Spectroelectrochemical flow cell

Applications:

• Study of charge transfer mechanism on the interface between electrode and electrolyte.
• Spectroscopy on electrode surface or in the neighborhood.
• Absorption spectra of products and intermediates.
• Analyses of concentration, diffusion coefficient, life time, and so on.
  
  　Schematic view of flow cell (thin layer flow channel, light pass and working electrode) is shown below. Working electrodes (ITO, platinum mini-grid, and gold mini-grid) are replaceable. UV or visible light is introduced via optical-fiber from light source and the absorbed light is transferred into CCD via optical-fiber. Example of spectrum change during oxidation-reduction of ferrocene by CV is shown below at right.

Spectroelectrochemical electrodes

 

Schematic diagram of spectroelectrochemical flow cell

Pt and Gold mini Grid electrode

Pt mini-grid electrode is made by sputtering on quartz plate as shown in the picture below. Size is 8 × 27 mm, width of grid line is 150 µm, space between lines is 100 µm.

Spectroelectrochemical system with Flow cell kit

Fiber optic spectrometer was used in this measuring system; Lights are transmitted by optic fibers over a proper wavelength through electrode. The lights absorption, which caused by electrolysis on the electrode, can be detected by spectrometer.


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Figure 1. The absorbance of ferrocene and products in acetonitrile with TEAP.
Electrolysis conditions： electrolyzed at 800 ｍV for 400 second　using ITO　working electrode.

 

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Figure 2. The absorbance of potassium hexacyanoferrate (II) and products in KNO₃.
Electrolysis conditions: electrolyzed at 500 mV for 300 second using ITO working electrode.

The change of absorbance due to oxidation/reduction during electrolysis measurement can be observed clearly. When a sample is active spectroscopically and electrochemically, deep understanding of the reaction mechanism can be obtained by analyzing it simultaneously.

 

 

 

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