Promising designs of gas analyzers for metallurgy

Gas analysis is one of the key methods for assessing the quality of atmospheric air in populated areas, as well as in the work area of production facilities. Atmospheric air monitoring is especially necessary at facilities that have a significant negative impact on the environment, in parti­cular, at ferrous metallurgy enterprises. The peculiarities of the gas analyzers used for air quality monitoring system are their sensitivity and selectivity. To achieve these indicators, a properly selected sensing element is needed: a gas analyzer converter. Synthesized solid solutions of semiconductor binary components, which proved themselves to be good adsorbents, are proposed as materials for the manufacture of converters. In this paper, the authors examined semiconductor systems consisting of ZnTe and CdSe, conditions for synthesis of the solid solutions based on them, and methods for their identification, which allowed the obtained materials to be certified as solid substitution solutions with cubic spha­lerite and hexagonal wurtzite structures (depending on the composition). X-ray, micro-, electron-microscopic, and IR spectroscopic studies of solid solutions made it possible to understand the surface structure of adsorbents. Results of the studies of the surface chemical composition, acid-base properties of solid solutions and binary components of the system allow us to conclude that the Lewis and Brønsted acid centers responsible for CO adsorption on the surface are present on the surface. In the ZnTe – CdSe systems, there is a tendency to move from a slightly acidic region to a relative increase in the surface basicity with an increase in ZnTe content. When materials are placed in a CO atmosphere, gas adsorption on the surface of solid solutions occurs in the same dependence, which was confirmed by the direct catalytic studies. The established patterns of changes with the composition of bulk and surface properties allow us to recommend new obtained materials as primary converters of sensors.