INCORPORATION AND EXPULSION OF ELECTROLYTE SPECIES BY TUNGSTEN-TRIOXIDE-CONFINED, WO3-VERTICAL-BAR-POLYANILINE, AND CAL-BAR-PAN-VERTICAL-BAR-POLYVINYLSULFATE-CONFINED ELECTRODES DURING POTENTIAL CYCLING
K. Ogura et al., INCORPORATION AND EXPULSION OF ELECTROLYTE SPECIES BY TUNGSTEN-TRIOXIDE-CONFINED, WO3-VERTICAL-BAR-POLYANILINE, AND CAL-BAR-PAN-VERTICAL-BAR-POLYVINYLSULFATE-CONFINED ELECTRODES DURING POTENTIAL CYCLING, Journal of electroanalytical chemistry [1992], 451(1-2), 1998, pp. 219-227
The ion-transport properties of the tungsten trioxide (WO3)-, WO3/poly
aniline (PAn)-, and WO3/PAn polyvinylsulfate (PVS)-confined electrodes
have been studied by means of the in situ Fourier transform infrared
(FTIR) spectroscopic method. In highly acidic solution (pH = 0), (WO3)
-O-VI, was reduced to (HxWO3)-O-V by the reaction with H3O+ and the ge
nerated H2O molecules were incorporated in the film, but in solutions
of pH greater-than-or-equal-to 2, the reduction of (WO3)-O-VI, was att
ained by the reaction with H2O and the concentration of H2O decreased
in the film. The charge-compensating reaction for the reduction of WO3
/PAn films in solutions of pH greater-than-or-equal-to 2 depended on t
he electrode potential. In the potential range between + 0.2 and - 0.2
V versus Ag/AgCl, the reduction of the positively charged PAn was ach
ieved by expelling anions without the accompanying injection of cation
s into WO3. In the potential range between - 0.3 and - 0.8 V, however,
WO3 and the charged PAn were simultaneously reduced by protons. PVS r
emained doped at the WO3/PAn/PVS-confined electrode during potential c
ycling, and the charge-compensation was accomplished by involving cati
ons. (C) 1998 Elsevier Science S.A. All rights reserved.