(Ti, Sn)O2 solid solutions for gas sensing: a systematic approach towards calcination temperature and molar composition

Titanium-Tin solid solutions TixSn1-xO2 (x = 0.1, 0.3, 0.5, 0.7, 0.9) were prepared by symplectic gel co-precipitation (SGC) method from stoichiometric hydroalcoholic solutions of Ti and Sn metalalkoxides. Structural, optical and electrical analyses performed and the results have been correlated. It turned out that the peaks of the XRD patterns move from the position of SnO2 cassiterite to TiO2 rutile, when increasing the Ti content. FT-IR investigations on the changes induced by CO interaction revealed the increase of a broad electronic absorption in the medium IR region already at RT for pure SnO2 and Ti0.1Sn0.9O2 which is absent in pure rutile TiO2 as well as in other examined solid solutions. Both photoluminescence and electrical characterizations are in agreement with this result