Mesoporous TiO2 was synthesized using triblock copolymer as the structure directing template in ethanol/water, isopropanol/water or 1-butanol/water medium by sol-gel method. The presence of intense peak at low angle in the XRD patterns confirmed the orderly arrangement of mesopores in the material. Among the three different alcohols, ethanol had influenced better in controlling the particle size than others. The enhanced specific surface area also revealed the formation of mesopores. Aggregates of particles were clearly seen in the TEM images and the size of the particles was approximately 10 nm. The photocatalytic activity of mesoporous TiO2 was evaluated using aqueous alachlor as a model pollutant. The activity of mesoporous TiO2 synthesized in ethanol/water mole ratio of 50 was higher than other mesoporous TiO2 and commercial TiO2 (Degussa P-25). The transport of excited electrons from one particle to its neighboring nanoparticles of mesoporous TiO2 is suggested to be the cause for enhanced photocatalytic activity. (C) 2010 Elsevier B.V. All rights reserved.