Enhanced electrochromic properties of a polypyrrole-indigo carmine-gold nanoparticles nanocomposite

An indigo carmine doped polypyrrole embedded with gold nanoparticles nanocomposite (PPy-IC-Aunanop) was synthesized by in situ electrochemical polymerization of polypyrrole in the presence of HAuCl4. The nanocomposite was characterized by in situ spectroelectrochemical experiments to study the effect of embedded gold nanoparticles on the electrochromic properties of the material. The results show the formation of a nanocomposite presenting enhanced electrochromic and optical properties, higher electroactivity and 10% lower band-gap energies. The PPy-IC-Aunanop presented a two-fold increase in optical contrast when compared to PPy-IC, in addition to better optical stability.