Probe Beam Deflection for the Analysis of Ion Fluxes at the Solid/Liquid Interface

The probe beam deflection (PBD) technique is based on the deflection of a laser beam, aligned parallel to the electrode surface, caused by the concentration profile evolving in front of the electrode during an electrochemical reaction. Monolayer and sub‐monolayer sensitivity has been achieved by means of PBD for (i) the proton flux during oxide formation/reduction on a polycrystalline gold electrode and (ii) for the under potential deposition (UPD) of copper on platinum. The potential of the PBD technique for the analysis of electrochemical reactions is demonstrated for the intrinsic redox reaction occurring on activated glassy carbon (GC) electrodes as a consequence of the generation of surface functional groups. PBD clearly reveals that protons are exchanged in acidic electrolyte on activated GC. Finally, the O2 reduction on Au in alkaline electrolytes has been monitored by the probe beam deflection technique.