Response Modeling of Temperature Modulated Array of Chromium Doped Nanostructured TiO2 Gas Sensors

AbstractThe aim of this work is to demonstrate that thermal modulation improves the selectivity of TiO2 –based resistive-type gas sensors. Sensor array, operating upon sinusoidal temperature profile over a temperature range of 240 – 300°C, is comprised of nanocrystalline TiO2:Cr (0.1–10 at.% Cr) semiconductors switching from n-type to p-type at about 1 at.% Cr. Electrical resistance responses to reducing and oxidizing gases such as NO, NO2, H2, CH4, C3H8 (0 – 3000ppm) are dynamically recorded and compared in order to assess cross-sensitivity as well as humidity interference. Theoretical model developed for simple gas-solid interactions is extended to hydrogen