Characterization and enhancement in conductivity and conductivity stability of electropolymerized polypyrrole/Al₂O₃ nanocomposites

In this study, a nanocomposite of 80 nm α-Al₂O₃-incorporated polypyrrole (PPy) film was electropolymerized on a Au substrate. It was found that the nucleation and growth were instantaneous three-dimensional processes before and after nuclei overlapping for pure PPy electropolymerization. However, a distinguishable nucleation and growth mechanism before nuclei overlapping was shown for the preparation of the nanocomposite. The nanocomposite demonstrates an extremely high oxidation level revealed from the analyses of X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman scattering (SERS). Also the conductivity of the nanocomposite was increased substantially (∼5.4 times) and it can depress aging in a 50% relative humidity, 20% (v/v) O₂ and 30°C atmosphere for 60 days, in comparison to pure PPy.