Synthesis of activated carbon-surrounded and carbon-doped anatase TiO2 nanocompositesElectronic supplementary information (ESI) available: The XRD pattern of the control sample, HRTEM image for thick AC-coating, UV-vis spectra for MB degradation, XPS spectra and SEM images of all samples are available. See DOI: 10.1039/c0jm00286k

A specially designed photocatalytic structure, i.e. , carbon-doped anatase-TiO 2 (A-TiO 2− x C x ) nanocrystallites surrounded with activated carbon (AC), is synthesized by a simple one-step carbonization of a self-assembled matrix consisting of titanium tetra-isopropoxide (TTIP) and triblock copolymer. The self-assembled copolymer homogeneously disperses TTIP and possesses a steric inhibition of A-TiO 2 grain growth and aggregation during the carbonization step, reducing the average grain size of the A-TiO 2 nanocrystallites. An additional merit of this simple process, the facile formation of visible-light-driven photocatalysts through carbon-doping, is attributable to the retention of few-nanometre-sized A-TiO 2 clusters during the carbonization step. The porous AC of high specific surface area within the novel A-TiO 2− x C x -AC nanocomposites shows excellent adsorption ability for concentrating organics at the vicinity of A-TiO 2− x C x nanocrystallites. Unlike the A-TiO 2 crystals, the synergy between C-doped A-TiO 2 and AC definitely promotes the visible-light photo-induced degradation efficiency of organics. A specially designed photocatalytic structure of carbon-doped anatase-TiO 2 nanocrystallites surrounded with activated carbon is synthesized by a simple one-step carbonization of a self-assembled matrix of titanium tetra-isopropoxide and a triblock copolymer. The photo-induced degradation efficiency of organics under the illumination of visible-light is improved.