Application of the composite of TiO(2) nanoparticles and carbon nanotubes to the photo-reduction of Cr(VI) in water

The composite of carboxyl-modified multi-walled carbon nanotubes (MWNT-COOH) and TiO(2) nanoparticles was prepared in a solvothermal process. The x-ray diffraction (XRD), transmission electron microscope (TEM) and UV-vis spectrum were used to characterize the products. The results showed that the MWNT-COOH was dispersed uniformly in the composite and coated with TiO(2) nanoparticles. The photo-reduction of Cr(VI) to Cr(III) in water catalyzed by the composite was investigated at room temperature. The photocatalytic activity of the composite markedly increased by a factor of approximately 2.2 in comparison with pure TiO(2) (P25). Furthermore, the mechanism of the photocatalytic activity enhancement of the MWNT-COOH/TiO(2) nanoparticles composite for the photo-reduction of Cr(VI) was discussed.