Contact : Fouad Maroun
Participants : Fouad Maroun, François Ozanam, Alistair Rowe
Collaboration : EPS team, PMC laboratory
Financial support : ANR ECvibraPlas
One of the new research topics of the ECM team is to study the influence of a plasmonic infrared vibrational excitation on electrochemical reactions. Recently, it was demonstrated that a chemical reaction is modified when performed in an optical cavity tuned to one of the vibration energies of the molecules along the reaction path. In ECM team, we aim to apply these concepts to electrochemical reactions and to study how electrochemical reactions are modified in the presence of vibrational excitations. For this purpose, we propose to design plasmonic electrodes absorbing in the infrared range to enhance the infrared electromagnetic field at the electrode surface and induce large vibrational coupling of the molecules with the plasmon mode. We propose to use ultrathin Au films either formed from densely packed monolayers of Au nanoparticles or an array of Au antennas. The films will be grown electrochemically or by evaporation in vacuum using microfabrication techniques, both grown on a Si prism or hemisphere. The electrochemical cell design allows for normal electrochemical operation under backside illumination of the electrode by a tunable infrared laser. The Au ultrathin films will be electrochemically covered by an ultrathin layer of catalyst (e.g. Ir, Pt, Cu) which will be chosen as a function of the studied electrochemical reaction (Ir for oxygen evolution reaction, Pt and Cu for CO₂ reduction). These two electrochemical reactions are important for energy and CO₂ conversion.
Scheme representing the infrared excitation configuration of gold nanoparticles and gold micro-antennas deposited on Si under electrochemical conditions.