Fundamental Principles of Organic Electrochemistry: Fundamental Aspects of Electrochemistry Dealing with Organic Molecules - Fundamentals and Applications of Organic Electrochemistry - page 12

2.5 Cells and Power Sources
The most important decision to be made in
planning voltammetry is whether to use an
undivided cell, in which the working, auxiliary
and reference electrodes are immersed in a
single chamber ( Figure 2.3a ), or a divided cell,
in which the working and auxiliary electrodes
are in separate compartments ( Figure 2.3b ) [6].
In making this decision, we have to consider
interference by electrolysis products at the
auxiliary electrode in voltammetric
experiments. If this happens a divided cell must
be used. When the aqueous reference electrode,
such as an Ag/AgCl electrode or SCE, is used in
non-aqueous systems the reference electrode is
also in a separate compartment in order to
prevent contamination with water ( Figure
2.3c ), as mentioned in section 2.2. In this case,
a salt bridge is used for the ion-conducting
connection between the working electrode and
reference electrode compartments, and the tip
of the salt bridge is dipped into the
non-aqueous solution. In addition, the tip
should be as close as possible to the working
electrode to minimize the iR drop between the
tip and the electrode.
A potentiostat is used as a power supply and is
fundamental to voltammetry using
three-electrode systems [6]. In addition, a wave
generator is necessary for the non-steady state
measurements like cyclic voltammetry (CV).