In this study, synthesis of bimetallic (Co, Mn, and Ni) complexes of salicylic acid (L1) and 1,2 dihydroxybenzene (L2) based on titanium(IV) were investigated, then the samples were decomposed by thermal method to obtain MxTiyOz nanoparticles (M = Ni, Co, and Mn). The samples in complexes mode were analyzed by UV–Vis (200–800 nm), FT-IR (4000–400 Cm−1), CHN analysis and the structure of the bimetallic compounds also were investigated by the Quantum-chemical modelling. In addition, the samples in nanoparticles mode were studied by thermal analysis (to obtain DTA curves), XRD, FESEM image and EDX analyzing. BET surface analysis was carried out to analyze active surface, pore diameter and porosity of the MxTiyOz nanoparticles. Based on the results, obtained samples as catalysts were able to absorb not just UV but also visible light. Catalysts were able to degrade bromophenol blue as a harmful organic substance under UV and visible lights, although, this ability was more significant when the samples were used under visible light. © 2018