Selectivity of an Ag/BTO-Based Nanocomposite as a Gas Sensor Between NO and SO Gases.

The novel Ag/BTO/TiO nanocomposite was assessed for its gas-sensing capabilities toward hazardous gases NO and SO. It exhibited p-type behavior with increasing resistance for SO with a response and recovery time of ∼5 and ∼2 s, respectively, switching to n-type behavior when exposed to NO with a response and recovery time of ∼20 and ∼250 s, respectively. Analyte gas concentrations from 0 to 220 ppm were taken for analysis. Selectivity analysis at room temperature revealed NO's superior response of ∼20% above 180 ppm, compared to SO's < 3% response at 180 ppm. NO achieved its highest response (∼45%) at 30 ppm and remained constant above 80 ppm, while SO peaked at ∼30% at 60 ppm but declined with increasing flow rates. Further, the increasing temperature led to an amplified response for NO, whereas SO showed an increase in response after 180 °C. SO exhibited a significant response of ∼70% from 140 °C onward. Additionally, NO showed distinct peaks at 160, 250, and 290 °C with responses of 50, 65, and 80%, respectively. The calculated limit of detection values were 236 ppm for NO, 644.07 ppm for SO, 401.32 ppm for NO, and 496.86 ppm for SO.