Deactivation of Poly(o-Aminophenol) After its Interaction with Ferric Cations: Effects on the Protonation Reaction and Electron Transport

The aim of this work was to demonstrate that interaction of ferric cations with poly(o-aminophenol) (POAP) films causes their deactivation. Spectroelectrochemical measurements and rotating disk electrode voltammetry (RDEV) were employed on both freshly prepared and deactivated POAP films. It was observed a reduction (deactivation) of the redox activity of POAP after its treatment with ferric cations. A degree of deactivation of POAP was defined on the basis of the reduction of the voltammetric charge after its interaction with a ferric cation solution. With regard to spectroelectrochemical measurements, absorbance as a function of both wavelength and electrode potential, seem to demonstrate that redox sites of a deactivated POAP film are less protonated than redox sites of a freshly prepared film. RDEV measurements indicate the existence of a slower electron transport in a POAP film treated with a ferric cation soluion, as compared with the electron transport in a non-deactivated film.