Preparation and characterization of gasochromic Pt/WO3 hydrogen sensor by using the Taguchi design method

In the present work, nanostructured WO₃ films were prepared by the sol-gel spin coating method. The as-prepared films were annealed at different temperatures and their structures were characterized by field-emission scanning electron microscopy and X-ray diffraction. A layer of platinum (Pt) was then sputtered onto the surface of WO₃ films. The coloring/bleaching kinetics was evaluated by alternate exposures to H₂-N₂ mixture and air. The cycling change of coloration was obtained from the UV-vis spectra. The Pt/WO₃ thin films exhibited excellent gasochromic performance with good coloration change and fast response rate under ambient condition. Taguchi's experimental design approach was employed for conducting the experiments to study the influences of process parameters, such as annealing temperature, thicknesses of Pt catalyst and WO₃ films, on the gasochromic performance. The stability of the gasochromic Pt/WO₃ film was also evaluated by the switching cycle-life test.