Electrochromic Properties of PANI/TiO2 Nanocomposite Films Prepared by Electropolymerization

PANI/nc-TiO2/ITO composite films were prepared by electrochemical method where the monomer aniline was polymerized onto nano-porous TiO2/ITO films (PANI/nc-TiO2/ITO). The PANI/nc-TiO2 heterojunctions were formed in the composite films due to the insertion of PANI in nano-porous TiO2 particles. PANI/ITO films exhibited a reversible electrochromic display (ECD) performance when cycled in 0.1M LiClO4 + propylene carbonate. The response times of the electrochromic coloration and bleaching of the PANI/nc-TiO2/ITO electrode were 15 s and 20 s, respectively. Electrochromic efficiency of the films reached a value as large as 12.25 cm2´C-1. Taking advantage of the large EC efficiency and electrochemical stability as well as the simplicity of the fabrication process, PANI/nc-TiO2 composite films can be used for preparation of electrochromic smart windows, in term of the large-area production in particular.