Spectroelectrochemical measurementsLatest updated: October 7, 2019
One of the possibilities of characterizing intermediate species created during a redox process, is to couple a spectrometer with a potentiostat.
Different types of spectrometer can be used for this purpose, in accordance with the intrinsic properties of the intermediate species: UV-Vis, IR, Raman, fluorescence, NMR, EPR, XRD, etc.
However, to detect a species’ very short lifetime, the measurement has to be carried out in situ or in operando conditions.
What’s the difference between in situ and in operando characterisation?
In both cases, electrochemical instruments are used to induce a change, and the spectrometer is used to characterize said change.
In operando measurement is less invasive than the in situ. For in operando measurement, the cell design has to be the same or very close to the cell design while it is running.
Let’s apply a zoological analogy: in situ characterizations concern the study of animals in a zoo, in operando characterizations concern the study of animals in their original (wild) environment.
One of the most challenging aspects of spectroelectrochemical characterizations is the synchronization of the two separated instruments. Most of the time, synchronization is managed by a trigger.
Another challenge is the customization of the cell in accordance with the necessary measurement. Most of the time, measurements are performed either in a bulk (Application Note #12) or onto thin film (Application Note #52).