Direct Route to Grow CNTs by Micro-Electrodischarge Machining without Catalyst in Open Air

Abstract

In the present study, carbon nanotubes (CNTs) were fabricated by a single pulse discharge using a micro-electrodischarge machining (MEDM) system in open air without a catalyst. The MEDM system could manipulate the discharge location, peak current, and pulse duration. By controlling the discharge points, patterning was made feasible. Controlling the peak current (3, 4, and 5 A) and pulse duration (fixed at 1,200 ms) made it possible to optimize the energy input to synthesize CNTs. Observations made using a field-emission scanning electron microscope and transmission electron microscope showed that multiwalled CNTs were formed within the discharge points. The CNTs grown at a peak current of 4 A exhibited a sharp end and a slight 10°bend.

Keywords:

• Carbon nanotubes
• Catalyst
• Electrical discharge machining
• Nanotechnology
• Open air