In this study, highly active titanium dioxide modified by niobium oxide (Nb2O5), polymer (PANI) and reduced graphene oxide (RGO) were successfully prepared. The morphology, structure, surface area and light absorption properties of the present nanocomposites for removal of methylene blue (MB) and methyl orange (MO) were investigated and compared with those of TiO2/Nb2O5 and TiO2 nanoparticles. The characterization techniques such as XRD, FT-IR, UV-vis, SEM, EDX, BET and TEM were employed in order to identify the nanocomposites. Also, photocatalytic properties of TiO2/Nb2O5/PANI and TiO2/Nb2O5/RGO nanocomposites under visible light irradiation were studied. In this way, the obtained results were compared to each other and also compared to TiO2/Nb2O5 and TiO2 nanoparticles. In this context, the chemical oxygen demand (COD) removal follows the photodegradation in observed performance. The results indicate that reduced TiO2/Nb2O5 nanocomposite is effectively modified by graphene oxide to give TiO2/Nb2O5/RGO composite. The TiO2/Nb2O5/RGO exhibits significantly higher photocatalytic activity in degradation of organic dyes under visible light rather than that of TiO2/Nb2O5/PANI, TiO2/Nb2O5 and pure TiO2.