TiO2-SnO2 Nanocomposites as Semiconductor Gas Sensors for CO and NOx Detection

Abstract

Gas sensors based upon semiconductor metal oxides provide for the safe detection of toxic gases, such as carbon monoxide in households, natural gas in coal mines, and ethanol in fermentation processes. However, they still suffer from several limitations, such as long-term response reproducibility and gas sensitivity and selectivity. The need for thermally stable gas sensor materials that possess ultrahigh sensitivity and selectivity, often in the presence of other adsorbing gases, presents a major challenge. In this work, we have worked on Tin Surface modified Titanium dioxide (TiO₂-SnO₂) nanocomposites that exhibited superior thermal stability against grain growth. TiO₂-SnO₂ nanocomposites achieved superb sensitivity for both reducing and oxidizing gases. TiO₂-SnO₂ thick film sensor gives highest selectivity to NO₂ gas which is detection of toxic or combustible gases at parts per million levels.