Monitoring charge transfer at polarisable liquid/liquid interfaces employing time-resolved Raman spectroelectrochemistry

•A new four electrode cell for Raman spectroelectrochemistry at ITIES is developed.•Real-time Raman spectra during ion and electron transfer at ITIES are obtained.•The aqueous side of the interface or the organic side can be sampled.•A clear correlation between spectroscopic and electrochemical responses is observed.

In-situ Raman spectroscopy is implemented for the first time to monitor dynamic charge transfer processes at polarisable interfaces between two immiscible electrolyte solutions (ITIES) in real time. A custom-designed new electrochemical cell is described which allows probing the Raman signals of ferroin ions as a function of the potential applied across the water|1,2-dichlorobenzene (DCB) interface. This approach is also used for investigating the heterogeneous electron transfer reaction involving dimethylferrocene in DCB and potassium hexacyanoferrate (II/III) in the aqueous phase. The evolution of the Raman signals during potentiodynamic measurements is recorded in real-time with a resolution of a few seconds.