Boron Nitride Dots In-situ Embedded in a B2O3 Matrix with the Long Lifetime Room-Temperature Phosphorescence in Dry and Wet States

Abstract Developing metal-free room-temperature phosphorescence (RTP) materials with ultralong lifetimes in dry and wet states simultaneously has been widely concerned due to their potential applications, which is also a tough challenge up to now. Herein, a smart construction strategy is proposed to in-situ embed boron nitride dots (BNDs) into an isogenous B2O3 matrix. The BND-based materials exhibit unexpected bluish-green RTP in solid and various wet conditions (water, oxidants, organic solvents, strong acids and bases). The RTP lifetime of them in powder is as long as ∼1.7 s, lasting over 10 s to naked eye. B2O3 matrix can not only uniformly disperse the BNDs in it, but also provide a rigid environment via forming hydrogen-bonded and covalently bonded interactions between them to strongly stabilize the triplet states excitions on the dots from nonradiative deactivation. More interestingly, RTP quenching of the BND-based powder in various solutions is effectively suppressed because the B2O3 matrix is not collapsed in them. For instance, the RTP lifetime in water is as long as ∼0.9 s. Based on the distinctive RTP properties in dry and various harsh wet states, the applications of the BND-based RTP materials in multi-level anti-counterfeiting and information encryption are demonstrated.