Redox state and photoreduction control using X‐ray spectroelectrochemical techniques – advances in design and fabrication through additive engineering. (28th January 2021)

• Record Type: Journal Article
• Authors: Best, Stephen Peter; Streltsov, Victor A.; Chantler, Christopher Thomas; Li, Wangzhe; Ash, Philip A.; Hayama, Shusaku; Diaz-Moreno, Sofia
• Is Part Of: Journal of synchrotron radiation. Volume 28:Part 2(2021)
• Page Start: 472
• Page End: 479
• Publication Date: 2021-01-28
• Subjects: XAS -- XANES -- electrochemistry -- spectroelectrochemistry -- photoreduction -- copper complexes -- additive engineering; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577520016021
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : The design and operation of a 3D‐printed flow in situ electrochemical cell suitable for ambient‐temperature X‐ray absorption spectra measurements is described. The ability to control, and significantly limit, photoreduction whilst requiring only small solution volumes make this a superior sampling approach to cryogenic techniques for many samples. Abstract : The design and performance of an electrochemical cell and solution flow system optimized for the collection of X‐ray absorption spectra from solutions of species sensitive to photodamage is described. A combination of 3D CAD and 3D printing techniques facilitates highly optimized design with low unit cost and short production time. Precise control of the solution flow is critical to both minimizing the volume of solution needed and minimizing the photodamage that occurs during data acquisition. The details of an integrated four‐syringe stepper‐motor‐driven pump and associated software are described. It is shown that combined electrochemical and flow control can allow repeated measurement of a defined volume of solution, 100 µl, of samples sensitive to photoreduction without significant change to the X‐ray absorption near‐edge structure and is demonstrated by measurements of copper(II) complexes. The flow in situ electrochemical cell allows the collection of high‐quality X‐ray spectral measurements both in the near‐edge region and over an extended energy region as is needed for structural analysis from solution samples. This approach provides control over photodamage at a level at least comparable with that achieved using cryogenic techniques and at the same time eliminates problems associated with interference due to Bragg peaks.