Metal Oxide Gas Sensors from Design to Real Applications: The Case Study of TixSn1-xO2 Solid Solutions

This review work reports the synthesis, the morphological, structural, spectroscopic, and electrical properties, the sensing performances of TiSnO solid solutions, using pristine SnO and TiO as reference. Each characterization highlighted two behavioral classes for the solid solutions: SnO-like and TiO-like, being the oxide with x = 0.25 the borderline sample. Furthermore, two real applications of (Ti, Sn) solid solutions are described: i) in air quality monitoring to detect carbon monoxide (CO), ii) to detect the variation of analytes concentrations in samples of hydraulic fluid headspace collected during the system running.