Selectivity of an Ag/BTO-Based Nanocomposite as a Gas Sensor Between NO₂ and SO₂ Gases

The novel Ag/BTO/TiO2 nanocomposite was assessed for its gas-sensing capabilities toward hazardous gases NO2 and SO2. It exhibited p-type behavior with increasing resistance for SO2 with a response and recovery time of similar to 5 and similar to 2 s, respectively, switching to n-type behavior when exposed to NO2 with a response and recovery time of similar to 20 and similar to 250 s, respectively. Analyte gas concentrations from 0 to 220 ppm were taken for analysis. Selectivity analysis at room temperature revealed NO2's superior response of similar to 20% above 180 ppm, compared to SO2's < 3% response at 180 ppm. NO(2(VC) )achieved its highest response (similar to 45%) at 30 ppm and remained constant above 80 ppm, while SO2(VC) peaked at similar to 30% at 60 ppm but declined with increasing flow rates. Further, the increasing temperature led to an amplified response for NO2, whereas SO2 showed an increase in response after 180 degree celsius. SO2(VC) exhibited a significant response of similar to 70% from 140 degree celsius onward. Additionally, NO2(VC) showed distinct peaks at 160, 250, and 290 degree celsius with responses of 50, 65, and 80%, respectively. The calculated limit of detection values were 236 ppm for NO2, 644.07 ppm for SO2, 401.32 ppm for NO2(VC), and 496.86 ppm for SO2(VC).