Synthesis of Gd2O2S : Eu3+ hollow sphere by a hydrothermal method assisting with reduction route

Gd2O2S : Eu3+ hollow spheres were successfully synthesized through a hydrothermal method assisting with reduction route from commercially available Gd2O3, Eu2O3, HNO3, (NH4)(2)SO4 and CO(NH2)(2) (urea) as the starting materials. The assynthesized products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM) and photoluminescence (PL) spectra. The XRD and FT-IR results demonstrate that the precursor has highly crystalline in nature and could be converted into pure Gd2O2S phase at 800 degrees C for 2 hrs in the hybrid atmosphere of flowing argon and hydrogen (90% Ar + 10% H-2). SEM and FE-SEM observations show that the obtained Gd2O2S particles possess hollow sphere structure, which has a typical size of about 10 mu m in diameter and about 1 mu m in shell thickness. PL spectroscopy reveals that the strongest red emission peak is located at 628 nm under 277 nm and 330 nm UV light excitation for the Gd2O2S : Eu3+ (5% mol) hollow spheres, which corresponds to the D-5(0) -> F-7(2) transition of Eu3+ ions. Decay study demonstrates that the D-5(0) -> F-7(2) transition of Eu3+ ions has a single exponential decay behavior. The fitting result shows the lifetime for the D-5(0) -> F-7(2) transition under 277 nm and 330 nm UV light excitation is 0.5692 ms and 0.5435 nm, respectively.