Uniform hollow TiO2:Sm3 + spheres: Solvothermal synthesis and luminescence properties

Sm-doped hollow titania microspheres were fabricated by a simple solvothermal method using carbon spheres as hard template. The samples were characterized by X-ray diffraction (XRD), fourier transform infrared spectrum (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) and photoluminescence spectrum. In TEM images, hollow spheres with uniform morphology can be clearly observed. XRD results confirm that the hollow TiO2 spheres are anatase phase. The photoluminescence (PL) spectra of Sm-doped hollow TiO2 microspheres are dominated by red-emission around 612 nm due to intra-atomic 4f → 4f (4G5/2 → 6H7/2) transition of Sm3 +. The effect of doping concentrations of Sm3 + on the luminescence was investigated. The results show that the luminescence of TiO2:Sm3 + hollow microspheres has the strongest emission intensity when the ratio of Sm3 + is 2 mol%.