A series of multi-walled carbon nanotube/titanium dioxide (MWCNT/TiO2) composites were prepared by the sol-gel method. The structure, composition and morphology of the as-prepared samples were characterized. Taking methyl orange (MO) as the simulate organic pollutant, the influences of various factors on the decontamination of the samples and its reusing performance were researched. The results showed that the decontamination activity of the MWCNT/TiO2 composite with mass ratio of MWCNT to TiO2 equal to 1/2 and 450 degrees C of sintering was optimum in the MO solution of pH = 2, and the composite has good performance for repeated use. What is more, the possible mechanism of decontamination was studied further. (C) 2014 Elsevier B.V. All rights reserved.