Work

Interplay between CO and Surface Lattice Oxygen Ions in the Vacancy-Mediated Response Mechanism of SnO2-Based Gas Sensors

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Despite having been commercially available for more than half a century, conductometric gas sensors still lack a definite description of their operation mechanism, which hinders research into improving their characteristics. With the advent of operando spectroscopy comes the opportunity to elucidate their working principle by observing their surface during sensing. To that end, we have employed near-ambient pressure (NAP) XPS with simultaneous resistance measurements to correlate the macroscopic sensor response with atomistic changes to the sensor’s surface under exposure to CO, a common target gas. Our results show a clear relationship between the sensor response and the change in surface stoichiometry of SnO 2, suggesting that near-surface oxygen vacancies play a vital role in the sensing mechanism, in support of a vacancy-modulated “surface conductivity” mechanism.

Source: ACS Sensors

DOI: 10.1021/acssensors.4c03047

Authors: Stefan Kucharski, Michael Vorochta, Lesia Piliai, Andrew M. Beale, Christopher Blackman

Institutions: Rutherford Appleton Laboratory, Research Complex at Harwell, University College London, Charles University

Language: English

Topic: Gas Sensing Nanomaterials and Sensors

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Grantová Agentura České Republiky, Engineering and Physical Sciences Research Council