An ab initio study of oxygen adsorption on tin dioxide

In spite of detailed experimental and theoretical studies, a definitive model of oxygen adsorption on the surface of SnO2 has yet to emerge. In this study, density functional theory (DFT) calculations were performed to simulate various potential scenarios for oxygen placement on the planar reduced SnO2 (1 1 0) surface. Models for four adsorbate species that have been experimentally observed are hence proposed. Most importantly, these include the species labelled as 'O2-' and 'O−' in classical gas sensor theory, which are directly concerned with the gas sensing action of SnO2.