“…The peak at 1071 cm -1 is related to the Si-O-Si bond, which confirms the success of the carbon nanotubes coating with silica [72]. The functionalization of carbon nanotubes with amine is also proved with the peak at 3394 cm -1 that corresponds to NH2 [73]. The peak at 2922 cm -1 belongs to the -CH2 group of CTAB surfactant, indicating that the surfactant removal was not completed [58].…”