Mesoporous nanocrystalline metal oxides such as TiO2, SnO2, and TiO2-SnO2 composites form a new class of mesoporous inorganic solids, which exhibit excellent structural, textural, optical, and photocatalytic properties. Furthermore, they also possess a large number of surface-exposed catalytic active sites in addition to their intrinsic flexible diffusion characteristics. In this investigation, we report the photocatalytic activity of high-quality mesoporous TiO2, SnO2, and TiO2-SnO2 composites. All the catalysts were tested for photocatalytic degradation of 4-chlorophenol under a solar simulator. The reaction results indicate that the anatase-phase mesoporous Ti0·9Sn0·1O2 exhibits enhanced activity as compared with the commercial TiO2 (P-25). © 2019 Elsevier Ltd