Two-step synthesis of hole structure bastnasite (RECO3F RE = Ce, La, Pr, Nd) sub-microcrystals with tunable luminescence properties

Abstract

A two-step synthetic route using RE(OH)CO₃ colloid spheres as the sacrificial template was designed to prepare monodisperse, pure bastnasite (RECO₃F: RE = Ce, La, Pr, Nd) with a hole structure for the first time. A variety of morphologies, including jujube core-like, stacked nanoblocks, and stacked nanosheets were obtained through changing the ratio of reactants. The phase, structure, shapes, and photoluminescence properties of samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The CeCO₃F:Ln³⁺ (Ln = Tb, Eu, Dy) phosphors give green, yellow and blue emission, respectively, due to the f–f transitions of Ln³⁺ ions. Furthermore, the energy transfer from Ce³⁺ to Dy³⁺ and Tb³⁺ was described in detail.