Efficient vapor sensors using foils of dispersed nitrogen-doped and pure carbon multiwalled nanotubes.

We fabricated vapor sensors using nitrogen-doped (CNx) and pure multi-walled carbon nanotubes (MWNTs), and compared their performance. The sensors were constructed by dispersing the nanotube materials in methanol so as to form millimeter-long foils (nanotube paper), consisting of compact arrays of crisscrossing nanotubes. The devices were characterized by electrical resistance measurements and SEM studies.