SiC Foams Decorated with SnO₂ Nanostructures for Room Temperature Gas Sensing

Abstract

Cell 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.

Metal Oxide Nanowire Preparation and Their Integration into Chemical Sensing Devices at the SENSOR Lab in Brescia

“…In 2014 two reports were published on the growth of SnO 2 nanowires using evaporation condensation with SnO 2 powder as source material but a different catalyst was used to grow the nanowires. In the first report, the authors showed the results of SnO 2 nanowires grown on SiC substrate using Au as a catalyst [43]. Deposition parameters (E t = 1370 °C, P = 100 mbar, S t = 500 °C) were similar to those first reported by Comini et al [36].…”

Chemical Gas Sensors Studied at SENSOR Lab, Brescia (Italy): From Conventional to Energy-Efficient and Biocompatible Composite Structures

“…As previously reported by our group (Figure 11a), the desorption process under UV light is faster than in dark, leading to a complete recovery of the baseline. In most cases, there is no memory effect at temperatures higher than 250 °C [94]. At RT, the enhancement of the response by UV-irradiation is clearly visible, as reported in Figure 11b.…”

“…For example, in the case of UV-irradiated SnO 2 RGTO, the best results for the detection of CO were obtained at 15 mW/m 2 . At higher values of applied power, the response is lower or comparable to the dark response, due to the prevalence of the photodesorption effect [94].…”

“…values of applied power, the response is lower or comparable to the dark response, due to the prevalence of the photodesorption effect [94].…”

“…(b) Response in dark-and UV-irradiation condition for the tin-oxide RGTO (rheotaxial growth thermal oxidation) samples gold-catalyzed as a function of the working temperature toward 100 ppm of CO at 30% of relative humidity. Reproduced with permission[94].…”