文摘
High-performance electrochromic films based on tungsten oxide hydrate ([WO2(O2)H2O]·1.66H2O) colloidal nanocrystals with fast switching speed were fabricated by laser ablation in a mixture of water and hydrogen peroxide followed by electrophoretic methods. Through electrophoretic deposition, the nanoparticles in the colloids synthesized by laser ablation aggregated onto the FTO coated glass substrate forming a lager cell with a uniform size of around 200 nm, which subsequently self-assembled into a porous tungsten oxide hydrate film. By optimizing the electrophoretic time (800 s) and voltage (−0.5 V), the mesh-like porous tungsten oxide hydrate film achieved a wide optical modulation of 32% at 632 nm, fast coloration and bleaching response speed of 7.8 s and 1.7 s respectively due to the synergetic effect of the unique atomic structure of [WO2(O2)H2O]·1.66H2O and porous structure with large surface area that facilitates the ion insertion/extraction. Thus the tungsten oxide hydrate can be a promising electrochromic material for practical applications.