Oxidative polymerization of pyrrole photocatalyzed by TiO₂ nanoparticles and interactions in the composites

Abstract

Abstract Oxidative polymerization of pyrrole is initiated by photoexcited TiO 2 nanoparticles. Pyrrole oligomers and polypyrrole (PPy) are continuously produced with reaction time. The conversion of pyrrole monomer changes as a function of the concentration of TiO 2 nanoparticles. It is found that PPy in the composite has the conjugated structure and is partially oxidized with a formation of positively charged N + . Results from X‐ray photoelectron spectroscopy and Raman analysis consistently indicate that a strong interaction is established between the TiO 2 and PPy. According to the results of UV–vis spectroscopy, a mechanism of photocatalytic oxidation is proposed for this polymerization. The interaction between TiO 2 and PPy is found to arise from the photocatalytic reaction and discussed in terms of photoinduced Ti 3+ . © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008