Solution precursor plasma-sprayed tungsten oxide coatings for nitrogen dioxide detection

Solution precursor plasma-sprayed (SPPS) tungsten oxide (WO3) coatings used as nitrogen dioxide (NO2) gas sensitive layers were investigated. X-ray diffraction (XRD) analysis, combined with field-emission scanning electron microscopy (FE-SEM) confirm the deposition of nanostructured porous and continuous WO3 coatings directly from WCl6 ethanol solution. The as-sprayed coatings, without any post heat-treatment, show well-crystallized monoclinic phase structure. The sensors using SPPS WO3 coatings as sensitive layers exhibit good response to NO2 in sub-ppm range.