Figure 1: TEM images of a) as prepared b) ox-MWCNT@40 c) ox-MWCNT@60 d) ox-MWCNT@100. The catalyst and support material which show dark contrast, are thickly covering CNTs for (a) and are seen to reduce with increase in acid oxidation and purification temperature from (b)-(d). The dark spots in image (c) and (d) are mainly due to nanotube endings aligned parallel to the electron beam.