General and facile method to fabricate uniform Y2O3:Ln3+ (Ln3+ = Eu3+, Tb3+) hollow microspheres using polystyrene spheres as templates

Abstract

Well-dispersed, uniform Y₂O₃:Ln³⁺ (Ln³⁺ = Eu³⁺, Tb³⁺) hollow microspheres have been successfully prepared via a urea-assisted homogeneous precipitation method using polystyrene (PS) as templates, followed by a subsequent calcination process. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), photoluminescence (PL) spectra, and cathodoluminescence (CL) spectra were employed to characterize the samples. The results demonstrate that the samples can be well indexed to the pure cubic phase of Y₂O₃. The TEM and SEM images indicate that the shell of the uniform hollow spheres, whose diameter is about 2.1 μm, is composed of many uniform nanoparticles with diameters of around 20 nm. Upon ultraviolet (UV) and low-voltage electron beam excitation, the Y₂O₃:Ln³⁺ (Ln³⁺ = Eu³⁺, Tb³⁺) samples exhibit bright red (Eu³⁺, ⁵D₀ → ⁷F₂), and green (Tb³⁺, ⁵D₄ → ⁷F₅) luminescence. This material may find potential applications in light display systems, optoelectronic devices and drug delivery based on the uniform hollow structure, dimensions, and luminescence properties. Furthermore, this synthesis route may be of great significance in the preparation of other hollow spherical materials.