Hydrothermal synthesis of single-walled carbon nanotube–TiO2 hybrid and its photocatalytic activity

A single-walled carbon nanotube (SWCNT)–TiO2 hybrid was prepared hydrothermally by direct growth of TiO2 nanoparticles on the surface of functionalized SWCNTs to develop highly efficient photocatalysts. The SWCNT–TiO2 hybrid was characterized by X-ray diffraction, electron microscopy, N2-adsorption analysis, FT-IR, Raman, and UV–vis spectroscopy. The photocatalytic activity of the SWCNT–TiO2 hybrid was examined by the photocatalytic degradation of pirimicarb. Although the SWCNT–TiO2 hybrid exhibits no visible-light-induced activity, the photocatalytic degradation efficiency of pirimicarb over TiO2 can be increased significantly with the introduction of SWCNTs (2–3 times) because SWCNTs can act as electron conductors that hinder the recombination of photo-generated electrons and holes. Compared with a multi-walled carbon nanotube–TiO2 hybrid, it can be found that the electronic configurations of carbon nanotubes significantly affect the photocatalytic activity of carbon nanotube–TiO2 hybrid. Metal-typed SWCNTs act more as an electrical conductor than a photosensitizer, which efficiently suppress charge recombination, improve interfacial charge transfer, and improve the photoactivity.