Electrochromic property of the viologen-anchored mesoporous TiO2 films

The electrochromic properties of the viologen-anchored mesoporous TiO2 (Meso-TiO2) films were investigated in this work. The Meso-TiO2 films, synthesized by evaporation-induced self-assembly (EISA) process, deposited on ITO electrodes were a worm-like structure with an average pore diameter of 7.0 nm. The electrochromic devices (ECDs) fabricated from the Meso-TiO2 demonstrated 3 times of coloration efficiency and considerably faster switching response, compared with those from the nanocrystalline films made of the 7 nm-sized TiO2 nanoparticles. The advantage of the Meso-TiO2 would originate from the well-organized mesopore structures, offering an efficient electrolyte transport as well as the fast electron transfer from the ITO electrode to the anchored viologen.