Functionalized multi-walled carbon nanotubes network sensor for NO2 gas detection at room temperature

The chemical gas sensor was fabricated using a functionalized Multi-Walled Carbon Nanotubes (MWCNTs-OH) suspension and deposited on filter cake to employ the filtration from suspension (FFS) method. The fabricated gas sensor was investigated to NO2 gas detection at room temperature. The structural and morphological properties of the MWCNTs film were characterized using an X-ray diffractometer and an atomic force microscope, which confirmed that the film properties are changed when exposed to NO2 gas. A homemade sensing system was used to evaluate the sensitivity of the fabricated network toward NO2 gas at ppm levels by changing the concentration of (32, 72, and 108). MWCNTs-OH network showed a decrease in resistance upon exposure to the NO2 gas in comparison with air. The sensor demonstrated a good sensitivity of about 64% at 32ppm for a low concentration of NO2 gas at room temperature, while this value is reduced whenever exposed to NO2 gas for a long time.