The photocatalytic activity of well-fabricated, economical SnO2/TiO2 nanocomposite synthesized via hydrothermal route was validated using the (NH3-trz)[Fe(dipic)2] complex under ultra-violet illumination. The structural features of (NH3-trz)[Fe(dipic)2] complex was explored in detail. The catalysts were systematically examined with XRD, SEM, FT-IR UV-vis, PL, micro-Raman, VSM, AFM, HRTEM. The photoreactivity of the model compound (NH3-trz)[Fe(dipic)2] in water/binary solvent systems was investigated. The rate of photoreaction (k) of nanocomposite (0.1432 sec -1) is higher than the SnO2 (0.0373 sec-1) and TiO2 (0.1422 sec-1) in H2O:PriOH (70:30%) than the rest of the solvents system. The pathways, mechanistic feature of accumulated reactive species on nanocomposite to induce adherent [Fe(dipic)2]- anion and photo-reductive products were studied. The generation of hydroxyl radical on the surface of each catalyst can be identified as 7-hydroxycoumarin and discussed.