Figure 2

TEM images, SAED patterns, and EDXS analytical histograms. TEM images of the individual CNNCs prepared at the CH₄/N₂ feeding gas ratios of (a) 1/20 and (f) 1/5, SAED patterns taken from the black areas of the central pipes (b and g) and the lateral gray areas (d and i), and EDXS analytical histograms (c, e, h, and j) at the locations corresponding to subgraphs (b, d, g, and i), respectively.