Additionally, a low intensity peak centered at 285.9 eV was assigned to C-O 1,39 bonds. In contrast, the CNT membrane after CVD shows four distinct peaks (Fig. ). Major peaks centered at 284.6 eV, 283.3 eV and 282.4 eV were assigned to sp 2 hybridized C-C bonds, C-B 40 bonds (where sp 2 hybridized carbon atoms are bonded to the equatorial B atoms in the icosahedra), and C atoms bonded to the sp hybridized B atoms in the C-B-C 40 chains, respectively. Satellite peaks centered at 286 eV and 289 eV were assigned to C-O 1 , and O-C=O 39 bonds, respectively. A shoulder can be observed below 284 eV, which arises from the deposited film where C was bonded to less electronegative B atoms. Further, broadening of the major peak centered at 284.5 eV indicates contribution from both the deposited film and the CNT underneath. We suggest that the differential charging of the membrane surfaces before and after CVD contributed to the broadening of the FWHM of sp 2 hybridized C-C bond signals from 0.85 eV to 1.20 eV. The B 1s core level spectra shows three peak positions (Fig. ).