The comparative microstructures and photonic effects of CNT/TiO(2) composites which were derived from pre-oxidized carbon nanotubes and different titanium alkoxide precursors (titanium (IV) n-butoxide (TNB), titanium(W) isopropoxide (TIP) and titanium(IV) propoxide (TPP)) by a sol-gel method. The composites were characterized by theirBrauer-Emett-Teller surface areas, transmission electron microscopy, X-ray diffraction, and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation was tested using methylene blue (MB) in an aqueous solution. The CNT/TiO(2) composites derived from the TIP precursor only existed in an anatase state with a very strong intensity, while the CNT/TiO(2) composites derived from TIP and TPP precursors included a mixed structure of anatase and rutile. The TiO(2) particles were embedded into the tubes of CNTs for the CNT/TiO(2) composites derived from the precursors with TNB and TIP, while for the CNT/TiO(2) composites from TPP the TiO(2) particles were only distributed outside the surfaces of the CNTs and partially aggregated. The CNT/TiO(2) composites derived from TPP have a higher degradation effect on the MB solution more than that of TNB and TIP as titania precursors. A mechanism of TiO(2) particles dispersing inside or outside of the CNT is proposed.

Keywords: CNT; TiO(2); titania precursor; comparative microstructure; photocatalytic effect