A facile electrochemical strategy for synthesis of 3D nanodimensional polypyrrole structures using self-assembled layers of pyrrole monomers

•An electrochemical route for direct synthesis of nanodimensional polypyrrole films on solid electrodes was used.•The applied methodology is a template-free simple electrochemical process.•Pyrrole monomers were adsorbed on metal surface through a self-assembly process.•Applying a constant current to the samples, in the absence of monomer, led to blackish polypyrrole layer.•The nanodimensional polypyrrole structures were formed under some circumstances.

The formation of nanodimensional conductive polymers is one of the major challenges of scientists. They show enhanced performance compared to the bulk structures, because of their higher surface area to volume ratio. However, most of synthesis strategies are chemical, template-assisted techniques with difficult controlling factors. The electrochemical routes have been considered in recent years, since they are more simple and controllable than chemical methods. The present work, reports a simple electrochemical method for synthesis of 3D nanostructured polypyrrole films. The idea was that pretreatment of electrode with pyrrole monomers may lead to their adsorption on metal surface. Then, a very thin polymer film is formed by applying a constant current in a monomer-free solution to the pretreated electrodes; the morphology of this film was expected to be different from the morphology of commonly electrosynthesized bulk polymer films. Scanning electron microscopic studies showed that the nanodimensional slates of polypyrrole have been formed during this procedure. Atomic force microscopy images verified the formation of nanostructured polymer film. The effect of monomer concentration, immersion time and substrate properties on the morphology of the nanostructures was evaluated. Cyclic voltammetry tests were performed and the results showed significant enhancement in surface area of the polypyrrole films.