Sequential and Coupled Proton and Electron Transfer Events in the S2 → S3 Transition of Photosynthetic Water Oxidation Revealed by Time-Resolved X-ray Absorption Spectroscopy

Biochemistry ◽  
2016 ◽  
Vol 55 (50) ◽  
pp. 6996-7004 ◽  
Author(s):  
Ivelina Zaharieva ◽  
Holger Dau ◽  
Michael Haumann
Author(s):  
Chiara Pasquini ◽  
Si Liu ◽  
Petko Chernev ◽  
Diego Gonzalez-Flores ◽  
Mohammad Reza Mohammadi ◽  
...  

AbstractTransition metal oxides are promising electrocatalysts for water oxidation, i.e., the oxygen evolution reaction (OER), which is critical in electrochemical production of non-fossil fuels. The involvement of oxidation state changes of the metal in OER electrocatalysis is increasingly recognized in the literature. Tracing these oxidation states under operation conditions could provide relevant information for performance optimization and development of durable catalysts, but further methodical developments are needed. Here, we propose a strategy to use single-energy X-ray absorption spectroscopy for monitoring metal oxidation-state changes during OER operation with millisecond time resolution. The procedure to obtain time-resolved oxidation state values, using two calibration curves, is explained in detail. We demonstrate the significance of this approach as well as possible sources of data misinterpretation. We conclude that the combination of X-ray absorption spectroscopy with electrochemical techniques allows us to investigate the kinetics of redox transitions and to distinguish the catalytic current from the redox current. Tracking of the oxidation state changes of Co ions in electrodeposited oxide films during cyclic voltammetry in neutral pH electrolyte serves as a proof of principle. Graphical abstract


2004 ◽  
Vol 75 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Melanie Saes ◽  
Frank van Mourik ◽  
Wojciech Gawelda ◽  
Maik Kaiser ◽  
Majed Chergui ◽  
...  

2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Yujin Kim ◽  
Daewoong Nam ◽  
Rory Ma ◽  
Sangsoo Kim ◽  
Myung-jin Kim ◽  
...  

Understanding the ultrafast dynamics of molecules is of fundamental importance. Time-resolved X-ray absorption spectroscopy (TR-XAS) is a powerful spectroscopic technique for unveiling the time-dependent structural and electronic information of molecules that has been widely applied in various fields. Herein, the design and technical achievement of a newly developed experimental apparatus for TR-XAS measurements in the tender X-ray range with X-ray free-electron lasers (XFELs) at the Pohang Accelerator Laboratory XFEL (PAL-XFEL) are described. Femtosecond TR-XAS measurements were conducted at the Ru L 3-edge of well known photosensitizer tris(bipyridine)ruthenium(II) chloride ([Ru(bpy)3]2+) in water. The results indicate ultrafast photoinduced electron transfer from the Ru center to the ligand, which demonstrates that the newly designed setup is applicable for monitoring ultrafast reactions in the femtosecond domain.


2009 ◽  
Vol 96 (1) ◽  
pp. 11-18 ◽  
Author(s):  
G. Gavrila ◽  
K. Godehusen ◽  
C. Weniger ◽  
E. T. J. Nibbering ◽  
T. Elsaesser ◽  
...  

2015 ◽  
Vol 119 (33) ◽  
pp. 19279-19286 ◽  
Author(s):  
Masaaki Yoshida ◽  
Yosuke Mitsutomi ◽  
Takehiro Mineo ◽  
Masanari Nagasaka ◽  
Hayato Yuzawa ◽  
...  

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