Effect of Nanoparticle Interaction on Structural, Conducting and Sensing Properties of Mixed Metal Oxides

Abstract

This review analyzes the studies published, mainly in the last 10–15 years, on the synthesis, structure, and sensor properties of semiconductor nanocomposites. Particular attention is paid to the interaction between nanoparticles of the sensitive layer, and its effect on the structure, sensitivity, and selectivity of semiconductor sensor systems. Various mechanisms of interaction between nanoparticles in metal oxide composites are considered, including the incorporation of metal ions of one component into the structure of another, heterocontacts between different nanoparticles, and core–shell systems, as well as their influence on the characteristics of gas sensors. The experimental data and studies on the modeling of charge distribution in semiconductor nanoparticles, which determine the conductivity and sensor effect in one- and two-component systems, are also discussed. It is shown that the model which considers the interactions of nanoparticles best describes the experimental results. Some mechanisms of detection selectivity are considered in the conclusion.

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

“…The bond of the resulting atoms with defects leads to an increase in the energy required for oxygen desorption and its transition from ZnO particles to In 2 O 3 particles, which determines the conductivity of the composite. Therefore, the sensitization of the sensor response by ZnO nanoparticles is manifested in such composites at higher temperatures than in mixtures of commercial nanopowders and is more effective due to the high concentration of defects [ 11 ].…”

“…The conductive and sensor properties of binary metal oxide composites largely depend on the synthesis method, which can affect the type of interaction between the nanoparticles of the system (see, for example, Refs. [ 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 ].…”

Dependence of n-Type Metal-Oxide Gas Sensor Response on the Pressure of Oxygen and Reducing Gases

“…This result cannot reproduce the experimental measures performed, for example, by Barsan and Weimar in ref, which strongly suggests that S also depends on the oxygen partial pressure ( p O 2 ). Furthermore, eq indicates that S also depends on the grain size through σ s . − …”

Microflowers Composed of VO2 Nanoflakes for Selective Detection of Acetone and Ammonia

“…However, they typically operate at high temperatures and show a poor gas selectivity. A number of strategies such as surface functionalization, hierarchical structuring, and elemental doping have been employed to enhance the sensing performance of MOS-based gas sensors and overcome these drawbacks. − Recently, phase modulation has attracted special attention in adjusting the sensing capability of semiconductor oxides toward different gases because it can trigger significant changes in the physical and chemical properties by altering the atomic configuration between different microscopic crystalline phase structures of the same sensing oxide. − …”