10-1
10.
Operation Modes
There are 38 techniques available on the BAS 100B/W. This may appear to be a
bewildering number, but many of these techniques are related, or are variations of
other techniques. There are a number of broad divisions that can be made.
Control Potential
Voltammetry
(I vs. E)
Chronoamperometry
(I vs. t at fixed E)
Hydrodynamic
Pulse Voltammetry
(DPV, SWV, NPV, SCP
,...)
Hydrodynamic
RDE, HDM
Stationary Soln.
Stationary Soln.
Control Potential
Electrolysis
Small Amp
ACV, PSACV, SHACV
Large Amp
CV, LSV
CA
CC
LC/EC
a) Voltammetry vs. chronoamperometry (potential step). In voltammetry, the potential is
varied in a defined manner, and the current response is monitored. In
chronoamperometry, the potential is held at a fixed value (or is stepped between two
values) and the current response is monitored as a function of time.
b) Stationary solution vs. Hydrodynamic. This determines the rate at which electroactive
molecules are brought to the surface of the working electrode (i.e., the rate of mass
transport). In stationary solutions, the only mode of mass transport is diffusion,
whereas in hydrodynamic techniques, there is a combination of convection (e.g.,
stirring) and diffusion. Therefore, in these latter techniques, the rate of mass transport
can be controlled.
There is another set of techniques (pulse techniques) in which the applied potential is
a combination of voltammetry and potential step. This are discussed in more detail
below.
Sweep Techniques (Stationary Solution)
Cyclic Voltammetry (CV)
Linear Sweep Voltammetry (LSV)
Linear Sweep Voltammetry with Log output (LOGI)
Cyclic waveform (CYCLE)
Step Techniques (Stationary Solution)