The Technology of Hot-Wire Electrochemistry

Abstract

The technologic basis for in situ heating of a microelectrode wire by high amplitude, high frequency alternating current (hot-wire electrochemistry) is presented. The preferred modes are continuous heating until a stationary temperature value is established, and pulsed heating with short time current sampling. The latter allows measurement above the boiling point.

The Limits of Aqueous Hot-Wire Electrochemistry: Near-Critical and Supercritical Fluids in Electrochemical Sensors?

“…In every case, as mandatory to all versions of hot-wire electrochemical experiments, electrodes are arranged symmetrically, with an electrical connection to the working electrode terminal of a potentiostat [1]. In every case, as mandatory to all versions of hot-wire electrochemical experiments, electrodes are arranged symmetrically, with an electrical connection to the working electrode terminal of a potentiostat [1].…”

“…According to (1), every value of superheat DW in Kelvin is related to a bubble with de®nite value of r in [m] on the surface, that is in equilibrium with the liquid under this set of conditions [4]. If we consider a homogeneous liquid region surrounding the electrode, we can claim that it should be possible to keep this region homogeneous until supercritical temperatures are reached, if bubble nucleation doesn't occur during the fast temperature rise.…”

Miniaturization of electroanalytical systems

“…One example is voltammetry with in situ generation of temperature variations. This field of research was predominantly influenced by contributions from Gründler's group [3]. On the basis of microwire electrodes heated by AC currents it was demonstrated that local temperature control at microelectrode surfaces can be an effective means to enhance the analytical performance of voltammetric measurements.…”

Microwave enhanced electrochemistry: mass transport effects and steady state voltammetry in the sub-millisecond time domain

“…Grü ndler and coworkers [12,13] have studied and demonstrated the application of hot wire electrodes. Radio-frequency heating has been applied to macroelectrodes in flow cell systems [14,15] and has been shown by Baranski [16] to allow high temperature conditions to be applied at conventional microelectrodes.…”