Enhanced Electrochromic Performance of Mesoporous Titanium Dioxide/Reduced Graphene Oxide Nanocomposite Film Prepared by Electrophoresis Deposition

A novel and scalable method combining surfactant template and electrophoresis deposition was used to prepare mesoporous titanium dioxide/reduced graphene oxide (TiO2/RGO) nanocomposite film with the assistance of sodium dodecyl benzene sulfonate using tetrabutyl titanate and graphene oxide (GO) as raw material. The electrochromic mechanism of TiO2/RGO nanocomposite film was investigated by XPS technique. The TiO2/RGO nanocomposite film showed that TiO2 nanocrystals can be anchored on the surface of RGO via chemical bonding such as Ti-O-C and Ti-C. The TiO2/RGO nanocomposite film exhibited shorter coloration/bleaching response times (3.9 s for coloration and 6.6 s for bleaching), higher coloration efficiency (34.9 cm(2) C-1) and better coloration/bleaching cycle stability compared with pure TiO2 film. The electrochromic mechanism of TiO2/RGO nanocomposite film was accorded with valence transition model, and an island-bridge model was proposed to interpret the enhancement mechanism of electrochromic performance. This enhancement is mainly due to a larger specific surface area, higher electrical conductivity and better structural stability in TiO2/RGO nanocompositc film, which facilitates faster transport of Li+ ions and electrons, and longer coloration/bleaching cycle life. This work provides an effective approach and inspiration to improve the electrochromic performance of transition metal oxides, as well as explore other high-performance electrochromic materials. (C) 2018 The Electrochemical Society.