1,721,575 research outputs found
SiC Foams Decorated with SnO2 Nanostructures for Room Temperature Gas Sensing
No full textSberveglieri, Giorgio/0000-0003-0080-8117; Ponzoni, Andrea/0000-0001-9955-5118; Comini, Elisabetta/0000-0003-2559-5197; Vakifahmetoglu, Cekdar/0000-0003-1222-4362Cell walls of the commercial silicon carbide (SiC)-based foams were decorated by one-dimensional tin dioxide (SnO2) nanostructures. Thermal evaporation of SnO2 powder with the assistance of a Au catalyst in inert atmosphere caused the formation of SnO2 nanobelts on the pore surfaces. The room temperature (RT) ammonia (NH3) and nitrogen dioxide (NO2) gas sensing behaviors were investigated systematically in both dry and humid air atmosphere with/without UV activation. The results were compared to those for bare SnO2 and SiC. It was shown that SiC/SnO2 composite was efficient to detect low concentration of NH3 (10-50 ppm) and NO2 (1-5 ppm) under humid air and UV activation at RT.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [CAYDAG-113Y533]The author wishes to express sincere appreciation to Prof. Gian Domenico Soraru and his team in University of Trento for the N2 adsorption and desorption data. C. V. gratefully acknowledge the support of TUBITAK (The Scientific and Technological Research Council of Turkey) under the project Grant No. CAYDAG-113Y533
Papers Presented At The Workshop On New Development In Semiconducting Gas Sensors, Castro-Marina, Italy, September 13-14 1993
No full text
Recent developments in semiconducting thin films for gas sensors
No full textA critical review of thin-film semiconducting materials that are used as gas sensors is presented in this paper. These materials can be approximately divided into two main groups: the first includes sensors that detect oxygen with variations of bulk or surface conductance; the second comprises all the materials that detect oxidizing and reducing gases in air at constant oxygen partial pressure by means of surface-conductance variations. The oxygen-detection mechanisms of surface- and bulk-conductance sensors are described. The long-term stability and the selectivity to a particular species are the main properties of a reliable gas sensor; these properties are also discussed in detail in relation to the second group of sensors. The properties of tin oxide, the most investigated material for gas sensing, are reviewed; some new ternary semiconducting compounds are also presented, together with their growth techniques. An almost novel method for growing thin films, the RGTO (rheotaxial growth and thermal oxidation) technique will be presented, since it is capable of preparing mixed oxide thin films with high surface area and nanosized crystallites. It is well known that the main possibility for sensor development lies in device arrays; therefore, the utilization of different materials for gas detection and the measurement techniques of signals supplied by sensor arrays will be outlined
- …
