Recent advances in SnO2 nanostructure based gas sensors

The detection of low-concentration gases and odors in fields such as healthcare, mobility, and indoor environment control is attracting tremendous attention. The development of high-sensitivity gas sensors capable of detecting low concentrations of gases and molecules is strongly desired. This review focuses on tin oxide nanomaterials, which are substances that are being actively researched as semiconductor-type gas sensors. In particular, the development of novel tin oxide nanomaterials over the last decade and their gas sensing applications are discussed. It is revealed that dimension and morphology affect the sensing performance. Tin oxide nanomaterials having nano-meter size which is similar to size of a depletion layer, and controlled microstructure such as a nanosheet structure shows high sensing performance. The dendritic structure in which 2D nanosheets are connected by crystal growth points the direction for future sensor development. Furthermore, the high gas adsorption performance and reactivity of the metastable crystal plane will be a guide for future sensor development.