Electrosynthesis of polyaniline films on titanium by pulse potentiostatic method

Polyaniline (PANI) was synthesized on titanium electrode from aqueous solution containing 0.3 mol L−1 aniline and 1 mol L−1 HNO3 by pulse potentiostatic method. The chronoamperogram during polymerization process of aniline was recorded. The effects of the synthesis parameters, such as anodic pulse duration (ta), cathodic pulse duration (tc), lower limit potential (Ec) and upper limit potential (Ea), on the morphology and electroactivity of the PANI films were investigated by scanning electron microscopy (SEM) and cyclic voltammetry (CV). SEM results present that flake, mica-like, quasi-fibrous and nano-fibrous PANI film could be synthesized with various polymerization parameters. Under the following conditions, ta = 0.8 s, tc = 0.1 s, Ec = 0 V and Ea = 1.0 V, high quality nano-fibrous PANI film with the best electroactivity was obtained. The CV results show that the PANI films with different morphologies, which were prepared under the same anodic polymerization charge, have obvious different characteristics. This means that the PANI films with different morphologies have different electrochemical activity.