Hydrothermally engineered WO3 nanoflowers: A selective detection towards toxic NO2 gas

Nanoflowers (NFs) of WO3 is decorated on glass substrate by inexpensive hydrothermal method at very low temperatures (80 and 100 °C). The structural investigations are studied through X- ray diffraction and surface morphological study of WO3 NFs were examined using transmission electron microscopy, field emission scanning electron microscopy, Brunauer- Emmett- Teller, and X- ray photoelectron spectroscopy technique. WO3 NFs exhibited hexagonal crystal structure. The porous structure of WO3 NFs possessing a specific surface area of 38.13 m2/g. WO3 NFs (W6 sample) shows remarkable gas sensing towards toxic NO2 gas (225% response for 100 ppm at operating temperature 200 °C). WO3 NFs exhibits excellent reproducibility and stability (80%). An interaction mechanism of gas and WO3 NFs studied using an impedance spectroscopy.