Electrochromic behaviour by lithiation process of nanocomposites based on WO3 nanofibers / electrochemically reduced TiO2

A new WO₃NF/TiO₂R electrochromic nanocomposite was synthesized on FTO substrate using a dip-coating technique combined with an electrochemical reduction treatment to induce defects in the reduced TiO₂ lattice (TiO₂R), followed by electrospinning deposition of WO₃ nanofibers (WO₃NF). The parameters used for electrospinning WO₃NF and the electrochemical reduction treatment applied to the TiO₂ layer affected the structural, optical, band gap and Urbach energy value, intrinsic defects, and electrochromic features of the resulting nanocomposite film. The electrochromic properties of the WO₃NF/TiO₂R nanocomposite in a Li⁺ electrolyte exhibited a colouration efficiency of 161.84 cm² C^–1, an optical modulation (ΔT) of 75.41 %, a reversibility of 61.31 %, and rapid response times of 3.5 s for colouration and 4 s for bleaching. The structure of the interconnected nanocomposite makes more places for redox reactions and speeds up charge transport. The WO₃NF/TiO₂R/FTO electrode had good capacitive behaviour, low charge resistance, and good durability for 1000 voltammetry cycles.

.The structure of the interconnected nanocomposite provides more sites for redox reactions and speeds up charge transport. The WO3NF/TiO2R/FTO electrode had good capacitive behaviour, low charge resistance, and good durability for 1000 voltammetry cycles.