Breaking the Interfacial Interaction Bottleneck: PVA-Engineered CDs-LDH Hybrids with Enhanced Time-Dependent Phosphorescence for Advanced Information Anti-Counterfeiting

Time-dependent phosphorescence color (TDPC) materials, characterized by persistent luminescence, high quantum yield, and superior optical performance, have attracted increasing attention for information encryption applications. However, achieving high performance room-temperature phosphorescence (RTP) remains challenging, as oxygen readily quenches triplet excitons and nonradiative decay pathways arising from molecular vibrations and rotations further suppress phosphorescence. In this study, we designed and integrated three functional components: luminescent carbon dots (CDs), layered double hydroxides (LDHs), and the polymer matrix poly(vinyl alcohol) (PVA). Owing to the synergistic interplay of multiple interactions, the CDs-LDH composites exhibit pronounced TDPC behavior. The confinement within LDHs and the electrostatic interactions between LDHs and CDs effectively restrict the motion of CDs and suppress aggregation-induced quenching, thereby laying the groundwork for RTP properties. Furthermore, interfacial electrostatic repulsion and hydrogen bonding within the CDs-LDH@PVA system collaboratively generate a rigid architecture that suppresses nonradiative decay pathways of triplet excitons, thereby enhancing TDPC. Benefiting from these synergistic effects, the CDs-LDH@PVA composite demonstrates an ultralong RTP lifetime of 87.81 ms, representing a significant performance breakthrough and providing a novel strategy for the design of high-efficiency organic–inorganic TDPC materials.