Integration of VLS-Grown WO3 Nanowires into Sensing Devices for the Detection of H2S and O3

The inspiration behind this research is the development of tungsten oxide (WO3) nanowires based, highly sensitive and selective sensing devices directly on the active sensing platform. WO3 one-dimensional nanowires were synthesized via the vapour-phase growth technique. This approach allows the production of well-aligned and uniform nanowires on alumina substrates with their diameter and length in the nanometer range. The morphological and structural properties of nanowires have been investigated by means of the field effect electron microscopy, grazing incidence X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Finally, the fabricated WO3 nanowire sensing devices and their gas sensing performance were investigated in the presence of different oxidizing and reducing gases (especially environmental gases) at different temperatures. The WO3 sensors demonstrate high performance toward H2S and O3 at the optimal working temperatures of 400 and 200 °C, respectively, with the detection limit in the ppb level.