Formaldehyde‐, Benzene‐, and Xylene‐Sensing Characterizations of Zn–W–O Nanocomposite Ceramics

Zn–W–O nanocomposite ceramics with the whole concentration range ( W at.%=0%, 1%, 5%, 25%, 50%, 75%, 95%, 99%, and 100%) have been fabricated by the sol–gel method, starting from zinc acetate dihydrate, ammonium tungstate, monoethanolamine (MEA), and anhydrous ethanol. Nanocomposites, that were sintered at 650°C in a conventional oven for 120 min were ultrasonically emulsified and coated on alumina ceramic tubes by dip coating. The microstructure and morphology of nanocomposites were characterized by X‐ray diffraction (XRD) and field emission scanning electron microscope (FESEM), respectively. The resistance and sensitivities to poisonous volatile organic compounds (PVOCS) were investigated on the static testing chamber. The XRD analysis of nanocomposites revealed the appearance of ZnWO 4 with a monoclinic structure in the whole concentration range (1–99 at.%). The FESEM results showed that as‐prepared nanocomposites were composed of almost spherical particles with size range from 200 to 300 nm. Gas‐sensing properties of Zn–W–O nanocomposites ceramics, to formaldehyde, benzene, and xylene, were detected. The results showed that the ZnWO 4 phase with high resistance almost did not respond to PVOCS. The appropriate amounts of ZnWO 4 in ZnO‐rich samples and in WO 3 ‐rich samples lend themselves to enhancement of gas‐sensing properties to PVOCS. The effect of ZnO, WO 3 , and ZnWO 4 with a scheelite structure as solid acidic/alkaline catalysts on gas‐sensing property is also discussed.