Synthesis, Structural and Sensor Properties of Nanosized Mixed Oxides Based on In2O3 Particles

Abstract

The paper considers the relationship between the structure and properties of nanostructured conductometric sensors based on binary mixtures of semiconductor oxides designed to detect reducing gases in the environment. The sensor effect in such systems is determined by the chemisorption of molecules on the surface of catalytically active particles and the transfer of chemisorbed products to electron-rich nanoparticles, where these products react with the analyzed gas. In this regard, the role is evaluated of the method of synthesizing the composites, the catalytic activity of metal oxides (CeO2, SnO2, ZnO), and the type of conductivity of metal oxides (Co3O4, ZrO2) in the sensor process. The effect of oxygen vacancies present in the composites on the performance characteristics is also considered. Particular attention is paid to the influence of the synthesis procedure for preparing sensitive layers based on CeO2–In2O3 on the structure of the resulting composites, as well as their conductive and sensor properties.

Structure, Conductivity, and Sensor Properties of Nanosized ZnO-In2O3 Composites: Influence of Synthesis Method

“…The magnitude of the sensor response of hydrothermal ZnO-In 2 O 3 composites containing up to 20% zinc oxide is significantly influenced by the fact that during the synthesis of such composites, a change in the phase composition of In 2 O 3 , namely the transition of the cubic to the rhombohedral phase, occurs. Earlier, we found that the introduction of cerium into indium oxide, leading to its phase changes, causes a sharp drop in the sensor response to hydrogen compared with pure indium oxide [ 36 ]. The introduction of zinc into cubic indium oxide also leads to an increase in the response to NO 2 compared with the undoped sample [ 33 ].…”

“…[ 7 , 8 , 9 , 10 , 11 , 12 ]). The most important types of interaction affecting the sensor response in binary nanosystems include the transfer of atomic oxygen between catalytically active and electron-rich nanoparticles, as well as the introduction of ions of particles of one oxide into the other component [ 13 , 14 , 15 , 16 ].…”

Dual functional In2O3-PANI-PEDOT Hybrid for Sensing Gallic Acid and Photocatalytic Degradation of Methylene Blue

“…Nanostructured metal oxides have emerged as promising materials for sensor applications due to their ability to modulate conductivity in response to trace concentrations of gases in the atmosphere. These sensors have demonstrated efficacy in detecting various pollutants, including toxic gases and volatile organic complexes in the air, such as ammonia, CO, NO2, H2, benzene, methane, and ethanol Wang et al 2021;Hu et al 2018;Wang et al 2022;Han et al 2015;Ikim et al 2023]. The metal oxides, such as indium oxide (In2O3), stand out for their favorable properties, such as a small band gap, high electron concentration, and mobility [Nunes et al 2019;Wang et al 2018].…”