An ultra-fast response gasochromic device for hydrogen gas detection

In the present work, gasochromic tungsten oxide (WO3) thin films on glass substrate were fabricated by Pulsed Laser Deposition (PLD) system. Pt was sputtered on the surface of WO3 thin films as a catalyst layer for hydrogen gas detection. The gasochromic properties of Pt/WO3 thin films at room temperature were determined by examining their optical transmittance under various H2–N2 mixture gas exposures. The results show that in low H2 atmosphere (0.5%) the room temperature grown Pt/WO3 thin films still exhibited noticeable transmittance change, within the visible light (550–700 nm) range. WO3 thin films have been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). XRD and TEM confirmed that the morphology of the best performance WO3 thin film is amorphous, and SEM investigations revealed that the thin films were composed of nanotextured grains.