High density carbon nanotube growth using a plasma pretreated catalyst

We have developed a direct current plasma pretreatment of the Fe catalyst to increase the area density of vertically-aligned carbon nanotube forests. The carbon wall density of the double- and multi-walled nanotubes reaches 4.8 x 10(12) cm(-2), with a 40% volume occupancy and a mass density. of similar to 0.4 g cm(-3). The plasma pretreatment works by reducing the sintering of the catalyst nanoparticles during growth. This treatment increases the forest density by 8 times compared to the standard growth conditions. (C) 2012 Elsevier Ltd. All rights reserved.