Calcination-Controlled Synthesis of Carbon Dots@MgF Composites with Yellow, White, and Ultraviolet-Blue Thermally Activated Delayed Fluorescence for Multilevel Information Encryption.

It is attractive but challenging to develop carbon dot (CD) based materials with tunable thermally activated delayed fluorescence (TADF), especially in the long wavelength region. Here, by simply calcinating the mixture of m-phenylenediamine and MgF at 300-500 °C, a series of CDs@MgF composites exhibiting yellow, white, and ultraviolet-blue TADF with high photoluminescence quantum yields of up to 37.6% are prepared.

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

Developing afterglow materials with wide-range and time-dependent colors is highly desirable but challenging. Herein, by calcinating the mixture of Rhodamine B and NHAl(OH)CO, carbon dots (CDs) are generated and in situ embedded in the porous AlO, forming the CDs@AlO 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.

Pyrolysis of Al-Based Metal-Organic Frameworks to Carbon Dot-Porous Al O Composites With Time-Dependent Phosphorescence Colors for Advanced Information Encryption.

Phosphorescent materials with time-dependent phosphorescence colors (TDPCs) have great potential in advanced optical applications. Synthesis of such materials is attractive but challenging. Here, a series of carbon dot-porous Al O composites exhibiting distinctive TDPC characteristics is prepared by high-temperature pyrolysis of Al-based metal-organic frameworks NH -MIL-101(Al).