Synthesis of WO3 nanoflakes by hydrothermal route and its gas sensing application

The controlled morphology and size of inorganic materials have attracted intense interest, as these parameters play an important role in determining sensing properties. Herein, WO3 thin film is hydrothermally grown on FTO substrate at 175 degrees with the assistance of seed layer deposited by spray pyrolysis technique. The WO3 thin film was characterized by X-ray Diffraction (XRD), micro-Raman spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and UV-vis Spectroscopy for determination of physico-chemical properties. Moreover, X-ray Photoelectron Spectroscopy (XPS) analysis is carried out to understand chemical states and boding. Systematic gas sensing studies were performed for NH3, H2S and CO gases under static condition. The sensing study reveals, WO3 nanoflake exhibits a superior sensor response to NH3 gas. Moreover, it exhibits higher sensitivity to NH3. Gas sensing properties indicate WO3 nanoflakes holds promise to become a potential candidate for NH3 gas detection at the expense of lower power consumption. (C) 2020 Elsevier B.V. All rights reserved.