Effect of pH of electrolyte on electrochemical polymerization of o-anisidine: Cyclic voltammetry study

The effect of pH of electrolyte on electrochemical polymerization (ECP) of o-anisidine has been investigated. The poly(o-anisdine) thin films have been prepared by ECP of o-anisidine on SnO2:F coated glass substrates under cyclic voltammetric conditions. Cyclic voltammetry investigations indicate the loss of electroactivity of the films of pH values above 2.22. The optical absorption spectroscopy study reveals the predominant formation of insulating pernigraniline base (PB) at higher pH values while at lower pH values exclusive formation of the emeraldine salt (ES) phase is observed. A clear transition from insulator to conductor has been observed between the pH 1similar to2. The morphology of the films is found to strongly depend on the pH of the electrolyte.