Design and analysis of functional multiwalled carbon nanotubes for infrared sensors

• This paper demonstrates the comparison of fast and sensitive infrared detection using chemically modified multiwalled carbon nano-tubes (MWCNTs).
• Functionalized nanotubes have a high impact on radiation sensing.
• Infrared sensors based on chemically modified buck papers/films of nanotubes had significant sensitive response.

In this paper, we report the comparison of infrared detection based on buckypapers of chemically modified multiwalled carbon nanotubes by carboxyl and thiol groups. We observed that functionalized carbon nanotube buckypapers had a significant impact on radiation sensing at room temperature. Nanotubes buckypapers were formed by successively increasing cross-linker reagent in carbon nanotubes. It was observed that infrared sensitivity of resistively read-out of carboxylated and thiolated buckypapers increased by increasing the cross-linker reagent up to certain limit. Further increase in cross-linker reagent results in brittleness of buckypaper. The maximum sensitivity of carboxylated and thiolated buckypapers was 3.4% and 16.07% while minimum response time of carboxylated and thiolated buckypapers was 1.29 s and 6.09 s, respectively. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and Fourier transform infrared spectroscopy were used for analysis of presences of nanotubes, structural morphology and defect density to evaluate all the modifications of the nanotubes structure and the nature of the compounds added to the nanotubes surface by functionalization treatment.