A study of the physical properties and gas‐sensing performance of TiO₂ nanofilms: Automated nebulizer spray pyrolysis method (ANSP)

Automated nebulizer‐sprayed TiO₂ nanofilms were deposited on the glass substrate by using different temperature (300, 350, 400, 450, and 500 °C). The effect of temperature on the structural study by XRD and AFM reveals that the amorphous nature turns to stabilized anatase tetragonal phase with an enhancement of the preferred orientation (101), particle size, average roughness of the topographical view and thickness (238, 279, 304, 362, and 397 nm) of the coated films. The morphological study by the FESEM method shows a crack and a void free micro grain particle due to the effect of temperature. An optical study shows that the transmittances of all the samples gradually decreased and the redshift of the absorption edges with decreased bandgap (3.67–3.35 eV) value is observed by the influence of temperature. The n‐type semiconducting nature of TiO₂ nanofilms shows the voltage drop across the sensor element on exposure to the reducing gas. Among the various gases (CH₄O, C₃H₈O, NH₃, C₃H₆O) the reducing gas C₂H₆O exhibits a better response for a 500 °C coating temperature at an optimal operating temperature of 300 °C with 150 ppm gas concentration.