A pulse-driven sensor based on ordered mesoporous Ag2O/SnO2 with improved H2S-sensing performance

Abstract Ordered mesoporous Ag 2 O/SnO 2 was synthesized via nanocasting method using hexagonal mesoporous SBA-15 as template. As-prepared Ag 2 O/SnO 2 samples were characterized by X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy, energy-dispersive X-ray analysis, and X-ray photoelectron spectroscopy. A microspheric directly heated gas sensor based on the mesoporous Ag 2 O/SnO 2 was fabricated, and its gas sensing performance was investigated. Results indicated that the sensor based on mesoporous Ag 2 O/SnO 2 exhibited excellent selectivity, high response, and good stability to H 2 S at 100 °C. A pulse-driving method was then introduced to enhance the sensitivity to H 2 S. Under pulse-driving, the response of the sensor to 300 ppb H 2 S was 5.7, which was approximately two times higher than that under constant current, and the limit of detection was improved to 50 ppb. The high-sensing performance of the sensor was attributed to the composition and structure of mesoporous Ag 2 O/SnO 2 and the pulse-driven mode.