Interfacial Electrochemical Methods: Overview

In contrast to bulk methods, interfacial electrochemical methods measure the signals produced at the boundary between an electrode and a solution.

These methods are categorized as static or dynamic, depending on whether the cell has a nonzero current.

Static methods, such as potentiometry, involve measuring the cell's potential without any significant current passing through the electrodes, leaving the solution composition within the cell unchanged.

In contrast, dynamic methods involve chemical reactions that change the analyte concentrations and use a nonzero current in the cell. These methods are further divided based on whether the current or the voltage is controlled while the other is varied.

For instance, controlled-current coulometry uses a flow of constant current to either oxidize or reduce the analyte.

Meanwhile, amperometry—a controlled-potential method—monitors the current while maintaining a constant potential that causes the analyte's electrolysis reaction.