Comparison of the growth process and electrochemical properties of polyaniline films prepared by pulse potentiostatic and potentiostatic method on titanium electrode

Polyaniline (PANI) films were deposited on titanium (Ti) electrode in a bath containing 0.3 mol L^-1 aniline and 1 mol L^-1 HNO ₃ by pulse potentiostatic method (PPM) and potentiostatic method (PM). The chronoamperograms during aniline polymerization were recorded, and the morphologies of PANI films prepared with different polymerization periods were examined under scanning electron microscope. The difference between the processes of PANI films growth was studied. The growth processes of PANI films prepared by PPM and PM are divided into two stages. For both PPM and PM, the first stage corresponds to the formation of a compact granular PANI layer on the surface of Ti electrode. The second stage corresponds to further growth of PANI film on the surface of the compact granular PANI film. However, the PANI films prepared by PPM and PM show different morphologies in this stage. In addition, the electrochemical properties of the PANI films prepared by PPM and PM are obviously different.