Synthesis and Electrochromic Properties of Hybrid Films Comprising WO₃ Nanowires Coated with V₂O₅ Nanoparticles

The WO₃/V₂O₅ nano films were synthesized in two steps: first, the WO₃ nanowires were deposited on substrate of fluorine-doped tin oxide (FTO) glass by solvothermal reaction; second, amorphous V₂O₅ nanoparticles were uniformly coated on the WO₃ nanowire surfaces by electrochemical deposition. The impact of the nano-structured WO₃/V₂O₅ coatings on the optical and electrochromic properties was investigated with X-ray diffraction, scanning electron microscopy, ultraviolet visible spectroscopy and cyclic voltammetry. The results showed that the coatings, comprising the “core-shell”shaped WO₃/V₂O₅ nano-structured grains, displayexcellentelectrochromic properties, outperforming the V₂O₅ films because of better cycle stability, greater transmittance modulation (67% at 776 nm) and higher coloring efficiency (13. 5 cm²·C^-1 at 776 nm). We suggest that the newly-developed nano-structured WO₃/V₂O₅ coatings may be of much technological interest as the stealth or intelligent discoloration material.