Multiwalled carbon nanotube/TiO2 nanocomposite as a highly active photocatalyst for photodegradation of Reactive Black 5 dye

A nanocomposite UV-visible light-responsive multiwalled carbon nanotube (MWCNT)/titanium dioxide (TiO2) nanophotocatalyst was successfully synthesized by a modified sol-gel method using titanium isopropoxide and functionalized MWCNTs as the starting precursors. The photocatalytic activity of the TiO2 and the nanohybrid material was investigated through the photodegradation of Reactive Black 5 dye under ultraviolet light irradiation. X-ray diffraction analysis indicated that anatase phase was obtained for both the pure TiO2 and the MWCNT/TiO2 composite, while Raman spectroscopy confirmed the presence of MWCNTs in the composite. Field emission scanning electron microscopy revealed that TiO2 nanoparticles with an individual diameter of about 10–20 nm were coated on the surface of the MWCNTs. The specific surface areas of the samples were found to be 80 and 181 m2/g for the pure TiO2 and MWCNT/TiO2, respectively. As a result, MWCNT/TiO2 showed better photocatalytic performance than pure TiO2 because the high surface area of MWCNTs enabled them to function as good electron acceptors for the retardation of electron-hole pair recombination.

Graphical AbstractThis paper decribes the feasibility study of a modified sol-gel method for fabrication of TiO2 nanoparticles on the surface of MWCNTs. The hybrid material showed a higher photocatalytic activity than pure TiO2 for the photodegradation of Reactive Black 5 dye in aqueous solution under UV light irradiation.Figure optionsDownload full-size imageDownload as PowerPoint slide