Study of the electrochemical stability of polypyrrole coating on iron in sodium salicylate aqueous solution

- Electrochemical stability of PPy/Fe in aqueous sodium salicylate is studied.
- Such PPy cannot be used at potential higher than +(0.3-0.4) V.
- The PPy potential window can be widened by lowering the salicylate concentration.
- Even though, the electroactivity and the electrical properties of PPy are retained.

In this work electrochemical stability of optimized PPy film on iron in aqueous solution of sodium salicylate is studied. The main drawback of conducting polymers is their possibility to undergo an irreversible degradation (overoxidation). The overoxidized polymers lose their properties, for example, conductivity and redox activity, what excludes them from some practical applications. This study demonstrates that lowering the concentration of salicylate in the electrolyte increases the electrode potential, at which overoxidation of PPy begins. It widens the electrode potentials, within which such a polymer can be used. Moreover, it is evidenced that even though the electrolyte concentration is lowered, the redox activity and the electrical properties of the PPy film are retained.