A considerable improvement in the quality of TiO 2 coatings on multiwalled carbon nanotubes (MWNTs) was obtained by introducing a three-step purification and functionalization process which combines oxidation in air followed by sulfuric acid refluxes and reoxidation in air before synmesis of the TiO 2 coating by the sol-gel method. A range of techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-rays (EDX), X-ray diffraction (XRD), Raman spectroscopy, and thermal gravimetric analysis (TGA) were applied to characterize TiO 2 coated MWNTs obtained by sol-gel. TEM results showed that the MWNTs were fully and homogeneously coated wim TiO 2 while SEM coupled with EDX confirmed me presence of a thick layer of TiO 2 coating the MWNTs. XRD and Raman spectroscopy results revealed that the crystalline structure of TiO 2 on the surface of MWNTs was anatase.
Sharif Zein, S. H., & Boccaccini, A. R. (2008). Synthesis and characterization of TiO2 coated multiwalled carbon nanotubes using a sol gel method. Industrial & engineering chemistry research, 47(17), 6598-6606. https://doi.org/10.1021/ie701770q