Advances in Diffraction Studies of Light-Induced Transient Species in Molecular Crystals and Selected Complementary Techniques

The review provides a summary of the current methods of tracing photoexcitation processes and structural dynamics in the solid state, putting major emphasis on the X-ray diffraction techniques (time-resolved Laue diffraction on synchrotron sources and time-resolved serial femtosecond crystallography on X-ray free-electron lasers). The recent developments and nowadays experimental possibilities in the field are discussed along with the data processing and analysis approaches, and illustrated with some striking literature examples of the respective successful studies. Selected complementary methods, such as ultrafast electron diffraction or time-resolved X-ray absorption spectroscopy, are briefly presented.

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Pump-Probe Time-Resolved Serial Femtosecond Crystallography at X-Ray Free Electron Lasers

Crystals ◽

10.3390/cryst10070628 ◽

2020 ◽

Vol 10 (7) ◽

pp. 628

Author(s):

Suraj Pandey ◽

Ishwor Poudyal ◽

Tek Narsingh Malla

Keyword(s):

Free Electron ◽

Reaction Dynamics ◽

Reaction Coordinate ◽

Biological Macromolecules ◽

Free Electron Lasers ◽

Time Resolved ◽

Pump Probe ◽

X Ray ◽

Recent Developments ◽

Serial Femtosecond Crystallography

With time-resolved crystallography (TRX), it is possible to follow the reaction dynamics in biological macromolecules by investigating the structure of transient states along the reaction coordinate. X-ray free electron lasers (XFELs) have enabled TRX experiments on previously uncharted femtosecond timescales. Here, we review the recent developments, opportunities, and challenges of pump-probe TRX at XFELs.

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(Invited) Investigation of the Reaction & Degradation Mechanism of Iron Based Cathodes for Sodium-Ion Batteries Using X-Ray Absorption and Time-Resolved X-Ray Diffraction Techniques

ECS Meeting Abstracts ◽

10.1149/ma2016-02/6/921 ◽

2016 ◽

Keyword(s):

Degradation Mechanism ◽

Sodium Ion ◽

Sodium Ion Batteries ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray ◽

Iron Based ◽

X Ray Absorption

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X-Ray Absorption Spectroscopy as an in-situ Tool in Materials Science

MRS Proceedings ◽

10.1557/proc-502-127 ◽

1997 ◽

Vol 502 ◽

Author(s):

T. Ressler ◽

Joe Wong ◽

W. Metz

Keyword(s):

Absorption Spectroscopy ◽

Materials Science ◽

Ex Situ ◽

Structural Studies ◽

Time Resolved ◽

X Ray ◽

Complementary Techniques ◽

X Ray Absorption ◽

Established Technique

ABSTRACTIn addition to being an established technique for ex-situ structural studies, x-ray absorption spectroscopy (XAS) has recently been realized to be a powerful tool for in-situ time-resolved investigations in materials science. This paper describes two complementary techniques: quick-scanning EXAFS (QEXAFS) and energy-dispersive XAS (DXAS) which offer time resolution in the seconds and milliseconds range, respectively. Formation of a heterogeneous catalyst from a solid-state reaction of a precursor is presented as an example of a time-resolved XAS application.

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A dispenser–reactor apparatus applied forin situXAS monitoring of Pt nanoparticle formation

Journal of Synchrotron Radiation ◽

10.1107/s1600577515003434 ◽

2015 ◽

Vol 22 (3) ◽

pp. 736-744 ◽

Cited By ~ 7

Author(s):

Jocenir Boita ◽

Marcus Vinicius Castegnaro ◽

Maria do Carmo Martins Alves ◽

Jonder Morais

Keyword(s):

Photoelectron Spectroscopy ◽

Metallic Nanoparticles ◽

Pt Nanoparticles ◽

Lattice Parameter ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray ◽

Two Stages ◽

X Ray Absorption

In situtime-resolved X-ray absorption spectroscopy (XAS) measurements collected at the PtL3-edge during the synthesis of Pt nanoparticles (NPs) in aqueous solution are reported. A specially designed dispenser–reactor apparatus allowed for monitoring changes in the XAS spectra from the earliest moments of Pt ions in solution until the formation of metallic nanoparticles with a mean diameter of 4.9 ± 1.1 nm. By monitoring the changes in the local chemical environment of the Pt atoms in real time, it was possible to observe that the NPs formation kinetics involved two stages: a reduction-nucleation burst followed by a slow growth and stabilization of NPs. Subsequently, the synthesized Pt NPs were supported on activated carbon and characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The supported Pt NPs remained in the metallic chemical state and with a reduced size, presenting slight lattice parameter contraction in comparison with the bulk Pt values.

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Properties of Pure and Sulfided NiMoO4 and CoMoO4 Catalysts: Tpr, Xanes and Time-Resolved XRD Studdzs

MRS Proceedings ◽

10.1557/proc-497-41 ◽

1997 ◽

Vol 497 ◽

Author(s):

S. Chaturvedi ◽

J. A. Rodriguez ◽

J. C. Hanson ◽

A. Albornoz ◽

J. L. Brito

Keyword(s):

Electronic Properties ◽

X Ray Diffraction ◽

Time Resolved ◽

Direct Transformation ◽

X Ray ◽

Β Phase ◽

Structural And Electronic Properties ◽

X Ray Absorption ◽

Kinetics Of ◽

Cobalt And Nickel

ABSTRACTX-ray absorption near-edge spectroscopy (XANES) was used to characterize the structural and electronic properties of a series of cobalt- and nickel-molybdate catalysts (AMoO4.nH20, α-AMoO4, β-AMoO4; A= Co or Ni). The results of XANES indicate that the Co and Ni atoms are in octahedral sites in all these compounds, while the coordination of Mo varies from octahedral in the a-phases to tetrahedral in the β-phases and hydrate. Time-resolved x-ray diffraction shows a direct transformation of the hydrates into the β-AMoO4 compounds (following a kinetics of first order) at temperatures between 200 and 350 °C. This is facilitated by the similarities that the AMoO4.nH20 and β-AMoO4 compounds have in their structural and electronic properties. The molybdates react with H 2 at temperatures between 400 and 600 °C, forming gaseous water and oxides in which the oxidation state of Co and Ni remains +2 while that of Mo is reduced to +5 or +4. After exposing α-NiMoO4 and P-NiMoO4 to H2S, both metals get sulfided and a NiMoSx phase is formed. For the β phase of NiMoO4 the sulfidation of Mo is more extensive than for the a phase, making the former a better precursor for catalysts of hydrodesulfurization reactions.

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Phase Transition Analysis between LiFePO4and FePO4by In-Situ Time-Resolved X-ray Absorption and X-ray Diffraction

Journal of The Electrochemical Society ◽

10.1149/2.012305jes ◽

2013 ◽

Vol 160 (5) ◽

pp. A3061-A3065 ◽

Cited By ~ 33

Author(s):

Yuki Orikasa ◽

Takehiro Maeda ◽

Yukinori Koyama ◽

Taketoshi Minato ◽

Haruno Murayama ◽

...

Keyword(s):

Phase Transition ◽

X Ray Diffraction ◽

Transition Analysis ◽

Time Resolved ◽

X Ray ◽

X Ray Absorption

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Expanding the Mechanochemical Toolbox: Combining X-Ray Absorption Spectroscopy and Scattering for in Situ Time-Resolved Monitoring of Gold Nanoparticle Mechanosynthesis

10.26434/chemrxiv.12290756 ◽

2020 ◽

Author(s):

Paulo F M de Oliveira ◽

Adam Michalchuk ◽

Ana de Oliveira Guilherme Buzanich ◽

Ralf Bienert ◽

Roberto M. Torresi ◽

...

Keyword(s):

Absorption Spectroscopy ◽

Electronic Materials ◽

Early Stage ◽

X Ray Diffraction ◽

Time Resolved ◽

Subsequent Formation ◽

X Ray ◽

Detection Capabilities ◽

X Ray Absorption

<div>The development of time-resolved in situ approaches for monitoring mechanochemical</div><div>transformations has revolutionized the field of mechanochemistry. Currently, the established in</div><div>situ approaches greatly limit the scope of investigations that are possible. Here we develop a new</div><div>approach to simultaneously follow the evolution of bulk atomic and electronic structure during a</div><div>mechanochemical synthesis. This is achieved by coupling two complementary synchrotron-based</div><div>X-ray methods: X-ray absorption spectroscopy and X-ray diffraction. We apply this method to</div><div>investigate the bottom-up mechanosynthesis of technologically important Au nanoparticles in the</div><div>presence of three different reducing agents. Moreover, we demonstrate how X-ray absorption</div><div>spectroscopy offers unprecedented insight into the early stage generation of growth species (e.g.</div><div>monomers and clusters), which lead to the subsequent formation of nanoparticles. These</div><div>processes are beyond the detection capabilities of diffraction methods. The approach is general,</div><div>and not limited to monitoring NP mechanosynthesis. This combined X-ray approach paves the</div><div>way to new directions in mechanochemical research of advanced electronic materials.</div>

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Electrochemical Oxidation and Reduction Processes of Platinum Nanoparticles Probed by Time-resolved High-energy X-ray Diffraction and X-ray Absorption Spectroscopy

ECS Meeting Abstracts ◽

10.1149/ma2006-01/5/302 ◽

2006 ◽

Keyword(s):

Electrochemical Oxidation ◽

Absorption Spectroscopy ◽

Platinum Nanoparticles ◽

High Energy ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray ◽

Reduction Processes ◽

X Ray Absorption

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A reaction cell for time-resolvedin situXAS studies during wet chemical synthesis: the Cu2(OH)3Cl case

Journal of Synchrotron Radiation ◽

10.1107/s1600577513028786 ◽

2013 ◽

Vol 21 (1) ◽

pp. 254-258 ◽

Cited By ~ 9

Author(s):

Jocenir Boita ◽

Maria do Carmo Martins Alves ◽

Jonder Morais

Keyword(s):

Chemical Synthesis ◽

Photoelectron Spectroscopy ◽

X Ray Diffraction ◽

Reaction Cell ◽

Time Resolved ◽

X Ray ◽

Wet Chemical Synthesis ◽

X Ray Absorption ◽

Electronic And Structural Properties

The use ofin situtime-resolved dispersive X-ray absorption spectroscopy (DXAS) to monitor the formation of Cu2(OH)3Cl particles in an aqueous solution is reported. The measurements were performed using a dedicated reaction cell, which enabled the evolution of the CuK-edge X-ray absorption near-edge spectroscopy to be followed during mild chemical synthesis. The formed Cu2(OH)3Cl particles were also characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. The influence of polyvinylpyrrolidone (PVP) on the electronic and structural properties of the formed particles was investigated. The results indicate clearly the formation of Cu2(OH)3Cl, with or without the use of PVP, which presents very similar crystalline structures in the long-range order. However, depending on the reaction, dramatic differences were observed byin situDXAS in the vicinities of the Cu atoms.

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