Electrophoretic deposition of Au@PEDOT nanoparticles towards the construction of high-performance electrochromic electrodes

High performance electrochromic electrodes prepared by the electrophoretic deposition of Au@PEDOT (gold@poly (3,4-ethylenedioxythiophene)) nanoparticles were characterized. A detailed study was performed using scanning transmission electron microscopy (STEM) combined with a chemical analysis at the nanometer level showing core–shell structures with sizes ranging from 2 to 8 nm. X-ray diffraction and Raman experiments were also performed. The modified electrodes present homogeneous surfaces with increased roughness, leading to excellent electrochromic properties like a high chromatic contrast with an electrochromic efficiency of ca. 300 C−1 cm2 with a response time of approximately 60–70 ms for 90% of coloration. The fast switching was related to the location of the solid state electrochromic reaction, the very thin PEDOT layer surrounding the Au core of the nanoparticles.