A novel synthetic route towards monodisperse LaOF:Ln³⁺ (Ln = Eu, Tb) hollow spheres with multicolor luminescence properties

Abstract

In this study, monodisperse and uniform LaOF hollow spheres were successfully synthesized through a novel facile synthetic route employing a La(OH)CO3 sphere as a sacrificial template followed by a subsequent calcination process. The structure, morphology, formation process, and luminescence properties were well investigated using various techniques. The possible formation mechanism of evolution from the La(OH)CO3 spheres to the LaCO3F precursor, and to the final LaOF hollow spheres can be attributed to the Kirkendall effect and the decomposition of the LaCO3F precursor. Under ultraviolet excitation, the LaOF:Ln(3+) (Ln = Eu,Tb) hollow spheres show their characteristic f-f emissions and exhibit red, green emissions, respectively. Moreover, by codoping the Tb(3+) and Eu(3+) ions into the LaOF host and tuning their relative concentration ratio, multicolor tunable emissions are obtained due to the efficient energy transfer from Tb(3+) to Eu(3+) at 378 nm excitation. This material may find potential application in color display fields.

Simultaneous Dual-mode Emission and Tunable Multicolor in the Time Domain from Lanthanide-doped Core-shell Microcrystals

“…The corresponding emission spectra of NaYF 4 :Yb/Er@NaYF 4 :Ce/Tb/Eu microrods are displayed in Figure 3b when excited at 252 nm directly. The emission spectra are recorded by characteristic transition for both Tb 3+ and Eu 3+ in the visible region [25,26,27,28]. The emission peaks at 489, 544, 584 and 620 nm due to electronic transition from Tb 3+ ions ( 5 D 4 → 7 F J (J = 6, 5, 4, and 3)) are observed.…”

“…Hexagonal-phase NaYF 4 is not only considered as excellent UC host materials, but also offers efficient DS emission of Ln 3+ ions such as Tb 3+ and Eu 3+ , hence generating bright green and red DS emission in the visible region [25,26]. Thus, recently, the Tb 3+ and Eu 3+ co-doping in host has aroused many researchers’ interest due to tunable DS emission colors [19,27,28,29]. However, in these literatures, quite little attention has been paid to Tb-Eu co-doped core-shell-structured nanoparticles for dual-mode emission.…”

Template-free hydrothermal synthesis of Gd2O2SO4:Eu3+ hollow spheres based on urea-ammonium sulfate (UAS) system

“…Template-free strategies mainly rely on various well-known phenomena such as Ostwald ripening [13], Kirkendall effect [14] and chemically induced self-transformation [15], which all have been widely employed for fabricating hollow spheres due to its simple and economical characteristics.…”

Assembly of 1D coaxial nanoribbons into 2D multicolor luminescence array membrane endowed with tunable anisotropic electrical conductivity and magnetism via electrospinning

“…18,19 By doping Eu 3+ and Tb 3+ ions, materials can emit multicolor light, which have wide and important applications in computer displays, lighting and medical equipment. For example, Li et al 20,21 prepared well dened LaOF crystals and LaOF hollow spheres. By codoping Tb 3+ and Eu 3+ ions into the LaOF host and modulating the doping concentration of the Eu 3+ ions, tunable multicolor emissions were obtained under 379 nm irradiation.…”