Low temperature acetone sensor based on Sol-gel grown nano TiO2 thin film

Thin film Sol-gel grown nano TiO₂ based resistive sensor was developed to detect acetone at low temperature. Structural characterization were carried out using XRD, FESEM and AFM to ensure the crystalline, grain size and surface roughness of the TiO₂ thin film and anatase phase TiO₂ having particle size in order of 10 to 20 nm with average roughness 100nm. The thin film with catalytic Pd contact were investigated for acetone vapor sensing in the range of 150-250°C for acetone concentration 500-1500 ppm with N₂ as carrier gas. The maximum response 178 % approximately was obtained at the optimum temperature of 150^oC for 500 ppm acetone. The dynamic range of the sensor was also found to be quite appreciable (500-1500 ppm). The response and recovery time 42s and 44s respectively was recorded at 500 ppm at optimum temperature. The short term stability study indicated that the sensor is appreciably stable with a nominal baseline drift of ±6 %.