Sensor Properties of Nanostructured Systems Based on Indium Oxide with Co3O4 or ZrO2 Additives

• Published in: Russian journal of physical chemistry. B 2018, Vol.12 (1), p.129-134
• Main Authors: Gromov, V. F., Gerasimov, G. N., Belysheva, T. V., Ikim, M. I., Spiridonova, E. Yu, Grekhov, M. M., Ali-zade, R. A., Trakhtenberg, L. I.
• Format: Article
• Language: English
• Subjects: Additives; Chemistry; Chemistry and Materials Science; Cobalt oxides; Composite materials; Electric and Magnetic Properties of Materials; Indium oxides; Nanostructure; Physical Chemistry; Zirconium dioxide
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793118010062

The effect of Co 3 O 4 and ZrO 2 additives on the sensory response of In 2 O 3 -based nanostructured composites to H 2 and CO is studied. It is shown that the addition of small amounts of Co 3 O 4 or ZrO 2 to In 2 O 3 leads to a sharp increase in the sensory response to hydrogen. The maximum sensory response of the ZrO 2 −In 2 O 3 composite to 1100 ppm of hydrogen increases from 80 to 270 as the ZrO 2 content changes 0 to 20 wt %. The response to CO varies only slightly. For Co 3 O 4 −In 2 O 3 composites, the maximum response to H 2 and CO increases with the Co 3 O 4 content within 0−10 wt %. A further increase in the Co 3 O 4 content leads to a significant decrease in the response, with composites containing ∼60 wt % Co 3 O 4 being characterized by a very low efficiency. In the Co 3 O 4 −In 2 O 3 system with a content of up to 60 wt % Co 3 O 4 , electronic conduction is realized, which changes to hole conduction at Co 3 O 4 within 80−100 wt %. In the ZrO 2 −In 2 O 3 system, electric current flows through In 2 O 3 nanocrystals, i.e., n -type conduction takes place. Possible reasons for the observed effects are discussed.