Fast electrochromic response of ultraporous polyaniline nanofibers

Polyaniline (PAni) nanofibers were prepared by a one-step electrosynthetic method. A gold sputtered electrode was used as the substrate for the nanofiber growth at a constant current density value of 100 μA cm−2. Substrate morphology induces fiber growing and allows having a remarkable quantity of fibers in a short period of time. Tandem chronoabsorptometric and chronocoulometric data of the electro-synthesis process were collected and analyzed. Several electrochromic parameters were characterized and a short response time (T90) of 20 ms was obtained for a contrast (ΔT %) of 10%. The main reason for this fast response is the ultraporous nature of the prepared nanofibers. This approach represents a straightforward, easy and low cost method to obtain a fast color switching film with potential application in the deployment of an electrochromic device.