Facile Preparation of Long-Lifetime and Stable Carbon Dots-Alumina Room-Temperature Phosphorescent Materials by One-Step Temperature-Programmed Calcination

Phosphorescent materials are widely used in biosensing, light-emitting devices, information encryption, and anticounterfeiting. Among materials, room-temperature phosphorescence (RTP) based on carbon dots (CDs) has made great progress in recent years, but cannot maintain phosphorescence emission in water environments. Therefore, the design and synthesis of CDs-based RTP materials with tunable and stable emissions in water are important for advanced applications. Herein, novel RTP CDs hybrid materials (ATPA-CDs@Al2O3) were obtained by a one-step method by calcining mixed 2-aminoterephthalic acid and Al(OH)3. The dense structure of Al2O3 during the calcination process resulted in the formation of ATPA-CDs@Al2O3 with an RTP emission. ATPA-CDs@Al2O3 exhibited a color change from blue to green under excitation wavelengths from 254 to 394 nm (excitation-dependent RTP emission). More importantly, ATPA-CDs@Al2O3 displayed a long phosphorescence lifetime (0.84 s), as well as stable phosphorescence in HCl, NaOH, and organic solvents, thereby demonstrating potential for use in information encryption, anticounterfeiting, and fingerprint recognition.