SURFACE-PROPERTIES OF PBO2 AND BI-MODIFIED PBO2 ELECTRODES

We have studied the surface composition and vibrational properties of PbO2 and Bi-doped PbO2 electrode surfaces using Auger electron spectroscopy (AES) and high resolution electron energy loss spectroscopy (EELS). Deposition from perchlorate solution yields chlorine-rich oxides. For PbO2, chlorine tends to segregate at the surface. For Bi-PbO2, chlorine does not segregate at the surface, but the concentration of chlorine throughout the bulk of the oxide is about three times that in PbO2. This suggests that Bi and Cl may be chemically bound in the doped oxides. Hydroxyl groups and hydrocarbon fragments are also present throughout the bulk of both films. Both oxides exhibit distinct phonon loss spectra, similar to those observed by other authors with EELS for many other oxides. Subtle differences between vibrational frequencies of the two oxides may be related to differences in surface crystallographic orientation or to differences in chemical composition. © 1990, The Electrochemical Society, Inc. All rights reserved.