Persistent luminescence of SrAl2O4-based materials decorated with rare-earth oxide nanoparticles

Persistent luminescent materials have attracted great interest due to their ability to store excitation energy and gradually release it after the excitation source is removed, making them attractive for emergency lighting, sensing, and persistent photocatalysis, where reactions continue after irradiation ceases. In this work, SrAl2O₄:Eu²⁺ materials decorated with Dy₂O₃ nanoparticles were synthesized via a microwave-assisted route to evaluate this decoration's influence on structural and optical properties. X-ray diffraction confirmed predominance of the monoclinic phase, space group P2₁, with a minor hexagonal fraction. Photoluminescence revealed a broad orange emission at 613 nm, attributed to the Eu²⁺ 5d to 4f transition, indicating a crystalline environment different from the typical green emission of conventional monoclinic phase. Structural and morphological characterization confirmed formation of the Dy₂O₃/SrAl₂O₄ heterostructure. Photocatalytic activity was evaluated through tetracycline degradation. Results show that Dy₂O₃ decoration effectively tunes SrAl₂O₄ luminescence while creating a heterostructure promising for persistent photocatalysis in environmental remediation.