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Christoforidis KC, Fernández-García M. Photoactivity and charge trapping sites in copper and vanadium doped anatase TiO2 nano-materials. Catal Sci Technol 2016. [DOI: 10.1039/c5cy00929d] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Isolated dopant species and metal cluster formation regulate the photoactivity and charge carrier formation via accepting e− and eliminating Ti3+ states.
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6
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Gourier D, Delpoux O, Bonduelle A, Binet L, Ciofini I, Vezin H. EPR, ENDOR, and HYSCORE Study of the Structure and the Stability of Vanadyl−Porphyrin Complexes Encapsulated in Silica: Potential Paramagnetic Biomarkers for the Origin of Life. J Phys Chem B 2010; 114:3714-25. [DOI: 10.1021/jp911728e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Didier Gourier
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
| | - Olivier Delpoux
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
| | - Audrey Bonduelle
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
| | - Laurent Binet
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
| | - Ilaria Ciofini
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
| | - Hervé Vezin
- Laboratoire de Chimie de la Matière Condensée de Paris, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech) and Université Pierre et Marie Curie, UMR-CNRS 7574, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, Laboratoire d’Electrochimie, Chimie des Interfaces et Modélisation pour l’Energie, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), UMR-CNRS 7575, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France, and Laboratoire de Spectrochimie Infrarouge et
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7
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Izumi Y, Konishi K, Obaid DM, Miyajima T, Yoshitake H. X-ray Absorption Fine Structure Combined with X-ray Fluorescence Spectroscopy. Monitoring of Vanadium Sites in Mesoporous Titania, Excited under Visible Light by Selective Detection of Vanadium Kβ5,2 Fluorescence. Anal Chem 2007; 79:6933-40. [PMID: 17711350 DOI: 10.1021/ac070427p] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photocatalytic role of vanadium doped in mesoporous TiO2 has not been clarified. Valence state-sensitive V Kbeta5,2-selecting (5462.9 eV) X-ray absorption fine structure (XAFS) was used to monitor the V sites in mesoporous TiO2 for ethanol dehydration under equilibrium in situ conditions and visible light-illumination. First, the feasibility of discriminating V(IV) sites from a 1:1 physical mixture of standard V(IV) and V(V) inorganic compounds was demonstrated, by tuning the secondary fluorescence spectrometer to 5459.0 eV. The chemical shift of V Kbeta5,2 emission between V(IV) and V(V) sites was 1.0 eV. The selection of valence states V(IV) and V(V) was 100% and 80%, respectively. The redox states for ethanol dehydration over mesoporous TiO2 excited in visible light were suggested to be V(III) and V(IV). The chemical shift between valence states V(III) and V(IV) was greater (3.2 eV). On the basis of V Kbeta5,2 emission and V Kbeta5,2-selecting XAFS spectra tuned to the V Kbeta5,2 peak, we determined that the fresh mesoporous V-TiO2 catalyst has a valence state of V(IV). The vanadium sites were partially reduced by the dissociative adsorption of ethanol under visible light, but they still stay within the emission-energy ranges for standard V(IV) compounds. These partially reduced vanadium sites were reoxidized in oxygen under visible light. Finally, direct XAFS observation of photoreduced V(III) sites was attempted by tuning the fluorescence spectrometer to 5456.3 eV for partially reduced mesoporous V-TiO2. Valence state V(III) was selected for 60% of the spectrum in the mixture of V(III) (minor) and V(IV) (dominant) valence states.
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Affiliation(s)
- Yasuo Izumi
- Department of Chemistry, Graduate School of Science, Chiba University, Yayoi 1-33, Chiba 263-8522, Japan.
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10
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Izumi Y, Kiyotaki F, Yagi N, Vlaicu AM, Nisawa A, Fukushima S, Yoshitake H, Iwasawa Y. X-ray Absorption Fine Structure Combined with X-ray Fluorescence Spectrometry. Part 15. Monitoring of Vanadium Site Transformations on Titania and in Mesoporous Titania by Selective Detection of the Vanadium Kα1Fluorescence. J Phys Chem B 2005; 109:14884-91. [PMID: 16852885 DOI: 10.1021/jp052038+] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
X-ray absorption fine structure combined with X-ray fluorescence spectrometry was applied to various V+TiO2 hybrid samples. Emitted V K alpha1 fluorescence from the sample was selectively counted by using a high-energy-resolution (0.4 eV) spectrometer equipped with a Ge(331) crystal. Two advantages of this method, extremely high signal/background ratio and the compatibility of measurements in the atmosphere of reaction gas (in situ study in relation to heterogeneous catalysis), were effective at the V K-edge. Structure transformation of the V sites was spectroscopically followed for the V/TiO2 catalyst. The monooxo tetrahedral vanadate site was demonstrated to exist at 473 K. It transformed into dispersed species of 5-fold coordination in ambient air and further into polymeric VO(x) species in 0.85 kPa of water at 290 K. In the presence of 3.2 kPa of 2-propanol, dissociative adsorption of 2-propanol on the dispersed V species was strongly suggested at 290-473 K. In situ structure changes of V sites on TiO2 were reported by means of XAFS for the first time. The V(V) sites for the V/TiO2 catalysts were essentially identical with those for V supported on mesoporous (high-surface-area) TiO2 and V-TiO2 sample prepared by the sol-gel method. However, predominant V(IV) sites were found for mesoporous V-TiO2. The V(IV) sites substituted on the Ti sites of TiO2. When the molar ratio of V/Ti increased from 1/100 to 1/5.0, major octahedral V sites in the TiO2 matrix looked to transform into tetrahedral ones.
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Affiliation(s)
- Yasuo Izumi
- Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta 4259-G1-16, Midori-ku, Yokohama 226-8502, Japan.
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12
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Nielsen UG, Topsøe NY, Brorson M, Skibsted J, Jakobsen HJ. The complete 51V MAS NMR spectrum of surface vanadia nanoparticles on anatase (TiO2): vanadia surface structure of a DeNOx catalyst. J Am Chem Soc 2004; 126:4926-33. [PMID: 15080698 DOI: 10.1021/ja030091a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first observations of the complete manifold of spinning sidebands (ssbs) including both the central and satellite transitions in (51)V MAS NMR spectra of surface vanadia nanoparticles on titania in DeNO(x) catalysts are presented. (51)V quadrupole coupling and chemical shift anisotropy parameters for the dominating vanadia structure are determined from (51)V MAS NMR spectra recorded at 9.4 and 14.1 T. Based on correlations previously established between (51)V NMR parameters and crystal structure data for inorganic vanadates, the NMR data are consistent with vanadium in a distorted octahedral oxygen coordination environment for the so-called strongly bonded vanadia species on the surface. The investigation includes two vanadia-titania model catalysts and six industrial-type DeNO(x) catalysts.
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Affiliation(s)
- Ulla Gro Nielsen
- Instrument Centre for Solid-State NMR Spectroscopy, Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark
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14
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Gopinath CS, Raja T. Comment on “Sintering and Phase Transformation of V-Loaded Anatase Materials Containing Bulk and Surface V Species”. J Phys Chem B 2001. [DOI: 10.1021/jp012289s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Balikdjian JP, Davidson A, Launay S, Eckert H, Che M. Reply to the Comment on “Sintering and Phase Transformation of V-Loaded Anatase Materials Containing Bulk and Surface V Species”. J Phys Chem B 2001. [DOI: 10.1021/jp013259s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. P. Balikdjian
- Laboratoire de Réactivite de Surface, UMR 7609 CNRS, Université Pierre et Marie Curie, Paris, 75252 Cedex 05, France
| | - A. Davidson
- Laboratoire de Réactivite de Surface, UMR 7609 CNRS, Université Pierre et Marie Curie, Paris, 75252 Cedex 05, France
| | - S. Launay
- Laboratoire de Réactivite de Surface, UMR 7609 CNRS, Université Pierre et Marie Curie, Paris, 75252 Cedex 05, France
| | - H. Eckert
- Laboratoire de Réactivite de Surface, UMR 7609 CNRS, Université Pierre et Marie Curie, Paris, 75252 Cedex 05, France
| | - M. Che
- Laboratoire de Réactivite de Surface, UMR 7609 CNRS, Université Pierre et Marie Curie, Paris, 75252 Cedex 05, France
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