A carbon dot-based time-dependent color-changing room temperature phosphorescent material

Carbon dots (CDs) based room-temperature phosphorescent materials have received extensive research attention due to their excellent optical properties, low biotoxicity and their great potential for applications in the field of anti-counterfeiting. However, only few CDs-based materials possessing time-dependent color-changing room-temperature phosphorescence (RTP) properties have been reported. In the present work, RTP composite materials with unique time-dependent color-changing properties were synthesized by a one-pot method using ethylenediaminetetraacetic acid (EDTA), boric acid (BA) and phosphoric acid (PA) as raw materials. The phosphorus-doped composites of carbon dots and boric acid (P-CDs@BA) possess yellow and green RTP properties. The coexistence of multiple luminescent centers and the difference in the phosphor lifetime and luminescence intensity of the luminescent centers make the P-CDs@BA composites possess unique time-dependent color change properties. Finally, a specific example of the application of P-CDs@BA composites in the field of anti-counterfeiting is given based on their time-dependent color-changing RTP properties. The present work provides ideas for the preparation of time-dependent color-changing carbon dot-based room temperature phosphorescent materials and their applications in the field of anti-counterfeiting.