A simple and rapid route for the preparation of iron-based catalyst layers for CVDgrowth of carbon nanotubes is introduced. The catalyst was deposited by a microwave-assisted nonaqueous sol–gel process onto silicon wafers with or without an Al2O3buffer layer and onto colloidal silica spheres. High quality vertically aligned carbon nanotube (VACNT) mats were grown on planar substrates. The versatility of the catalyst preparation is highlighted by the growth of CNTs onto non-planar surfaces such as the silica spheres.