Matrix-Free and Highly Efficient Room-Temperature Phosphorescence Carbon Dots towards Information Encryption and Decryption.

Designing efficient room-temperature phosphorescence (RTP) carbon dots (C-dots) without the need of an additional matrix is important for various applications. Herein, matrix-free and highly efficient C-dots with yellow-green RTP emission have been successfully synthesized towards information encryption and decryption. Phytic acid (PA) and triethylenetetramine are used as molecular precursors, and a facile microwave-assisted heating method is selected as synthesis method. The obtained C-dots exhibit a maximum phosphorescence emission at around 535 nm under an excitation wavelength of 365 nm and a long average lifetime up to 750 ms (more than 9 s to the naked eye). PA containing six phosphate groups and serving as P source plays a significant role in producing the RTP C-dots. Furthermore, potential applications of the RTP C-dots in the field of information encryption and decryption are successfully demonstrated.