Atomistic Descriptions of Gas-Surface Interactions on Tin Dioxide

Chemosensors

Chris Blackman¹  Stefan Kucharski¹ 

[1] Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK;

关键词: SnO₂;    sensor;    mechanism;    operando;    spectroscopy;    adsorbates;   

DOI  :  10.3390/chemosensors9090270

来源: DOAJ

【 摘 要 】

Historically, in gas sensing literature, the focus on “mechanisms” has been on oxygen species chemisorbed (ionosorbed) from the ambient atmosphere, but what these species actually represent and the location of the adsorption site on the surface of the solid are typically not well described. Recent advances in computational modelling and experimental surface science provide insights on the likely mechanism by which oxygen and other species interact with the surface of SnO₂, providing insight into future directions for materials design and optimisation. This article reviews the proposed models of adsorption and reaction of oxygen on SnO₂, including a summary of conventional evidence for oxygen ionosorption and recent operando spectroscopy studies of the atomistic interactions on the surface. The analysis is extended to include common target and interfering reducing gases, such as CO and H₂, cross-interactions with H₂O vapour, and NO₂ as an example of an oxidising gas. We emphasise the importance of the surface oxygen vacancies as both the preferred adsorption site of many gases and in the self-doping mechanism of SnO₂.

【 授权许可】

Unknown