Catalyst free growth of a carbon nanotube–alumina composite structure

Aligned arrays of multiwall carbon tubes (CNTs) were prepared within cylindrical pores of compact porous anodic aluminum oxide (PAOX) by a non-catalytic chemical vapor deposition (CVD) method. Optimum CNT synthesis conditions were determined for two crucial reaction parameters, e.g. the precursor gas flow and the reaction time for a given fixed reaction temperature. Gas phase oxidation followed by a wet chemical dissolution allows selective removal of carbon by-products from the surface of the CNT/PAOX composite without destroying its structure. The developed procedure opens up the way to obtain CNT/alumina composites with open, 2D arranged pores by a selective gas phase and solution chemical etching technique.