Full‐Color Dynamic Afterglow in Carbon Dot‐Based Materials Regulated by Dual‐Phosphorescence Resonance Energy Transfer

Abstract Developing afterglow materials with wide‐range and time‐dependent colors is highly desirable but challenging. Herein, by calcinating the mixture of Rhodamine B and NH 4 Al(OH) 2 CO 3 , carbon dots (CDs) are generated and in situ embedded in the porous Al 2 O 3 , forming the CDs@Al 2 O 3 composite, which exhibits time‐dependent phosphorescence colors (TDPCs) from blue to green after excited by a UV lamp. Photophysical studies reveal that the blue phosphorescence with a short lifetime of 214 ms originates from the carbon core state, while the green phosphorescence with a long lifetime of 915 ms is associated with the surface state of CDs. Simultaneous activation of the blue and green phosphorescence with different lifetimes induces the TDPC performance. Using CDs@Al 2 O 3 as the donor, a series of long‐wavelength fluorescent dyes including Rhodamine 123, Rhodamine 6G, and Rhodamine B as the acceptors, and epoxy resin (ER) as the matrix, a dual‐phosphorescence resonance energy transfer system (CDs@Al 2 O 3 ‐dye‐ER) is constructed to rationally regulate the afterglow emission, conferring the full‐color dynamic afterglow from blue to red at different decay times with high afterglow quantum yields of up to 48.2%. The fascinating afterglow properties of the CDs@Al 2 O 3 ‐dye‐ER composites enable their successful applications in multidimensional information encryption and polychrome 3D artworks.