A facile strategy to realize metal-free room-temperature phosphorescence by construct nitrogen doped carbon dots-based nanocomposite

Carbon dots (CDs) have received much attention in constructing metal-free phosphorescence materials, but it is still a huge challenge to develop a material with long lifetime and phosphorescence emission in aqueous environments. In this work, we designed and synthesized a universal approach to produce N-doped carbon dots (N-CDs) with efficient room-temperature phosphorescence (RTP) through simple heating treatment. Then, we prepared a kind of highly efficient N-CDs/MA nanocomposite phosphorescence materials by synthesized through N-CDs mixed with melamine. Excitingly, the characterizations indicate that the nanocomposite materials not only have an ultralong phosphorescence lifetime in the solid state, but also exhibit blue-green RTP in aqueous medium. In addition, based on their unusual RTP features, the obtained RTP materials can be successfully applied in ion determination and shows great potentials in the fields of anti-counterfeiting and information encryption.