Lanthanide (Ln3+) doped TiO2 supported on Graphene oxide (GO) (Ln3+ =Eu3+ and Sm3+ ions) were prepared via a low cost and facile hydrothermal method. Structural, morphological and optical properties of the un-doped and Ln3+-doped nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX), transmission electron micros...