N, S co-doped carbon dots with high quantum yield: tunable fluorescence in liquid/solid and extensible applications

摘要

A set of the highly fluorescent N, S co-doped carbon dots (NSCDs) were prepared through one-step hydrothermal synthesis at different temperature with citric acid as the carbon source and cysteamine as the N, S source. The NSCDs synthesized at 200 degrees C show significant quantum yield (81%) due to its optimal structure. The structure of the NSCDs changed with varying degrees of carbonization/aromatization and different content of multifunctional groups of C=O,-NH2, -OH,-SH, and N, S-aromatic heterocycte under different preparation temperatures, thus exhibiting tunable fluorescence. Especially, the obtained NSCDs exhibited a blue fluorescence in solution state and changed from strong blue to yellowish-green in its solid state under UV light as a result of the increase in preparation temperature. The as-prepared NSCDs can be used in selective detection of complex anions such as Cr2O72- and Fe(CN)(6)(3-), cell imaging, and preparation of fluorescent composite films.