Contents Electrochemical Potential Windows

Why now is diamond so attractive to be used as material for electrodes Firstly, it is a very stable material under both mechanic and chemical aspects, so it can even be employed in highly aggressive media. Secondly, it features favorable electrochemical properties like a very wide potential window (see below) and a low background current. Furthermore, it is resistant to the so-called fouling and does not form oxides passivating its surface. Hence it may be employed as a sensor or in electrosynthesis (Section 6.6.3). The low sp -content causes an inert behavior in many media here. For example, high-quality diamond electrodes are stable even in a melt of KCl/LiCl at 450 °C. 

Direct comparison of the electrochemical window of different ILs is difficult for several reasons. Firstly, the reference electrode is different during the measurement of the electrochemical window since some reference electrodes such as Ft and Ag are only quasi reference electrodes and the standard redox potential is difficult to define. Secondly, the working electrodes are usually not the same and the decomposition potentials at different electrode surfaces are not the same. Thirdly, even when the same working and reference electrodes are used, the content of impurities in the IL is uncertain. Electroactive impurities such as halide ions or water significantly reduce the electrochemical stability of ILs. 

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