scholarly journals Characterization of the Electrochemical Reactions in the Li1+xV3O8/Li Cell by Soft X-ray Absorption Spectroscopy and Two-Dimensional Correlation Analysis

2003 ◽  
Vol 57 (8) ◽  
pp. 984-990 ◽  
Author(s):  
Hyun Chul Choi ◽  
Young Mee Jung ◽  
Seung Bin Kim
Keyword(s):  
Correlation Analysis ◽  
Absorption Spectroscopy ◽  
Extraction Process ◽  
Electrochemical Reactions ◽  
Lithium Content ◽  
Spectral Features ◽  
Two Dimensional ◽  
X Ray ◽  
X Ray Absorption ◽  
2D Correlation Analysis

We applied soft X-ray absorption spectroscopy (XAS) and two-dimensional (2D) correlation analysis to the first lithium insertion–extraction cycle in a Li1+xV3O8/Li cell in order to investigate the electrochemical reactions of lithium with the Li1+xV3O8 electrode. The V LII,III-edge and O K-edge spectra of the Li1+xV3O8 electrode were obtained for varying electrode lithium content. The insertion of lithium leads to the reduction of the V5+ species present in the pristine Li1+xV3O8 electrode, and to the red shift and the broadening of the spectral features of the V LII,III edge compared to those of the pristine electrode. In the extraction process, the main spectral features at the highest value of the extraction of lithium show some differences compared to the features of the pristine electrode spectrum due to the residual lithium ions in the Li1+xV3O8 structure. The O K-edge spectra revealed that the insertion of lithium mainly affects the V 4sp–O 2p bonds and consequently induces a change in bonding geometry. The 2D correlation analysis of these spectra clearly shows that V–O bonds are significantly perturbed by the insertion–extraction of lithium into the Li1+xV3O8 electrode.

Application of the Generalized 2D Correlation Analysis to Dynamic Near-Edge X-ray Absorption Spectroscopy Data

2005 ◽  
Vol 127 (6) ◽  
pp. 1906-1912 ◽  
Author(s):  
Peter Haider ◽  
Yuan Chen ◽  
Sangyun Lim ◽  
Gary L. Haller ◽  
Lisa Pfefferle ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Absorption Spectroscopy ◽  
Spectroscopy Data ◽  
X Ray ◽  
X Ray Absorption ◽  
2D Correlation Analysis

Recovery of nanosize zinc from phosphor wastes with an ionic liquid

2009 ◽  
Vol 6 (3) ◽  
pp. 268 ◽  
Author(s):  
Hsin-Liang Huang ◽  
H. Paul Wang ◽  
Edward M. Eyring ◽  
Juu-En Chang
Keyword(s):  
Ionic Liquid ◽  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Bond Distance ◽  
Extraction Process ◽  
Room Temperature Ionic Liquid ◽  
Zns Nanoparticles ◽  
Recovery Method ◽  
X Ray ◽  
X Ray Absorption

Environmental context. Very fine phosphor ashes are discharged from particulate collection systems (such as bag houses) in the cathode ray tube or television disassembling processes. Effective recovery of ZnO and ZnS nanoparticles from the phosphor ash can be achieved by extraction with a room temperature ionic liquid. By synchrotron radiation X-ray absorption spectroscopy, the obtained molecular scale data turn out to be very useful in revealing speciation of zinc in the extraction process, which also facilitates the development of a simple nanoparticle recovery method. Abstract. An effective, simple method has been developed for the recovery of ZnO and ZnS nanoparticles from hazardous phosphor ash waste. Experimentally, zinc (77%) in the phosphor ash (that contains mainly zinc (91%)) can be recovered by extraction with a room temperature ionic liquid (RTIL) ([C4mim][PF6], 1-butyl-3-methylimidazolium hexafluorophosphate). Component fitted X-ray absorption near edge structure (XANES) spectra of zinc indicate that metallic zinc (Zn) (9%) in the phosphor ash can be dissolved to form a Zn2+–1-methylimidazole ([mim]) complex during extraction with the RTIL. ZnS and ZnO nanoparticles (60–61%) can also be extracted from the phosphor. Over the 298–523 K temperature range, desired ZnO/ZnS ratios (0.3–0.6) can be obtained since interconversion of ZnS to ZnO in the RTIL is temperature dependent. The Fourier transformed extended X-ray absorption fine structure (EXAFS) data also show that the nanosize ZnS extracted in the RTIL possesses a Zn–S bond distance of 2.33 Å with coordination numbers (CNs) of 3.6–3.7. At 523 K, in the RTIL, ~30% of the ZnS is oxidised to form octahedral ZnO (with a bond distance of 2.10 Å and a CN of 6.1) that may coat the surfaces of the ZnS nanoparticles. This work exemplifies the utilisation of X-ray absorption spectroscopy (EXAFS and XANES) to reveal speciation and possible reaction pathways in a nanoparticle extraction process (with a RTIL) in detail.

Cation Extraction Process in Bilayer Cyanide Film as Investigated by Depth-Resolved X-ray Absorption Spectroscopy

2011 ◽  
Vol 50 (12R) ◽  
pp. 125802
Author(s):  
Ayako Omura ◽  
Yutaro Kurihara ◽  
Tomoyuki Matsuda ◽  
Hajime Tanida ◽  
Tomoya Uruga ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Extraction Process ◽  
X Ray ◽  
X Ray Absorption ◽  
Cation Extraction

scholarly journals Rate Constants of Electrochemical Reactions in a Lithium-Sulfur Cell Determined by Operando X-ray Absorption Spectroscopy

2018 ◽  
Vol 165 (14) ◽  
pp. A3487-A3495 ◽  
Author(s):  
Dunyang Rita Wang ◽  
Deep B. Shah ◽  
Jacqueline A. Maslyn ◽  
Whitney S. Loo ◽  
Kevin H. Wujcik ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Rate Constants ◽  
Electrochemical Reactions ◽  
X Ray ◽  
X Ray Absorption ◽  
Lithium Sulfur

ELECTRONIC STRUCTURES OF La0.7Ca0.3MnO3 AND La0.7Ce0.3MnO3 BY X-RAY ABSORPTION SPECTROSCOPY

2002 ◽  
Vol 09 (02) ◽  
pp. 1053-1057 ◽  
Author(s):  
K. ASOKAN ◽  
K. V. R. RAO ◽  
J. C. JAN ◽  
J. W. CHIOU ◽  
W. F. PONG ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Electronic Structures ◽  
Spectral Features ◽  
Electron Hole ◽  
Edge Structure ◽  
X Ray ◽  
Strong Hybridization ◽  
Doped Manganites ◽  
X Ray Absorption ◽  
Tetravalent State

Electronic structures of hole-doped and electron hole-doped manganites, La 0.7 Ca 0.3 MnO 3 and La 0.7 Ce 0.3 MnO 3, have been elucidated by X-ray absorption near-edge structure (XANES) spectra of O K- and Mn L3,2-edges. In the electron-doped system, La 0.7 Ce 0.3 MnO 3, the spectral features of O K-edge spectra are shifted by ~ 1 eV towards the higher energy side and reduction of Mn valency from 4+ and 3+ to 3+ and 2+ is expected when compared to hole-doped manganite. The XANES of Ce M5,4-edges indicates a tetravalent state for Ce, similar to that in CeO 2. Ce 4+ is incorporated into the lattice of LaMnO 3, resulting in the modification of MnO 6 octahedra and also indicating strong hybridization of Ce 5d and/or Ce 4f states with O 2p states.

Cation Extraction Process in Bilayer Cyanide Film as Investigated by Depth-Resolved X-ray Absorption Spectroscopy

2011 ◽  
Vol 50 ◽  
pp. 125802 ◽  
Author(s):  
Ayako Omura ◽  
Yutaro Kurihara ◽  
Tomoyuki Matsuda ◽  
Hajime Tanida ◽  
Tomoya Uruga ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Extraction Process ◽  
X Ray ◽  
X Ray Absorption ◽  
Cation Extraction

New Approach to Avoid Erroneous Interpretation of Results Derived from Generalized Two-Dimensional Correlation Analysis for Applications in Catalysis

2005 ◽  
Vol 59 (8) ◽  
pp. 1060-1067 ◽  
Author(s):  
Peter Haider ◽  
Gary L. Haller ◽  
Lisa Pfefferle ◽  
Dragos Ciuparu
Keyword(s):  
Correlation Analysis ◽  
Surface Characterization ◽  
Oscillatory Behavior ◽  
Data Matrix ◽  
Spectral Features ◽  
Two Dimensional ◽  
New Approach ◽  
Set Up ◽  
Time Sequences ◽  
2D Correlation Analysis

Surface characterization and catalysis can significantly benefit from the application of generalized two-dimensional (2D) correlation analysis. This two-dimensional approach allows a better resolution of overlapping peaks, can reveal new features not readily observable in the raw spectra, gives clear evidence for spectral intensities that change as an effect of a perturbation applied to the system, and allows the establishment of time sequences for the changes occurring in different spectral features of interest for determining reaction intermediates and/or mechanisms. The interpretation of the synchronous and asynchronous plots was observed to lead to erroneous time sequences when spectral features change in a nonmonotonic way, such as a biphasic or oscillatory behavior, under the influence of a perturbation. We propose a new approach to the 2D correlation analysis to avoid misinterpretation of the results calculated in the asynchronous plot. Progressive correlation analysis (ProCorA) calculates the synchronous plot from the first two spectra of the data matrix and one spectrum is added at every step of the analysis. The sequence of changes can be set up from the progressive evolution of peaks in both the synchronous and asynchronous plots.

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