Spectroscopic Insight into the Role of Surface Oxygen Vacancies in the Detection of NO₂ in SnO₂-Based Chemoresistive Gas Sensors.

ABSTRACT: Despite widespread use of SnO₂-based conductometric gas sensors, the sensing of NO₂ remains poorly described on the atomic scale, limiting the design of next-generation sensors. Here, near-ambient-pressure X-ray photoelectron spectroscopy combined with in situ resistance measurement was used to investigate the interaction between NO₂ and a SnO₂-based sensor at room temperature and 300 °C. Through stepwise exposure and evacuation cycles, we tracked real-time changes in the O/Sn atomic ratio and electronic structure alongside the macroscopic resistance response. Exposure to NO₂ consistently increased the O/Sn ratio, indicating the healing of surface oxygen vacancies, and this effect directly correlated with an increase in resistance. At

SUBMITTER: Kucharski S 

PROVIDER: S-EPMC12836335 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature