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Ouf FX, Parent P, Laffon C, Marhaba I, Ferry D, Marcillaud B, Antonsson E, Benkoula S, Liu XJ, Nicolas C, Robert E, Patanen M, Barreda FA, Sublemontier O, Coppalle A, Yon J, Miserque F, Mostefaoui T, Regier TZ, Mitchell JBA, Miron C. First in-flight synchrotron X-ray absorption and photoemission study of carbon soot nanoparticles. Sci Rep 2016; 6:36495. [PMID: 27883014 PMCID: PMC5121651 DOI: 10.1038/srep36495] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/17/2016] [Indexed: 11/25/2022] Open
Abstract
Many studies have been conducted on the environmental impacts of combustion generated aerosols. Due to their complex composition and morphology, their chemical reactivity is not well understood and new developments of analysis methods are needed. We report the first demonstration of in-flight X-ray based characterizations of freshly emitted soot particles, which is of paramount importance for understanding the role of one of the main anthropogenic particulate contributors to global climate change. Soot particles, produced by a burner for several air-to-fuel ratios, were injected through an aerodynamic lens, focusing them to a region where they interacted with synchrotron radiation. X-ray photoelectron spectroscopy and carbon K-edge near-edge X-ray absorption spectroscopy were performed and compared to those obtained for supported samples. A good agreement is found between these samples, although slight oxidation is observed for supported samples. Our experiments demonstrate that NEXAFS characterization of supported samples provides relevant information on soot composition, with limited effects of contamination or ageing under ambient storage conditions. The highly surface sensitive XPS experiments of airborne soot indicate that the oxidation is different at the surface as compared to the bulk probed by NEXAFS. We also report changes in soot's work function obtained at different combustion conditions.
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Affiliation(s)
- F.-X. Ouf
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, LPMA, Gif-Sur-Yvette, 91192, France
| | - P. Parent
- Aix Marseille Univ, CNRS, CINAM, Marseille, France
| | - C. Laffon
- Aix Marseille Univ, CNRS, CINAM, Marseille, France
| | - I. Marhaba
- Aix Marseille Univ, CNRS, CINAM, Marseille, France
| | - D. Ferry
- Aix Marseille Univ, CNRS, CINAM, Marseille, France
| | - B. Marcillaud
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, LPMA, Gif-Sur-Yvette, 91192, France
| | - E. Antonsson
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
- Physical Chemistry, Freie Universität Berlin Takustr. 3, D-14195 Berlin, Germany
| | - S. Benkoula
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - X.-J. Liu
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191,China
| | - C. Nicolas
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - E. Robert
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - M. Patanen
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
- Nano and Molecular Systems Research Unit, Molecular Materials Research Community, Faculty of Science, P.O. Box 3000, 90014 University of Oulu, Finland
| | - F.-A. Barreda
- NIMBE/CEA/CNRS/Université Paris-Saclay/Laboratoire Edifices Nanométriques, CEA Saclay, Gif-sur-Yvette Cedex, 91191, France
| | - O. Sublemontier
- NIMBE/CEA/CNRS/Université Paris-Saclay/Laboratoire Edifices Nanométriques, CEA Saclay, Gif-sur-Yvette Cedex, 91191, France
| | - A. Coppalle
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, CORIA, 76000 Rouen, France
| | - J. Yon
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, CORIA, 76000 Rouen, France
| | - F. Miserque
- CEA/DEN/DPC/SCCME/Laboratoire d’Etude de la Corrosion Aqueuse, CEA Saclay, Gif-sur-Yvette Cedex, 91191, France
| | - T. Mostefaoui
- Laboratoire de Physico-Chimie des Matériaux et Catalyse, Faculté des Sciences Exactes, Université de Bejaia, 06000 Bejaia, Algérie
| | - T. Z. Regier
- Canadian Light Source, Saskatoon, SK S7N 2V3, Canada
| | - J.-B. A. Mitchell
- Institut de Physique de Rennes, UMR 6251, Université Rennes 1, Rennes Cedex, 35042, France
| | - C. Miron
- Synchrotron SOLEIL, Saint Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
- Extreme Light Infrastructure - Nuclear Physiscs (ELI-NP), “Horia Hulubei” National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov, Romania
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Takashiro JI, Kudo Y, Hao SJ, Takai K, Futaba DN, Enoki T, Kiguchi M. Preferential oxidation-induced etching of zigzag edges in nanographene. Phys Chem Chem Phys 2014; 16:21363-71. [PMID: 25179299 DOI: 10.1039/c4cp02678k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the thermal oxidation process of nanographene using activated carbon fibers (ACFs) by thermogravimetry (TG), X-ray photoemission spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS), and electrical conductance measurements. The oxidation process started from the edge of nanographene with the formation of phenol (-OH) or ether (C-O-C) groups attached to edge carbon atoms, as verified by the XPS and NEXAFS results. While the TG results indicated a decrease in the size of the nanographene sheet during the oxidation process, the intensity of the edge-state peak, i.e., the signature of the zigzag edge, decreased in the C K-edge NEXAFS spectra. This suggests that the zigzag edge preferentially reacted with oxygen and that the nanographene terminated with the thermodynamically unstable zigzag edges converted to one terminated with stable armchair edges. As the oxidation temperature increased, the activation energy for the electron hopping transport governed by the Coulomb gap variable range hopping between the nanographene sheets increased, and the tunneling barrier decreased. This change can be understood on the basis of the decrease in the size of the nanographene sheets together with the preferential etching of nanographene edges and the decrease in the inter-nanographene-sheet distance.
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Affiliation(s)
- Jun-ichi Takashiro
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
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