The bandgap of mesoporous nanocrystalline TiO2 was modified by wet impregnation with Li, Mg, Pd, and Sr metal ion salt solutions. X-ray Diffraction (XRD), UV-Vis Diffuse Reflectance Spectrophotometer (DRS), Scanning Electron Microscope (SEM), and BET techniques were used for the characterization of TiO2 samples. DRS data showed highest blue shift of 21 nm and lowest of 9 nm for Pd and Li ion impregnated TiO2 respectively. Ion impregnated samples were used as photocatalysts to study the effect of change in bandgap on the photodegradation activity. Nitrobenzene (NB) and acetophenone (AP) in aqueous solutions under ultraviolet light irradiation were used for studying photocatalytic degradation. (C) 2011 Elsevier B.V. All rights reserved.