Synthesis of activated carbon-surrounded and carbon-doped anatase TiO2 nanocomposites

A specially designed photocatalytic structure, i.e., carbon-doped anatase-TiO2 (A-TiO2-xCx) 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-TiO2 grain growth and aggregation during the carbonization step, reducing the average grain size of the A-TiO2 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-TiO2 clusters during the carbonization step. The porous AC of high specific surface area within the novel A-TiO2-xCx-AC nanocomposites shows excellent adsorption ability for concentrating organics at the vicinity of A-TiO2-xCx nanocrystallites. Unlike the A-TiO2 crystals, the synergy between C-doped A-TiO2 and AC definitely promotes the visible-light photo-induced degradation efficiency of organics.