Solid State Electronic Sensors for Detection of Carbon Dioxide

Ami Hannon; Jing Li

doi:10.3390/s19183848

Solid State Electronic Sensors for Detection of Carbon Dioxide

Sensors (Basel). 2019 Sep 6;19(18):3848. doi: 10.3390/s19183848.

Authors

Ami Hannon¹, Jing Li²

Affiliations

¹ KBR Wyle Inc. at NASA Ames Research Center, CA 94035, USA.
² NASA Ames Research Center, CA 94035, USA. jing.li-1@nasa.gov.

Abstract

Detection of carbon dioxide (CO₂) is very important for environmental, health, safety and space applications. We have studied novel multiwall carbon nanotubes (MWCNTs) and an iron oxide (Fe₂O₃) nanocomposite based chemiresistive sensor for detection of CO₂ at room temperature. The sensor has been miniaturized to a chip size (1 cm × 2 cm). Good sensing performance was observed with a wide detection range of CO₂ concentrations (100-6000 ppm). Structural properties of the sensing materials were characterized using Field-Emission Scanning Electron Microscopy, Fourier-Transform Infrared and Raman spectroscopies. The greatly improved sensitivity of the composite materials to CO₂ can be attributed to the formation of a depletion layer at the p-n junction in an MWCNT/iron oxide heterostructure, and new CO₂ gas molecules adhere to the high surface area of MWCNTs due to the concentration gradient. The test results showed that the CO₂ sensor possesses fast response, compact size, ultra-low power consumption, high sensitivity and wide dynamic detection range.

Keywords: CO2 sensor; carbon dioxide sensor; chemiresistive sensor; electronic nose; functionalized nanotubes; gas sensor; nanocomposite; room temperature gas sensing; smartphone sensor.