(Ti,Sn) solid solutions as functional materials for gas sensing

Metal-oxide semiconductors are widely used as functional materials for gas sensing because of theirchemoresistive effect when interacting with ambient gases. For this work, nanosized TixSn1-xO2havebeen synthesized at increasing Ti molar ratio (x = 0, 0.1, 0.2, 0.25, 0.3, 0.5, 0.7, 0.8, 0.9, 0.95, 1) and exten-sively investigated through a wide variety of characterizations. It turned out that the merging process ofthe two single oxides formed new compounds with improved gas responses compared to pure TiO2andalso to pure SnO2. Moreover, all investigated physico-chemical characteristics resulted tuneable throughthe titanium content in the solid solution. Each characterization carried out onto TixSn1-xO2solid solu-tions made it possible to identify two classes of materials with SnO2-like or TiO2-like behaviours, thebest CO response being on the intersection of the two species of materials. Moreover, a very interestinganalysis on the generally accepted electrical transport model through polycrystalline semiconductorshas been carried out. Indeed, the comparison with experimental evidences has highlighted a conductionmechanism not previously considered.