Synthesis and photoluminescence properties of novel core–shell–shell SiO 2 @CePO 4 :Tb@SiO 2 submicro-spheres

A novel core–shell–shell SiO 2 @CePO 4 :Tb@SiO 2 submicro-sphere was controllably synthesized by a bridging ligand organosilane HOOCC 6 H 4 N(CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 ) 2 (MABA-Si) connecting the silica core and rare earth ions. The as-synthesized samples were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR). It is found that SiO 2 @CePO 4 :Tb@SiO 2 has a ∼25 nm outermost shell, a ∼4 nm intermediate shell, and a ∼200 nm core. SiO 2 @CePO 4 :Tb@SiO 2 exhibits stable photoluminescence properties in aqueous solution: its photoluminescence intensity was unquenched even after 15 days. The core–shell–shell submicro-spheres were found to have better photoluminescence than the core–shell submicro-spheres because the SiO 2 shell protected the phosphor materials and then improved its photoluminescence intensity and biocompatibility. A formation mechanism of the core–shell–shell SiO 2 @CePO 4 :Tb@SiO 2 submicro-spheres was proposed. Thus, the low-cost preparation of the core–shell–shell SiO 2 @CePO 4 :Tb@SiO 2 submicro-spheres could be rationally achieved using SiO 2 .