Stable, Full‐Color, Long‐Lasting Aqueous Room‐Temperature Phosphorescent Materials

Ultralong room-temperature phosphorescent (URTP) materials have garnered significant attention in anti-counterfeiting, optoelectronic displays, and bio-imaging due to their unique optical properties. However, most URTP materials exhibit weak emission or are quenched in aqueous solutions. This study proposes a simple and effective strategy for preparing full-color aqueous URTP materials using a one-step microwave method. Guest molecules are embedded in a rigid cyanuric acid (CA) matrix formed from urea. By enhancing the conjugation of the guest molecules, a series of full-color URTP materials is successfully produced. These materials exhibit excellent phosphorescent properties, with a maximum phosphorescent lifetime of 7.96 s. Protected by the CA matrix, they retain phosphorescence even in aqueous environments, displaying an afterglow visible to the naked eye for over 30 s in water. Additionally, under low water content conditions, the materials exhibit exceptional water-enhanced properties, achieving a phosphorescence quantum yield (PhQY) of 40.4%. Importantly, these aqueous URTP materials can be prepared in just 5 min, showcasing great potential in information encryption and afterglow displays.