Al2O3 + FeCo and Al2O3 + FeNi coatings for multiwalled carbon nanotubes growth

•Alumina coatings with transition metals were made by sol–gel technique.•Both coatings had the ability to grow CNTs aligned with a uniform size using the technique of water-assisted CVD.•The structural properties of the coatings and CNTs were studied by SEM and powder X-ray and Raman.•Good quality of aligned CNTs obtained for both coatings are reported.

In this work the preparation of growth of aligned multiwall carbon nanotubes (MWCNTs) is presented using FeCo and FeNi alumina-based catalysts. The catalysts were prepared using the sol–gel process and some stainless steel substrates were coated using the dip coating technique. These coatings were used for the MWCNT in a Chemical Vapor Deposition (CVD) reactor. X-ray diffraction (XRD) studies of the coating solutions demonstrate the formation of metallic phases rich in iron in both samples. Raman spectroscopy study depicted the characteristic bands of MWCNT and the scanning electron microscopy (SEM) analysis showing the growth of aligned MWCNTs with a length of about 10 μm and 20 to 80 nm of diameter on both coatings. These results contribute to establishing a new route for the preparation of aligned and high purity MWCNT using catalysts prepared by a very fast and simple way.