Abstract

Changes in the resistivity of polycrystalline V-doped TiO₂ upon exposure to SO₂ in air allow application of the material as a sensor for detection of this important pollutant. Optimal sensitivity to SO₂ is achieved at low doping levels, where there is also good selectivity relative to CO and CH₄. Concentration of SO₂ as low as 10 ppm produce a 10% change in the resistance of 0.5% V-doped TiO₂, allowing facile detection of the gas at this level. Analysis of the kinetics of the resistance changes for 1% V-doped TiO₂ as a function of temperature shows that the rate of initial response is only weakly activated.