Morphology control and synthesis of afterglow materials with a SrAl2O4 framework synthesized by Surfactant-Template and hydrothermal methods

Highlights: • Afterglow materials have long emission lifetimes up to seconds to minutes. • We synthesize Eu²⁺, Dy³⁺@SrAl₂O₄, where emitting agents are co-doped in SrAl₂O_4. • The liquid-state reaction plays a crucial role in the synthesis of materials. • Synthesis with a surfactant-template method yields product morphologies in 40–80 nm. • The hydrothermal method that produces morphologies up to approximately 2–3 μm. Afterglow materials, which are also known as persistent emitters, have a long emission lifetime that varies from seconds to tens of minutes. These materials have shown potential applications in photoenergy conservation devices such as evacuation signage and emitting lines in a motorway surface. In this study, we synthesized afterglow materials, Eu²⁺, Dy³⁺@SrAl₂O₄, wherein the emitting agents (Eu²⁺ and Dy³⁺) are co-doped in a SrAl₂O₄ framework, which was confirmed by X-ray diffraction. The liquid-state reaction process plays a crucial role in the synthesis of materials. When the surfactant-template method is used for synthesis, reverse micelles, which control the morphology of afterglow product, hold the raw reactant materials, thereby yielding characteristic morphologies of approximately 40–80 nm. The reverse micelles have been detected by small-angle X-ray scattering in this study. In contrast, the hydrothermal method produces morphologies up to approximately 2–3 μm. Results suggest that both the synthetic routes yield similar emission spectra and mean afterglow time of ~ 10 s.