Synthesis, characterization and gas sensing performance of tungesten oxide by hydrothermal method

Abstract

Abstract In the current work, tungsten trioxide (WO3) thin film is primed by a wet chemical-assisted hydrothermal processing at 180 °C for 7 h with sodium tungstate and hydrochloric acid on a soda-lime glass substrate without assistance of any seed layer. The WO3 thin film sample was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and UV–Vis spectroscopy. The X-ray diffraction study discloses the prominent orientation along (0 0 1), (0 2 0) and (2 0 0) planes which reveals the preferential growth direction of monoclinic WO3. Morphological studies indicated the flake-like shapes of WO3. Gas sensing tests exposed that the WO3 has remarkable enhanced performance. It detected nitrogen dioxide (NO2) gas in a wide concentration range with very high response, fast response–recovery time, good selectivity and stable repeatability. The results indicates that WO3 could be a promising material for high performance gas sensor devices.