Effect of buffer layer deposition on diameter and alignment of carbon nanotubes in water-assisted chemical vapor deposition

► Deposition rate of the buffer layer governs the substrate topography. ► Buffer layer topography influences the catalyst rearrangement. ► A higher deposition rate makes the substrate rougher. ► Rougher substrate grows the aligned, small diameter CNTs with greater height. ► Slow deposition rate samples show the opposite trend.