Mixed nanostructured Ti-W oxides films for efficient electrochromic windows

Abstract

With the aim to enhance the electrochromic (EC) efficiency and electrochemical stability of electrochromic devices (ECD), mixed nanostructured TiO 2/WO 3 films were prepared by an electrochemical deposition method with the purpose of adding WO3 nanoparticles to porous nanocrystalline doctor-blade TiO 2 (nc-TiO 2) films. The results of the characterization of electrochromic properties in 1M LiClO4 + propylene carbonate (LiClO 4 + PC) of both the nc-TiO 2/F-doped tin oxide (FTO) and WO3/TiO 2/FTO configurations showed the reversible coloration and bleaching of the ECDs. The response time of the ECD coloration of WO3/TiO 2/FTO was found to be as small as 2sec, and its coloration efficiency (CE) as high as 35.7cm 2 × C -1. By inserting WO3 nanoparticles into the porous TiO 2 structures, WO3/TiO 2 heterojunctions were formed in the films, consequently enabling both the CE and electrochemical stability of the working electrodes to be considerably enhanced. Since a large-area WO3/TiO 2 can be prepared by the doctor-blade technique followed by the electrochemical deposition process, mixed nanostructured Ti-W oxides electrodes constitute a good candidate for smart window applications, taking advantage of the excellent coloration and stability properties as well as the simple and economical fabrication process involved. Copyright © 2012 Nguyen Nang Dinh et al.