Hollow mesoporous Gd2O3:Eu3+ spheres with enhanced luminescence and their drug releasing behavior

Abstract

Hollow mesoporous Gd₂O₃:Eu³⁺ nanospheres were successfully synthesized by using carboxyl-capped polystyrene (CCPS) nanospheres as sacrificed templates, which turn out to be ideal templates to fabricate Gd₂O₃:Eu³⁺ nanospheres due to the carboxyl of polystyrene being affined to REE (rare earth element). The X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), photoluminescence (PL), and UV-vis absorption spectral were used to characterize as-obtained products. The mesoporous structure is revealed by TEM images as well as N₂ adsorption–desorption isotherm. The samples are composed of hollow mesoporous Gd₂O₃:Eu³⁺ nanospheres with a mean particle size of about 276 nm. It is also found that hollow mesoporous Gd₂O₃:Eu³⁺ nanospheres exhibit strong red light emission under ultraviolet excitation. Significantly, the strongly luminescent property of the hollow mesoporous spheres could be better tracked as drug delivery host carriers, the IBU–Gd₂O₃ systems displayed a fast release in the initial 10 h, and a sustained release property with durable release rate.