Multi-walled carbon nanotube growth produced by chemical vapor deposition into self-assembled hexagonally ordered nanoscale pore channels produced by aluminum anodizing and pulse-reverse electrodeposition

Anodic aluminum oxide (AAO) templates for multi-walled carbon nanotube (MWCNT) growth were produced by anodization of aluminum followed by pulse-reverse electrodeposition of cobalt inside the AAO pores. Cobalt functioned as the catalyst for chemical vapor deposition (CVD) growth of fairly well-graphitized MWCNNs initiating inside the majority of the AAO pores and quickly growing beyond the pore confines. A variety of carbon morphologies were found, depending on whether cobalt deposited strictly in the AAO pores or if some pores were over-filled with cobalt. The data presented herein show the importance of particular anodization steps and their effect on catalyst deposition and the resulting carbon morphologies. A novel 25 volt anodizing step was developed to even the electrically insulating barrier layer between the AAO pore bottoms and the metallic aluminum substrate. This enabled the pulsed electrodeposition step to more evenly fill the vast number of AAO pores. (Abstract shortened by UMI.)...