Abstract
Iodine adsorption on a polycrystalline gold electrode was studied by in situ electrochemical Rutherford backscattering (ECRBS) using an ultrahigh vacuum (UHV)-electrochemical cell comprising of a thin-film silicon nitride window. The depth resolution of RBS allowed for measurement of nuclide concentration of the diffuse double-layer, electrode surface and near-surface regions. ECRBS measurements on the gold electrode, initially exposed to -500 mV vs. a platinum pseudo-reference electrode, in a potassium iodide solution, showed an increase in the 2.07 MeV iodine peak indicative of iodine adsorption. The surface concentration of the iodine adlayer was directly measured by ECRBS to be 1.3 ± 0.3 nmol/cm2. ECRBS measurements on a gold electrode exposed to 1.5 V vs. a platinum pseudo-reference electrode, in a potassium iodide solution display a decrease in the 2.16 MeV gold peak and a shift to lower energies. Scanning electron microscopy images of electrodes studied by ECRBS displayed roughened surfaces consistent with gold dissolution. This work demonstrates the potential for in situ ECRBS using thin-film silicon nitride windows to become a powerful tool for the investigation of a wide range of electrochemical processes in areas such as corrosion, electrodeposition and electrocatalysis.
Original language | English (US) |
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Pages (from-to) | 1777-1783 |
Number of pages | 7 |
Journal | Electrochimica Acta |
Volume | 54 |
Issue number | 6 |
DOIs | |
State | Published - Feb 15 2009 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Chemical Engineering
- Electrochemistry
Keywords
- Etching
- Gold
- In situ RBS
- Iodine adsorption
- Ion scattering
- Polycrystalline gold electrode