Impedance spectroscopy in H2 sensing with TiO2/SnO2 nanomaterials

Abstract

Alternating current a.c. measurements enable to understand the physical and chemical processes occurringin semiconductor materials. Impedance spectroscopy has been successfully applied to study the responsesof gas sensors based on metal oxides, such as TiO2, SnO2and TiO2/SnO2nanocomposites. This workis devoted to dynamic measurements of hydrogen sensor behaviour over the temperature range of 300–450◦C. Frequency dependence of the impedance signal gives evidence that 50 mol% TiO2/50 mol% SnO2nanocomposites should be treated as resistive-type sensors. Temporal evolution of the response to 500 ppmH2at 320◦C indicates a very short response time and much longer recovery.

Keywords

• impedance spectroscopy
• tio2
• sno2
• hydrogen detection
• resistive-type gas sensors