Carbon nanotube with a graphitic outer layer: process and application

A method for manufacturing a carbon nanotube device consisting of a carbon nanotube core having an integrally attached outer graphitic layer comprising the steps of:

• a) preparing a transition metal catalyst on a selected substrate;
• b) placing the transition metal catalyst and substrate of step (a) in a reaction vessel;
• c) purging the reaction vessel of step (b) by heating said vessel to a temperature between 500° C. and 750° C. while introducing a gaseous mixture of hydrogen and an inert gas;
• d) growing a carbon nanotube core by changing the gaseous mixture of step (c) to a stream consisting of approximately 10% carbon-containing gas and approximately 90% inert gas, while increasing the temperature of the reaction vessel to a range between 750° C. and 900° C.;
• e) growing an integrally attached graphitic outer layer on the carbon nanotube core of step (d) by changing the reaction parameters to promote the distinct formation of carbon material selected from the group consisting of amorphous carbon, graphitic carbon and mixtures thereof;
• f) removing the carbon nanotube with graphitic outer layer of step (e) from the reaction vessel;
• and
• g) mechanically breaking away a portion of the graphitic outer layer to leave the carbon nanotube core partially exposed.