Nanocrystalline SnO2 and In2O3 as materials for gas sensors: The relationship between microstructure and oxygen chemisorption

Synthesis, Structure, and Sensor Properties of Vanadium Pentoxide Nanorods

“…It was found that the interaction of the nanorods with molecular oxygen is not reversible, because of the oxidation of vanadium(IV) at the nanorod surface; we have previously observed the same process for vanadium oxide nanotubes 4. Above 150 °C the resistance of the material raises quickly and reaches a plateau 27,28. The decrease of the oxygen concentration was detected at a permanent flow chromatographically and the resistance of the sample reached a plateau.…”

Nanocrystalline BaSnO3 as an Alternative Gas Sensor Material: Surface Reactivity and High Sensitivity to SO2

“…From the conductance dependence on O 2 partial pressure the predominant type of ionosorbed oxygen was estimated. To perform it, the data were treated using the ionosorption model developed in [36,37]. According to this, the ionosorption can be considered as the gas molecule interaction with charge carriers at the semiconductor surface: $\frac{\beta }{2}{O}_{2,gas}+\alpha e^{-}=O_{\beta ,surf}^{\alpha -}$…”

“…Applying complicated expressions for surface coverage to two model approximations, the conductance should be linearly dependent on oxygen partial pressure in logarithmic coordinates [37] $\text{(i) for small crystallites:} \lg \sigma -\lg false(1-\sigma /{\sigma }_0)=const-m\cdot \lg pfalse(O_{2}false)$ $\text{(ii) for large crystallites:} \lg \sigma -\frac{1}{2}\lg \{\ln false(\sigma /{\sigma }_0)\}=const-m\cdot \lg pfalse(O_{2}false)$ where σ is conductance in presence of oxygen and σ 0 is conductance in Ar in absence of oxygen. The approximation (i) is applied to fully depleted semiconductor particles with radius less than Debye length, while the case (ii) refers to large enough particles with size larger than Debye length and, hence, with the separation between depleted surface and not depleted bulk regions.…”

Sensing Properties of Tin Acetylacetonate-Based Thin Films Doped with Platinum

“…Several references deal with the calculation of activation energy on oxidic materials of the active layer (tin oxide, titanium dioxide, indium sesquioxide with catalysts). (10)(11)(12) To the best of our knowledge, no estimation of activation energy for layers based on acetylacetonates has been published to date. In this manuscript, the activation energy was computed by solving the model of the first-order reaction according to ref.…”