Preparation of various metal ions doped hydrogen titanate nano particle coated thin films by layer-by-layer self-assembling method for an electrochromic electrode

Three kinds of metal ions (Fe, W, and Li) doped hydrogen titanates were hydrothermally prepared at 130 °C for 48 h in a strong basic solution, and then were directly coated on fluorine-doped tin oxide glass substrate using layer-by-layer self assembling method, by means of dispersing them in distilled water, for an electrochromic electrode material. Prepared powders were fully characterized using SEM, XRD, cycle voltammetry and colorimeter. All the prepared titanate nano particles were confirmed consisting of layered structures by XRD analysis. Particle shape of Li-doped titanate powder alone had nano-sheet shape, whereas other metal ion doped titanate powders had nanotubular shape. Electrode coated using Fe-doped hydrogen titanate with nanotubular shape showed the best reversible reaction resulting in faster response time and deeper color than other titanate coated films due to enhanced electrical conductivity by doping and to large interface area between electrode and electrolyte.