Fundamental Principles of Organic Electrochemistry: Fundamental Aspects of Electrochemistry Dealing with Organic Molecules - Fundamentals and Applications of Organic Electrochemistry - page 4

and gold are good anode materials because of
their higher oxygen overpotential, while
mercury, zinc and lead are good candidates for
cathode materials because of their higher
hydrogen overpotential. However, the toxicity
of mercury has lead to a limited use. On the
other hand, the non-aqueous electrolytes are
stable and their potential windows are generally
larger than those of aqueous electrolytes,
therefore there are few limitations for the
choice of working electrode materials. The most
commonly used working electrode materials for
voltammetry in non-aqueous electrolytes are
platinum, gold and carbon. Although almost all
noble metals can be used as both anode and
cathode materials, base metals are unsuitable
as anode materials because of their dissolution
under anodic polarization.
Various shapes (e.g. disks, wires, plates) and
sizes (e.g. a few square centimetres for plate
electrodes, a few micrometres to a few
centimetres in disk diameter) of solid electrodes
are used for voltammetric measurements
( Figure 2.1 ). Solid electrodes for voltammetric
measurements are most often fabricated by
encapsulating the electrode material in a
non-conducting sheath of glass or inert
polymeric material like Teflon, Kel-F
(poly-chlorotrifluoroethylene) or PEEK
(poly-etheretherketone). Most commonly, the
exposed electrode material is in the form of a
disk ( Figures 2.1a and b ). Common