Achieving blue water-dispersed room-temperature phosphorescence of carbonized polymer dots through nano-compositing with mesoporous silica

Stabilizing triplet excited states is important for room temperature phosphorescence (RTP) materials to achieve multifunctional applications in humid environment. However, due to the lack of preparation strategies, the realization of RTP materials in water still faces challenges. Herein, a new design strategy was presented to achieve RTP in water by confining carbonized polymer dots (CPDs) in amino functional mesoporous silica (MSNs-NH₂). The as-prepared MSNs-CPDs aqueous dispersion exhibited blue afterglow, lasting more than 3 s to naked eyes. The triplet excited states were protected from non-radiative deactivation by the double-confinement effect including covalent bonding fixation and mesoporous structure confinement. The MSNs-CPDs inherited the structure of MSNs-NH₂, so the stability of morphology and properties were superior to CPDs and even most of silica-based CPDs RTP materials. A water-related encryption technique demonstrated the promising application of MSNs-CPDs as smart materials in the field of information security. Besides, the possibility of potential application in ion detection was also explored.