Direct in situ spectroscopic evidence of the crucial role played by surface oxygen vacancies in the O₂-sensing mechanism of SnO₂.

ABSTRACT: Conductometric gas sensors (CGS) provide a reproducible gas response at a low cost but their operation mechanisms are still not fully understood. In this paper, we elucidate the nature of interactions between SnO₂, a common gas-sensitive material, and O₂, a ubiquitous gas central to the detection mechanisms of CGS. Using synchrotron radiation, we investigated a working SnO₂ sensor under operando conditions via near-ambient pressure (NAP) XPS with simultaneous resistance measurements, and created a depth profile of the variable near-surface stoichiometry of SnO_2-x as a function of O₂ pressure. Our results reveal a correlation between the dynamically changing surface oxygen vacancies and the resistance response in SnO₂

SUBMITTER: Kucharski S 

PROVIDER: S-EPMC9132051 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature