Voltammetry under a Controlled Temperature Gradient

Abstract

Electrochemical measurements are generally done under isothermal conditions. Here we report on the application of a controlled temperature gradient between the working electrode surface and the solution. Using electrochemical sensors prepared on ceramic materials with extremely high specific heat conductivity, the temperature gradient between the electrode and solution was applied here as a second driving force. This application of the Soret phenomenon increases the mass transfer in the Nernst layer and enables more accurate control of the electrode response enhancement by a combination of diffusion and thermal diffusion. We have thus studied the effect of Soret phenomenon by cyclic voltammetry measurements in ferro/ferricyanide. The time dependence of sensor response disappears when applying the Soret phenomenon, and the complicated shape of the cyclic voltammogram is replaced by a simple exponential curve. We have derived the Cotrell-Soret equation describing the steady-state response with an applied temperature difference.

Enhancement of Electrocatalytic Oxidation of Glycerol by Plasmonics

“…Krejci et al. showed that when the electrode surface is at a higher temperature than the solution (i. e., a temperature gradient exists), mass transfer in the Nernst layer is increased . Experimentally this leads to a sigmoidal CV rather than the classic shape with the diffusional tail typically observed for a redox species in stagnant solution with a macroelectrode.…”

Screen printed electrodes improve mass transfer

“…3). Corruption of this condition leads to hydrodynamic instability (Sajdlová, 2010). The electrical connection on the opposite end is made by the means of a brush contact.…”

“…It can be used for elimination of cross talk of array of electrodes (Dock et al, 2005;Sajdlová, 2010). …”

“…The cell TC1 was placed in a small thermostat TK-1 (KEVA, Czech Republic). The whole system schematic is shown in figure 8 (Krejci et al, 2010). CV is the most common electrochemical method used to investigate the electrochemical behaviour of an analyte.…”

“…These results are used not only in Levich's derivation but in many recent works. Comprehensive analysis of RDE principle is in literature (Sajdlová, 2010;King et al, 2005). An example of a RDE is shown in fig.…”