Gas-sensitive properties of thin and thick film sensors based on Fe2O3–SnO2 nanocomposites

Influence of phase composition, structural peculiarities and grain size of Fe2O3–SnO2 nanocomposites prepared by sol–gel technology on gas-sensitive properties of the corresponding gas sensors has been studied in the paper. The characteristics of thin film sensors were obtained with regards to NO2 and C2H5OH. Behaviour of thick film sensors was estimated in humid C2H5OH ambient. High sensitivity of Fe2O3–SnO2 samples containing highly dispersive Fe2O3 phase has been revealed. The composites consisting of poorly crystallised α-Fe2O3 along with Sn(IV)–α-Fe2O3 solid solution demonstrate maximum sensitivity to ethanol. Structural and functional distinctions of the Fe2O3–SnO2 composites obtained by using different Fe-precursors (Fe3+ and Fe2+ inorganic salts) have been revealed. Mechanisms of the processes, which determine gas-sensitive behaviour of the composites, are considered.