title: Synthesis of Y2O2S:Eu3+, Mg2+, Ti4+hollow microspheres via homogeneous precipitation route.
abstract: A phosphorescent material in the form of Y2O2S:Eu3+, Mg2+, Ti4+hollow microspheres was prepared by homogeneous precipitation using monodispersed carbon spheres as hard templates. Y2O3:Eu3+hollow microspheres were first synthesized to serve as the precursor. Y2O2S:Eu3+, Mg2+, Ti4+powders were obtained by calcinating the precursor in a CS2atmosphere. The crystal structure, morphology and optical properties of the composites were characterized. X-ray diffraction measurements confirmed the purity of the Y2O2S phase. Electron microscopy observations revealed that the Y2O2S:Eu3+, Mg2+, Ti4+particles inherited the hollow spherical shape from the precursor after being calcined in a CS2atmosphere and that they had a diameter of 350-450 nm and a wall thickness of about 50-80 nm. After ultraviolet radiation at 265 or 325 nm for 5 min, the particles emitted strong red long-lifetime phosphorescence originating from Eu3+ions. This phosphorescence is associated with the trapping of charge carriers by Ti4+and Mg2+ions.
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Ai
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Ying-Liang
authors.initials: YL
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Xiao
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Hou-Jin
authors.initials: HJ
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Meng
keywords: hollow microsphere; homogeneous precipitation method; luminescence; yttrium oxysulfide