Improved field emission from amorphous carbon nanotubes by surface functionalization with stearic acid

Amorphous carbon nanotubes (a-CNTs) were synthesized by a simple process using ammonium chloride and ferrocene at a low temperature (∼250 °C) in open atmosphere. The as-prepared samples were oxidized by a simple acid treatment and further functionalized with stearic acid. For the confirmation of oxidation and functionalization, the pristine and the modified a-CNTs were characterized by Fourier transformed infrared spectroscopy, transmission and scanning electron microscopy. The as-prepared samples showed good field emission (FE) and the FE characteristics were significantly improved for the stearic acid functionalized samples compared to the pristine sample. The effects of inter-electrode distance on the FE properties of the functionalized samples were also studied.