Synthesis and characterization of TiO2 coated multiwalled carbon nanotubes using a sol gel method

A considerable improvement in the quality of TiO2 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 synthesis of the TiO2 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 TiO2 coated MWNTs obtained by sol-gel. TEM results showed that the MWNTs were fully and homogeneously coated with TiO2 while SEM coupled with EDX confirmed the presence of a thick layer of TiO2 coating the MWNTs. XRD and Raman spectroscopy results revealed that the crystalline structure of TiO2 on the surface of MWNTs was anatase.