A synergy effect by carbon and anatase in the mesoporous C-TiO2 nanocomposites is reported here on the degradation of dye in contaminated water. The as-formed mesoporous C-TiO2 composites have ordered 2D hexagonal mesostructure, high surface area (384 m(2)/g), uniform and large mesopores (4.5 nm), large pore volume (0.31 cm(3)/g), titania nanoparticles confined inside carbon frameworks, tunable TiO2 contents (40-87 wt%), and dopant of element carbon into anatase lattice. The large mesopore space of carbon offers high capacity for the adsorption of dyes from water. Well-dispersed and carbon-doped anatase TiO2 nanoparticles are active for photocatalysis especially in visible light region. Once the dyes are involved inside mesopores by adsorption, they are easily accessible to anatase particles through the common interface between the two, and immediately fully oxidized. The immobilization of anatase particles in the carbon framework greatly improves the stability during its usage. The mesoporous C-TiO2 nanocomposite catalysts can be reused more than 20 times without obvious loss both in anatase content and processing ability of contaminated water. (C) 2013 Elsevier B.V. All rights reserved.