Synthesis and luminescent characterization of Y2O2S: Eu3+, Mg2+, Ti4+ nanotubes

We report an effective method to synthesize a red long-lasting phosphorescent material, Y2O2S: Eu3+, Mg2+, Ti4+ nanotubes. Y(OH)3 nanotubes were first synthesized by a convenient hydrothermal method to serve as the precursor. Y2O2S: Eu3+, Mg2+, Ti4+ powders were obtained with high yield and purity by calcinating the precursor in CS2 atmosphere. The morphology and optical properties of the composites were characterized. XRD investigation showed a pure phase of Y2O2S. SEM and TEM observation revealed that the phosphors with diameters of 100–200 nm and lengths of 1–3 μm inherited the tube-like shape from the precursor after being calcinated in CS2 atmosphere. From the spectrum, the main emission peaks are ascribed to Eu3+ ions transition from 5DJ (J=0, 1, 2) to 7FJ (J=0, 1, 2, 3, 4). After irradiation by 265 or 325 nm, the phosphor emitted red color long-lasting phosphorescence. It was considered that the red-emitting long-lasting phosphorescence was due to the persistent energy transfer from the traps to the Ti4+ and Mg2+ ions.