimulated bacterial growth. This was attributed to the metabolization of siderophore-mobilized Fe from the nanotube structure. This was evidenced by the regulation of the homeostasis-monitoring intracellular Fe levels. This was accompanied by a biodegradation of the nanotubes approaching 40%, whereas the Fe-free nanomaterial remained nearly untouched.
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Affiliation(s)
- Astrid Avellan
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , 13545 Aix en Provence, France
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
- Laboratory of Microbial Ecology of the Rhizosphere and Extreme Environments (LEMIRE), Aix-Marseille Université, CEA, CNRS, UMR 7265 Biosciences and Biotechnology Institute of Aix-Marseille (BIAM), ECCOREV FR 3098, CEA/Cadarache , 13108 St-Paul-lez-Durance, France
| | - Melanie Auffan
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , 13545 Aix en Provence, France
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
| | - Armand Masion
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , 13545 Aix en Provence, France
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
| | - Clément Levard
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , 13545 Aix en Provence, France
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
| | - Marie Bertrand
- Laboratory of Microbial Ecology of the Rhizosphere and Extreme Environments (LEMIRE), Aix-Marseille Université, CEA, CNRS, UMR 7265 Biosciences and Biotechnology Institute of Aix-Marseille (BIAM), ECCOREV FR 3098, CEA/Cadarache , 13108 St-Paul-lez-Durance, France
| | - Jérôme Rose
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , 13545 Aix en Provence, France
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
| | - Catherine Santaella
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
- Laboratory of Microbial Ecology of the Rhizosphere and Extreme Environments (LEMIRE), Aix-Marseille Université, CEA, CNRS, UMR 7265 Biosciences and Biotechnology Institute of Aix-Marseille (BIAM), ECCOREV FR 3098, CEA/Cadarache , 13108 St-Paul-lez-Durance, France
| | - Wafa Achouak
- iCEINT, International Consortium for the Environmental Implications of NanoTechology, CNRS, Duke University , Europôle de l'Arbois, 13545 Aix-en-Provence, France
- Laboratory of Microbial Ecology of the Rhizosphere and Extreme Environments (LEMIRE), Aix-Marseille Université, CEA, CNRS, UMR 7265 Biosciences and Biotechnology Institute of Aix-Marseille (BIAM), ECCOREV FR 3098, CEA/Cadarache , 13108 St-Paul-lez-Durance, France
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13
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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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14
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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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15
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Avellan A, Levard C, Chaneac C, Borschneck D, Onofri FRA, Rose J, Masion A. Accelerated microwave assisted synthesis of alumino-germanate imogolite nanotubes. RSC Adv 2016. [DOI: 10.1039/c6ra19275k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microwave assisted synthesis of Ge-imogolite nanotubes reduced the time required for their growth and shifted their length repartition towards larger values.
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Affiliation(s)
- A. Avellan
- Aix-Marseille Université
- CNRS
- IRD
- Collège de France
- CEREGE
| | - C. Levard
- Aix-Marseille Université
- CNRS
- IRD
- Collège de France
- CEREGE
| | - C. Chaneac
- Chimie de la Matière Condensée de Paris
- UMR7574 (UPMC/CNRS)
- Collège de France
- 75231 Paris
- France
| | - D. Borschneck
- Aix-Marseille Université
- CNRS
- IRD
- Collège de France
- CEREGE
| | | | - J. Rose
- Aix-Marseille Université
- CNRS
- IRD
- Collège de France
- CEREGE
| | - A. Masion
- Aix-Marseille Université
- CNRS
- IRD
- Collège de France
- CEREGE
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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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