Interface effect on the electropolymerized polypyrrole films with hollow micro/nanohorn arrays

Polypyrrole (PPy) films with hollow micro/nanohorn arrays were controllably synthesized in p-toluenesulfonate aqueous solutions by template-free electrochemical methods. The micelles which consist of pyrrole monomers and the surfactants provided the soft templates during the polymerization process. The polymerization potential and pH value of the solutions cooperatively influenced the shape of the micelles at the substrate/electrolyte interface and further controlled the morphologies of PPy films. PPy grew along the soft templates during the high potential periods of a pulse potentiostatic (PPS) method, while the pH value and the low potential were varied to modulate the shape of the soft templates. It has been shown to be most appropriate to fabricate hollow micro/nanohorn PPy films with the highest electrical conductivity (190 S cm(-1)) via PPS at pH ∼1.5. A diagram was also introduced in order to illustrate the polymerization potential and pH value dependence of nanohorn PPy morphologies. This work proposed a potential method to the in situ growth of conducting polymers with high conductivity and high specific surface area.