Exploitation of Unique Properties of Zeolites in the Development of Gas Sensors

Abstract

The unique properties of microporous zeolites, including ion-exchange properties, adsorption, molecular sieving, catalysis, conductivity have been exploited in improving the performance of gas sensors. Zeolites have been employed as physical and chemical filters to improve the sensitivity and selectivity of gas sensors. In addition, direct interaction of gas molecules with the extraframework cations in the nanoconfined space of zeolites has been explored as a basis for developing new impedance-type gas/vapor sensors. In this review, we summarize how these properties of zeolites have been used to develop new sensing paradigms. There is a considerable breadth of transduction processes that have been used for zeolite incorporated sensors, including frequency measurements, optical and the entire gamut of electrochemical measurements. It is clear from the published literature that zeolites provide a route to enhance sensor performance, and it is expected that commercial manifestation of some of the approaches discussed here will take place. The future of zeolite-based sensors will continue to exploit its unique properties and use of other microporous frameworks, including metal organic frameworks. Zeolite composites with electronic materials, including metals will lead to new paradigms in sensing. Use of nano-sized zeolite crystals and zeolite membranes will enhance sensor properties and make possible new routes of miniaturized sensors.

Diseño Y Construcción De Sensores Automatizados De Gases De Efecto Invernadero en La Baja Troposfera

“…Estos sensores, que se basan en las propiedades electroquímicas o modulación de la resistencia eléctrica del material expuesto a diferentes gases, han venido tomando importancia en el monitoreo de la polución del aire [12], [13].…”

Potential uses of natural zeolites for the development of new materials: short review

“…2) and ion exchange properties. The processes that include formation of complex-cations on zeolites are important to develop industrially significant materials, such as catalysts [10][11][12] and photocatalysts [13], medicine [14], sensor materials [31,32], feeding additives for farm animals [33], etc.…”

Nanostructured Ag-zeolite Composites as Luminescence-based Humidity Sensors

“…3,4 The latter properties confer to silver-zeolite composites the ability to optically respond to external stimuli, such as variations of moisture within the zeolite scaffold [6][7][8] or the presence of determined gases; therefore their use as water vapor and gas sensors has been suggested. 9,10 In a recent study we have demonstrated that the optical response of Ag-zeolites to moisture is not only correlated to changes in the absorption or quenching of their emission but also to the appearance of different emission colors with respect to their water content. 5 The stabilization of silver clusters in partially Li exchanged LTA zeolites led to the formation of a moisture-responsive material in which changes in the relative low humidity scale were reflected in a dynamic color change from a blue to green/yellow emission in dehydrated and hydrated samples, respectively.…”