Monochiral tubular graphite cones formed by radial layer-by-layer growth

Multiwalled carbon nanotubes in the form of tubular graphitic cones (TGC) are grown at high yield. Structure analysis reveals that chirality of the multiple walls in a TGC are nearly identical to each other and preferentially zigzag. The formation of such TGCs is explained by two separate processes along radial and axial directions, respectively. The root-based radial growth is via a layer-by-layer mode that controls the chirality of tubes. The axial growth extends the tubules with nearly identical chiral angles. Total energy calculations indicate that the inner tube with near zigzag chirality is favored to template the growth of monochiral multiwalled structures, in good agreement with experiments.