Fluorescent carbon dots doped with nitrogen for rapid detection of Fe (III) and preparation of fluorescent films for optoelectronic devices

The paper presents a green and easily prepared water-soluble fluorescent nitrogen doped carbon dots (N-CDs) synthesized by one-step hydrothermal process. The N-CDs displays brilliant blue fluorescence excited by UV light, with excellent water solubility, and a quantum yield of 15.7 %. The fluorescence intensity of N-CDs remains unchanged after 48 h of exposure to ultraviolet light, exhibiting good photostability. Moreover, the ion sensing characteristics of these N-CDs have been explored for more than a dozen anions and cations. The result reflects that this fluorescent CDs exhibits excellent sensitivity and selectivity for Fe3+ within a range spanning of 40 similar to 500 mu M with a limit of detection down to 0.22 mu M. The principle of sensor sensing is likely related to the formation of the internal filtering effect (IFE), which leads to a decline in the fluorescence intensity of N-CDs in aqueous solutions containing Fe3+. Due to the excellent water solubility, good photostability and high yield of N-CDs, the application of prepared N-CDs/polyvinyl alcohol (PVA) as fluorescent materials for white LED devices was explored. The prepared N-CDs/PVA (NCP) composite film can also exhibit bright blue light under 365 nm excitation, indicating good application prospects in the area of white LED devices and agricultural films.