Transition metal and metal ions such as Fe, Cu, Ag, Au and Cr dispersion into TiO2 matrix was done by impregnation and NaBH4 reduction in aqueous solution. These metal-TiO2 composites were characterized by XRD, SEM, TEM, EDS, diffuse reflectance spectral analysis and magnetic susceptibility and are tested for iodine formation. Metal loading results in red shift of absorption band along with characteristic surface plasmon band for Ag (similar to 460 nm) and Au (similar to 570 nm). TEM images reveal the fairly uniform metal deposition with size range of 6-15 nm depending upon the nature of metal. High concentration of Fe3+ loading led to agglomeration of TiO2 particles due to high magnetic properties. X-ray diffraction shows the shift of 2 theta angle of (1 0 0), (1 0 1) and (2 0 0) lattice planes of TiO2 to lower value and increase in activity is attributed to change in the lattice parameters and cell volume on high Fe3+ concentration. The co-catalysis of 10 wt.% Fe3+ and Fe-0 makes a large difference in iodine formation rate. Metal loading significantly enhance the photooxidation of iodide ion under UV light in order Fe3+ > Cr6+ > Ag > Au > Cu depending upon their oxidation state, nature, electron capturing tendency, work function, etc. (C) 2013 Elsevier B.V. All rights reserved.