Preparation of multi-walled carbon nanotube supported TiO 2 and its photocatalytic activity in the reduction of CO 2 with H 2O

Abstract

Multi-walled carbon nanotube (MWCNT) supported TiO 2 composite catalysts were prepared by sol–gel and hydrothermal methods. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy and N 2-adsorption analysis were carried out to characterize the composite catalysts. In using the sol–gel method, the MWCNTs were coated with anatase TiO 2 nanoparticles, and by the hydrothermal method, rutile TiO 2 nanorods were uniformly deposited on the MWCNTs. The photocatalytic activities of the composite catalysts were evaluated by the reduction of CO 2 with H 2O. The results indicate that the addition of an appropriate amount of MWCNTs as supports for TiO 2 could remarkably improve the efficiency of the photocatalytic reaction. The composite catalysts prepared by the sol–gel method lead to the main formation of C 2H 5OH, while HCOOH is found to be the major product on the sample prepared by the hydrothermal method.