Electrochemical synthesis of microporous polyaniline films using foam templates prepared by ultrasonication

•Ultrasonication was used to foam the electrolyte solution containing a surfactant.•The foamy electrolyte template was prepared by ultrasonication.•The PANI film was synthesized in the foamy electrolyte template.•The PANI film possessed porous structures composed of a number of micropores.•The porous PANI film exhibited a faster charging and discharging current responses. We report a new soft template method for the synthesis of unique polyaniline (PANI) films with microporous structures. In this process, ultrasonication is used to foam an electrolyte solution containing a surfactant, which is subsequently employed as a soft template for PANI growth via the electrochemical polymerization of aniline. Analysis by scanning electron microscopy demonstrates that the resulting PANI films contain numerous micropores. These microporous PANI films exhibit faster charging (doping) and discharging (dedoping) current responses compared to ordinary flat films of the same material.