Facile Template-Free Fabrication of the hollow sea cucumber-like TbF₃ and luminescent properties

Graphical abstract: Hollow sea cucumber-like TbF₃ has been prepared via a facile hydrothermal route. The possible growth mechanism and the luminescent properties of the as-prepared sample have been discussed. - Highlights: • TbF3 particles were prepared by a facile hydrothermal route. • TbF3 product show strong green emission. • This method may be more widely applicable in the design of other rare-earth compounds. - Abstract: Hollow sea cucumber-like TbF₃ was successfully fabricated by a self-assembled hydrothermal method. The crystal structure, morphology and photoluminescence properties of the as-prepared TbF₃ crystals were investigated. The results revealed that the as-prepared TbF₃ sample has orthorhombic structure and composed of monodispersed 3D hollow sea cucumber-like particles. The possible formation mechanism for sea cucumber-like TbF₃ is presented in detail. Additionally, the as-prepared sample possesses property of down-conversion photoluminescence. The excitation spectrum of TbF₃ sample was obtained by monitoring the emission of Tb³⁺ at 545 nm was composed of the characteristics f–f transition lines within the Tb³⁺ 4f⁸ configuration. Under the UV light irradiation, the emission spectrum exhibited four obvious lines centered at 491, 545, 588, and 620 nm, which was corresponding to the ⁵D₄ → ⁷F_J (J = 6, 5, 4, 3) transitions of the Tb³⁺ ions in the TbF₃ nanoparticles