Journal
CHEMICAL SCIENCE
Volume 13, Issue 20, Pages 6089-6097Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/d2sc01738e
Keywords
-
Categories
Funding
- Engineering and Physical Sciences Research Council [EP/R512400/1, SI-25766]
Ask authors/readers for more resources
In this study, the nature of interactions between SnO2 and O-2 in conductometric gas sensors (CGS) was investigated. Results showed a correlation between the dynamically changing surface oxygen vacancies and the resistance response in SnO2-based CGS. It was concluded that surface oxygen vacancies, rather than the observed oxygen adsorbates, are central to response generation in SnO2-based gas sensors.
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 O-2, 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 SnO2-x as a function of O-2 pressure. Our results reveal a correlation between the dynamically changing surface oxygen vacancies and the resistance response in SnO2-based CGS. While oxygen adsorbates were observed in this study we conclude that these are an intermediary in oxygen transport between the gas phase and the lattice, and that surface oxygen vacancies, not the observed oxygen adsorbates, are central to response generation in SnO2-based gas sensors.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available