Electrical properties of conducting polypyrrole films functionalized with phthalocyanine

Abstract

Polypyrrole films containing phthalocyanine were deposited by direct electrochemical deposition method using mixed solvent system (NMP:H 2O) with H 2SO 4 (0.1 M). The films obtained were characterized by conventional techniques such as FT-IR and UV–VIS, which confirmed the incorporation of phthalocyanine. The presence of Cu(2p) core level peak in the ESCA studies also confirmed the incorporation of phthalocyanine in these films. The electrical conductivity was found to increase with the increase of phthalocyanine concentration in the electrolyte. Even for a moderate increase of CuPc (from 1.0 to 2.0 mol%) in the PPy films, there is a drop in activation energy from 0.133 to 0.08 eV. Sensitivity measurements show that the CuPc containing PPy films are selectively more sensitive to the nitrogen dioxide vapours. The C– V studies carried out on these films under illumination show that the photochemical response in electrochemical mode increases due to the presence of phthalocyanine. The cathodic peak at −700 mV, which is associated with the phthalocyanine, becomes prominent under illumination due to photogenerated carriers.