Insight into growth of Au–Pt bimetallic nanoparticles: anin situXAS study

2017 ◽  
Vol 24 (4) ◽  
pp. 825-835 ◽  
Author(s):  
Chandrani Nayak ◽  
D. Bhattacharyya ◽  
K. Bhattacharyya ◽  
A. K. Tripathi ◽  
R. D. Bapat ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Energy Dispersive ◽  
Core Shell ◽  
One Pot ◽  
X Ray ◽  
The Core ◽  
One Pot Synthesis ◽  
X Ray Absorption ◽  
Insight Into

Au–Pt bimetallic nanoparticles have been synthesized through a one-pot synthesis route from their respective chloride precursors using block copolymer as a stabilizer. Growth of the nanoparticles has been studied by simultaneousin situmeasurement of X-ray absorption spectroscopy (XAS) and UV–Vis spectroscopy at the energy-dispersive EXAFS beamline (BL-08) at Indus-2 SRS at RRCAT, Indore, India.In situXAS spectra, comprising both X-ray near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) parts, have been measured simultaneously at the Au and PtL3-edges. While the XANES spectra of the precursors provide real-time information on the reduction process, the EXAFS spectra reveal the structure of the clusters formed in the intermediate stages of growth. This insight into the formation process throws light on how the difference in the reduction potential of the two precursors could be used to obtain the core–shell-type configuration of a bimetallic alloy in a one-pot synthesis method. The core–shell-type structure of the nanoparticles has also been confirmed byex situenergy-dispersive spectroscopy line-scan and X-ray photoelectron spectroscopy measurements within situion etching on fully formed nanoparticles.

Ru-core/Cu-shell bimetallic nanoparticles with controlled size formed in one-pot synthesis

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 14856-14862 ◽  
Author(s):  
I. Helgadottir ◽  
G. Freychet ◽  
P. Arquillière ◽  
M. Maret ◽  
P. Gergaud ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Small Angle ◽  
Bimetallic Nanoparticles ◽  
Organometallic Compounds ◽  
Core Shell ◽  
One Pot ◽  
X Ray ◽  
The Core ◽  
X Ray Scattering ◽  
Core Shell Structure

Anomalous Small-Angle X-ray Scattering (ASAXS) experiments attest the core-shell structure of bimetallic nanoparticles Ru and Cu, synthesized by simultaneous decomposition of two organometallic compounds in an ionic liquid.

In situ time resolved studies of hydride and deuteride formation in Pd/C electrodes via energy dispersive X-ray absorption spectroscopy

2005 ◽  
Vol 7 (2) ◽  
pp. 366-372 ◽  
Author(s):  
A. Rose ◽  
O. South ◽  
I. Harvey ◽  
S. Diaz-Moreno ◽  
J. R. Owen ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Energy Dispersive ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Absorption

In Situ X-ray Absorption Spectroscopy/Energy-Dispersive X-ray Diffraction Studies on the Hydrothermal Formation of Bi2W1-xMoxO6 Nanomaterials

2012 ◽  
Vol 2012 (5) ◽  
pp. 783-789 ◽  
Author(s):  
Ying Zhou ◽  
Elena Antonova ◽  
Yuanhua Lin ◽  
Jan-Dierk Grunwaldt ◽  
Wolfgang Bensch ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption

scholarly journals In-Situ Synchrotron SAXS and WAXS Investigation on the Deformation of Single and Coaxial Electrospun P(VDF-TrFE)-Based Nanofibers

2021 ◽  
Vol 22 (23) ◽  
pp. 12669
Author(s):  
Yi-Jen Huang ◽  
Yi-Fan Chen ◽  
Po-Han Hsiao ◽  
Tu-Ngoc Lam ◽  
Wen-Ching Ko ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Electrospun Nanofibers ◽  
Mechanical Anisotropy ◽  
Core Shell ◽  
Length Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Nanofiber Alignment

Coaxial core/shell electrospun nanofibers consisting of ferroelectric P(VDF-TrFE) and relaxor ferroelectric P(VDF-TrFE-CTFE) are tailor-made with hierarchical structures to modulate their mechanical properties with respect to their constituents. Compared with two single and the other coaxial membranes prepared in the research, the core/shell-TrFE/CTFE membrane shows a more prominent mechanical anisotropy between revolving direction (RD) and cross direction (CD) associated with improved resistance to tensile stress for the crystallite phase stability and good strength-ductility balance. This is due to the better degree of core/shell-TrFE-CTFE nanofiber alignment and the crystalline/amorphous ratio. The coupling between terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for phase stabilization, comparing the core/shell-TrFE/CTFE with the pristine terpolymer. Moreover, an impressive collective deformation mechanism of a two-length scale in the core/shell composite structure is found. We apply in-situ synchrotron X-ray to resolve the two-length scale simultaneously by using the small-angle X-ray scattering to characterize the nanofibers and the wide-angle X-ray diffraction to identify the phase transformations. Our findings may serve as guidelines for the fabrication of the electrospun nanofibers used as membranes-based electroactive polymers.

In situ studies of the dehydration of zeolitic catalysts by time-resolved energy-dispersive x-ray absorption spectroscopy

1990 ◽  
Vol 94 (17) ◽  
pp. 6517-6519 ◽  
Author(s):  
J. W. Couves ◽  
J. M. Thomas ◽  
C. R. A. Catlow ◽  
G. N. Greaves ◽  
G. Baker ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Energy Dispersive ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Studies ◽  
X Ray Absorption

In Situ Time-Resolved Energy-Dispersive X-ray Absorption Fine Structure Study on the Decarbonylation Processes of Mo(CO)6Entrapped in NaY and HY Zeolites

2002 ◽  
Vol 106 (9) ◽  
pp. 2415-2422 ◽  
Author(s):  
Aritomo Yamaguchi ◽  
Akane Suzuki ◽  
Takafumi Shido ◽  
Yasuhiro Inada ◽  
Kiyotaka Asakura ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
Energy Dispersive ◽  
Time Resolved ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
Hy Zeolites

scholarly journals Unraveling the Core–Shell Structure of Ligand-Capped Sn/SnOxNanoparticles by Surface-Enhanced Nuclear Magnetic Resonance, Mössbauer, and X-ray Absorption Spectroscopies

ACS Nano ◽  
2014 ◽  
Vol 8 (3) ◽  
pp. 2639-2648 ◽  
Author(s):  
Loredana Protesescu ◽  
Aaron J. Rossini ◽  
Dominik Kriegner ◽  
Maxence Valla ◽  
Antoine de Kergommeaux ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray ◽  
The Core ◽  
Surface Enhanced ◽  
Core Shell Structure ◽  
X Ray Absorption ◽  
Nuclear Magnetic

X-ray absorption spectroscopy studies of phase transformations and amorphicity in nanotitania powder and silica–titania core–shell photocatalysts

2008 ◽  
Vol 41 (6) ◽  
pp. 1009-1018 ◽  
Author(s):  
S. H. Lim ◽  
N. Phonthammachai ◽  
T. Liu ◽  
T. J. White
Keyword(s):  
Absorption Spectroscopy ◽  
Sol Gel ◽  
Local Environment ◽  
Core Shell ◽  
Transformation Mechanism ◽  
X Ray ◽  
Amorphous Content ◽  
Silica Substrate ◽  
The Core ◽  
X Ray Absorption

The local environment of titanium in nanocrystalline sol-gel synthesized titania, cobaltiferous titania and silica–titania core–shell photocatalysts was investigated using X-ray absorption spectroscopy (XAS). Anatase reconstructively transforms to rutileviaa persistent amorphous phase that is retained, in part, up to 1273 K. In nanotitania, temperature-dependent trends in Ti order correlation observed by XAS parallel the development of amorphous content extracted from powder X-ray diffraction patterns, such that amorphicity shows a transient maximum at ∼873 K with the onset of rutile crystallization. Cobaltiferous and core–shell materials behaved similarly, but with anatase retained to 973 and 1273 K, respectively. In the former, cobalt redox reactions may stabilize anatase to higher temperatures by ready charge-balancing during the loss of hydroxyl and the formation of oxygen vacancies. In the core–shell architecture, higher Ti coordination and interatomic distance variance in the first- and second-nearest-neighbour shells are maintained to 1273 K by interaction of a substantially aperiodic TiO6network with the glassy silica substrate, which inhibits crystallization of rutile from the amorphous intermediate. Comparisons are also drawn with the commercial P25 catalyst. The overall transformation mechanism can be summarized as gel → non-stoichiometric anatase → amorphous titania → rutile. Smaller anatase crystals and a higher average Ti—Ti coordination environment in the core–shell structure may enhance photocatalytic activity directly, by creating larger specific surface areas and hosting reactive defects, or indirectly, by inhibiting exciton annihilation in aperiodic titania and delaying the crystallization of less photoactive rutile.

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