Nano-particles (NPs) of WO3-type compounds by polyol route with enhanced electrochromic properties

Marie Bourdin (1, 2) , Issam Mjejri (1) , Aline Rougier (1) , Christine Labrugère (3) , Thierry Cardinal (1) , Younès Messaddeq (2) , Manuel Gaudon (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 COPL - Centre d'Optique, Photonique et Laser
3 PLACAMAT - Plateforme Aquitaine de Caractérisation des Matériaux

Tungsten trioxide, synthetized as nanoparticles (NPs), then shaped as thin or thick films, has attracted considerable attention as a typical electrochromic material. Herein, the synthesis of WO3 nanoparticles by the polyol process followed or not by heat-treatments under air or argon, has allowed us to compare the electrochromic activity of powders with different morphologies and oxygen-deficiencies. Only the finest particles associated with pseudo-cubic structure due to a large oxygen-deficiency - on the contrary to the larger particles with standard monoclinic structure and W/O stoichiometric ratio - lead to films showing intense electrochromic color change from a whitish (bleached state) to a dark blue (colored state). Additionally, the as-prepared films exhibit quite fast electrochromic performance and satisfying cycling stability. The sub-stoichiometric nanoparticles prepared from polyol synthesis are of great potential for electrochromic applications.

Mots clés: Nanocrystalline; Electrochromism; Polyol Synthesis; Tungsten Oxide

Domaines: Matériaux

Marie Bourdin, Issam Mjejri, Aline Rougier, Christine Labrugère, Thierry Cardinal, et al.. Nano-particles (NPs) of WO3-type compounds by polyol route with enhanced electrochromic properties. Journal of Alloys and Compounds, 2020, 823, 153690 (10 p.). ⟨10.1016/j.jallcom.2020.153690⟩. ⟨hal-02490026⟩