High-performance electrochromic device based on novel polyaniline nanofibers wrapped antimony-doped tin oxide/TiO2 nanorods

We report a novel electrochromic device (ECD) using polyaniline nanofibers wrapped antimony-doped tin oxide/TiO2 (ATO/TiO2@PANI) nanorods as electrochromic electrode material. The nanocomposites with core-shell structure were prepared by in situ chemical oxidative polymerization where aniline was polymerized in ATO/TiO2 nanorods aqueous dispersion. PEDOT:PSS film which was a complementary coloring material was used as counter electrode. A gel electrolyte (GE) was used in ECD. The architectural design of ECD based on ATO/TiO2@PANI film was ITO/ATO-TiO2@PANI/GE/PEDOT:PSSATO (ECD-TPN). Compared with the ECD based on pure PANI film (ECD-PANI), higher optical contrast (38.5% at 660 nm), higher coloration efficiency 202.2 cm(2)/C, faster response speed (t(c) = 1.2 s, t(b) = 1.0 s) and better cycling stability (sustaining 99.5% of its initial optical modulation after subjecting 5000 s) are archived by the ECD-TPN. The enhanced electrochromic properties are mainly attributed to the formation of the donor-acceptor system between the PANI nanofiber shell layer and the ATO/TiO2 nanorod, and the porous space among the ATO/TiO2@PANI nanocompsites and the PANI nanofibers, which can improve the efficiency of redox reaction, make the ion diffusion easier and provide larger surface area for charge-transfer reactions, respectively.