Spectroelectrochemistry

Design of a new UV/Vis-spectroelectrochemical measuring system

Poster
(PDF, 82 kB)

01.01.2008 - 31.12.2008

Arbeitsgemeinschaft industrieller Forschungsvereinigungen e.V.

Aims

Electrochemical measuring techniques are used in different areas of chemical research and industry. These methods do not deliver structural information of generated products. Therefore electrochemistry is combined with spectroscopical techniques to obtain structural information.
The aim of this project is to develop a novel electrochemical measuring system for spectroscopical analysis of products formed on rotating disc electrodes.
The project is performed in cooperation with Elektroniklabor Peter Schrems.

Experimental Arrangement

The measuring system consists of a rotating (ring) disc elektrode, a fibre-optic light guide and a motorised positioning unit for the optical part.
The light guide is placed beneath the rotating electrode. The electrode material (preferably platinum or gold) either in the disc or in the ring is used as a mirror to reflect the light. Accurate positioning of the light guide is obtained using the positioning system.
With this system reaction products from the disc can be detected spectroscopically on the ring. They are transported radially to the outside of the electrode.
Corrosion products and precipitation of reaction products can be observed spectroscopically on the disc electrode.

Results

The functionality of the system was verified electrochemically and spectroscopically. Potassium ferrocyanide (K4 [Fe(CN)6 ]) was used as test solution. The pale yellow potassium ferrocyanide (K4 [Fe(CN)6 ]) is oxidized to form orange ferricyanide in front of the electrode.
The resulting changes in absorption in the visible range can be detected spectroscopically . The light guide has to be placed close to the electrode to obtain the best spectroscopic results. Stable spectroscopic signals can be achieved up to 200 revolutions per minute.

Further experiments will be carried out to demonstrate the suitability for studies of electrode kinetics.

Dipl.Ing. Stefanie Hild
Tel.: ++49 69 7564 309
E-mail: Hild