Surface modification of amorphous carbon nanotubes with copper phthalocyanine leading to enhanced field emission

Amorphous carbon nanotubes (ACNTs) were synthesized by following a simple chemical route with ammonium chloride and ferrocene taken as starting materials and heating at 250 degrees C under an open atmosphere. The as-prepared samples were oxidized and chemically activated by simple acid treatment and further functionalized by copper phthalocyanine (CuPc). The attachment of CuPc at the walls of the nanotubes was investigated by Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission and scanning electron microscopy. The field emission properties of ACNTs was found to be greatly enhanced after coating them with CuPc. The effects of inter-electrode distance on the field emission properties of the functionalized samples were also studied.