Structure Design and Performance Research of WO3 Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Abstract The time‐consuming and laborious heat treatment is indispensable for preparing seed layer in solvothermal synthesis of WO 3 film. Herein, WO 3 film is prepared composed of single crystal WO 3 nanowires on indium tin oxide (ITO) glass assisted with simple and energy‐saving electrodeposited seed layer for the first time. The catalyst Pt is sputtered on it for 30 s after WO 3 film is synthesized to form the hydrogen gasochromic film. The film structure is redesigned to improve its hydrogen gasochromic properties further. Before WO 3 film is solvothermally synthesized, Pt is sputtered on seed layer for 15 s, then it is sputtered for 15 s again after WO 3 film is prepared. The Pt sputtered on seed layer greatly changes the morphology of nanowires, making them sparse, slender, and cross‐linked like a bird's nest. Moderate 37% HCl is added during the solvothermal process to promote the growth of WO 3 nanowires. The variation of transmittance (wavelength: 1000 nm), coloring rate (4% H 2 /Ar) and bleaching rate (air) of WO 3 hydrogen gasochromic film with new structure at room temperature are 69.1%, 3.1%/s (increases 19.6%) and 0.85%/s (increases 193%), respectively. This study offers a new strategy for seed layer technology of WO 3 film and structural design of WO 3 hydrogen gasochromic film.