A new method for the preparation of TiO₂ dual-modified by transition metal doping and carbon nanotube (CNT) grafting was proposed. Fe-NiO/TiO₂ was prepared by sol-gel method. Then CNTs were grafted on Fe-NiO/TiO₂ by fluidized bed chemical vapor deposition (FBCVD) method. The dual-modified CNT/Fe-Ni/TiO₂ composite photocatalyst has been characterized by X-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-Vis absorption spectra and photoluminescence spectra. The photocatalytic activities of prepared samples were investigated by the photodegradation of methylene blue (MB). The results show that CNT grafted on TiO₂ had good graphite structure, and small part of TiO₂ was transformed from anatase to rutile during FBCVD process. Double modification of transition metals and CNT can effectively overcome intrinsic defects of TiO₂ in small specific surface area and low quantum efficiency. And the photocatalytic activity has been improved significantly.

Key words: transition metal, carbon nanotube, TiO₂, dual modification, photocatalysis