SnO2(Au0, CoII,III) nanocomposites: A synergistic effect of the modifiers in CO detection

Nanocrystalline SnO₂ has been synthesized and its surface has been modified with Au⁰ and Co(II, III). The distribution of the modifiers over the nanocomposites has been studied by X-ray diffraction, inductively coupled plasma mass spectrometry, and transmission electron microscopy. The effect of the modifiers on the hydrogen reduction of nanocrystalline SnO₂ has been assessed. The CO sensing properties of the synthesized materials (10 ppm CO in air) have been studied in situ by electrical conductance measurements. The addition of both Au⁰ and Co(II, III) allows the working temperature of the SnO₂-based semiconductor sensor to be lowered to 215°C.