XP‐Spectra, Sputterexperiments and UV‐VIS‐Reflection Spectra of Polyaniline

Abstract

Abstract Electrochemically formed polyaniline (PANI) films were studied both in situ and ex situ using XPS and UV/VIS spectroscopy. The samples studied ex situ were removed at given potentials and rinsed with water, with no changes in the oxidation state or concentration of counter ions. PANI‐RED (0.0 V (SHE)) contained no anions and the XP‐spectra showed an emeraldine‐like structure and 0.27 protonated nitrogen atoms/monomer. PANI‐OX (1.0 V (SHE)) contained 0.2 — 0.3 counter ions/monomer throughout the film. UV/VIS spectroscopy shows a two step redox mechanism involving radical cations. The extended conjugation of PANI‐OX was followed by both reflection spectroscopy and XP‐shake‐up peaks accompanying the photoionisation process. At potentials above 1.0 V (SHE) overoxidation occurs with the removal of anions from the bulk fil