Investigating the sensor response of ceria-containing binary metal oxide nanocomposites

Abstract

The hydrogen sensing performance of ceria-containing nanocrystalline indium and tin oxides is investigated for different concentrations of added ceria. The sensor response of nanocrytsalline In₂O₃ is considerably enhanced at low CeO₂ concentrations. In contrast, low levels of CeO₂ cause a substantial drop in the sensor response of SnO₂-based composite; at a 3 wt % level of added ceria, its hydrogen sensing ability is almost entirely suppressed. Possible causes of these effects are investigated via X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. XPS data show that additions of CeO₂ have different effects on the structure of the base oxides (In₂O₃ and SnO₂), with implications for the hydrogen sensing performance of the composites.