posted on 2024-02-10, 14:03authored byAlice Fiocco, Aja A. Pavlic, Frédéric Kanoufi, Emmanuel Maisonhaute, Jean-Marc Noël, Ivan T. Lucas
Tip-enhanced
Raman spectroscopy (TERS) is an emerging
nanospectroscopy
technique whose implementation in situ/operando,
namely, in the liquid phase and under electrochemical polarization
(EC-TERS), remains challenging. The investigation of electrochemical
processes at the nanoscale, in real time and over wide potential windows
can be of particular interest but tedious when using EC-STM-TERS.
This approach was successfully applied to the investigation of a well-established
but yet complex system (a thiolated nitrobenzene derivative 4-NBM)
whose reduction mechanism involves various multistep reaction paths,
most likely pH-dependent. In light of the EC-TERS analysis carried
out under specific conditions limiting the full (6 e–/6 H+) electrochemical reduction of 4-NBM and its photocoupling,
a bimolecular electrochemical reaction path, difficult to evidence
from the electrochemical response only, is proposed.