Synthesis and characterization of Y2O2S:Eu3+, Mg2+, Ti4+ nanotubes via hydrothermal method

We reported an effective method to synthesize Y2O2S:Eu3+, Mg2+, Ti4+ nanotubes. The Y(OH)3 doped with Eu3+, Mg2+ and Ti4+ ions by hydrothermal method serves as the precursor. The red long-lasting phosphor Y2O2S:Eu3+, Mg2+, Ti4+ nanotubes were obtained by means of calcinating the precursor in CS2 atmosphere. The samples were examined using X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) and illuminometer. The results of XRD revealed that the phase of sample was Y2O2S when the sulfuretted temperature reached 750 °C. SEM observations showed that the phosphors with diameters of 200–400 nm and lengths of 2–3 μm inherited the tube-like shape from the precursor after calcination in CS2 atmosphere. Under 325 nm UV excitation, the samples exhibited the strongest red emission at 625 nm, which corresponded to transition from 5D0 to 7F2 level of Eu3+ ion. After irradiation with 365 nm UV (Ultraviolet) radiation for 10 min, the nanotubes emitted red long-lasting phosphorescence which could last for about 870 s (image1 mcd/m2). And the red-emitting long-lasting phosphorescence was attributed to the persistent energy transfer from the traps to the Ti4+ and Mg2+ ions.