Visible light photodegradation of phenol on MWNT-TiO 2 composite catalysts prepared by a modified sol–gel method

Abstract

Multi-walled carbon nanotubes (MWNT) and TiO 2 composite catalysts were prepared by a modified sol–gel method. The nanoscaled composite materials were extensively characterized by TG, N 2 adsorption-desorption isotherm, XRD, SEM, EDX, TEM and UV–vis spectra. The photocatalytic degradation of phenol was performed under visible light irradiation on these catalysts. An optimum of synergetic effect on photocatalytic activity was observed for a weight ratio MWNT/TiO 2 equal to 20% with an increase in the first-order rate constant by a factor of 4.1. The synergetic effect, induced by a strong interphase interaction between MWNT and TiO 2, was discussed in terms of different roles played by MWNT in the composite catalysts.