In situ synchrotron far-infrared spectromicroscopy of a copper electrode at grazing incidence angle.
Synchrotron far-infrared spectroscopy in situ was successfully carried out on a copper microelectrode using a grazing-angle objective attached to a Bruker IRscope II microscope. The thin-layer spectroelectrochemical cell was constructed out of Teflon and fitted with a 20 microm-thick Mylar window; the copper electrode was 500 microm in diameter. Measurements were carried out in 0.1 M NaOH solution as a function of applied potential between -1.4 and 0 V versus a Hg/Hg2SO(4) reference electrode. Results demonstrate that with the present technique it is possible to obtain in situ spectra with excellent signal-to-noise ratio for surface oxide films formed electrochemically with less than 1 nL of active solution volume. The surface film on copper at 0 V consisted mainly of CuO with possibly some Cu(OH)2 also present. This interpretation is consistent with previous works and thermodynamic calculations.
Hahn
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F
UMR 6503, CNRS, Université de Poitiers, 40 avenue du Recteur Pineau, F-86022 Poitiers, France.
Mathis
Y -L
Y-
Bonnefont
A
A
Maillard
F
F
Melendres
C A
CA