Pnai Films Fabricated by Pre‐Nucleation Electrodeposition Method with High Electrochemical Activity: Parameter Optimization and Analysis

Abstract Electrochromic polyaniline (PANI) films with high electrochemical performance have been intensively pursued for their potential applications in various fields. Here, the growth process of the PANI films synthesized by the pre‐nucleation electrodeposition method is analyzed and the optimal parameters with highest electrochemical activity are obtained. The PANI film fabricated under high current density of 10 mA cm −2 and impact time of 0.2 s shows the best electrochemical performance. It has a maximum active charge of 22.3 mC cm −2 . The optimum electrochemical performance is attributed to the loose and porous structure. The PANI films fabricated under the optimal parameters also show the flattest structure and the smooth surface. It concludes a universal evaluation basis of the optimal conditions for the pre‐nucleation method. That is, in the nucleation stage, the potential curve shall peak rapidly and then fall slowly to the valley without any upward growth; when entering into the low current density growth stage, the potential shall fall rapidly to a certain value and grow at that potential smoothly. This work evokes a deeper understanding and controlling of the growth process of polymers.