Electrochemical Methods

Voltammetry / Cyclovoltammety

In voltammetry (volt-amperometry), a qualitative and quantitative analysis of a sample is carried out during electrolysis or electrochemical reactions using a current-voltage curve. This is based on oxidation or reduction processes at substance-specific voltages. These oxidation or reduction processes are determined by a change in the current, the level of which is proportional to the concentration of reacted compounds.

In cyclic voltammetry or cyclic voltammetry, the applied voltage is first increased and then decreased again.

Contact person: Hans-Dieter Schmidt

Amperometry

In amperometry, an electrochemically induced current is measured. In amperometry, a constant voltage is applied over time. The measured current is proportional to the concentration of the converted substance. A typical application example is the Clark electrode, which is used to determine the oxygen concentration.

Contact person: Hans-Dieter Schmidt

Coulometry

Coulometry is based on the conversion of charges through the oxidation or reduction of substances in an electrolytic cell. By determining the amount of charge, it is possible to draw conclusions about the quantity or concentration of the substance. Typical applications are, for example, the determination of water content using coulometric Karl Fischer titration or the quantification of adsorbable organically bound halogens.

Contact person: Hans-Dieter Schmidt

Electrochemical Impedance Spectroscopy

Electrochemical impedance spectroscopy (EIS) is a method in which an alternating current is applied to a sample system (usually a sample in combination with a medium). During the experiment, the resistance of the system is determined as a function of frequency. With the help of suitable equivalent circuit diagrams, important properties such as corrosion resistances or film or diffusion properties can then be characterized. Furthermore, electrochemical impedance spectroscopy is also used to characterize batteries, fuel cells or semiconductor elements.

Contact person: Hans-Dieter Schmidt

Kurven einer elektrochemischen Impedanz-Messung