N-GQDs and Eu(3+) co-encapsulated anionic MOFs: two-dimensional luminescent platform for decoding benzene homologues

Highly luminescent hybrids N-GQDs/Eu(3+)@Mg-MOF (N-GQDs = N atom doped graphene quantum dots and Mg-MOF = {[Mg3(ndc)2.5(HCO2)2(H2O)][NH2Me2]·2H2O·DMF}) have been synthesized and their photophysical properties were investigated. The resulting luminescent material can exhibit dual-emission from N-GQDs and Eu(3+) when excited at 394 nm, whereas the emission of ligand-based and Eu(3+) can be collected when excited at 349 nm. Exposed to a series of atmospheric benzene homologues (BTEX) in a sealed environment for 1 hour at 25 °C, N-GQDs/Eu(3+)@Mg-MOF shows excellent fingerprint correlations between the exact BTEX and the emission peak height ratio of IL/IEu (luminescent intensity ratio of ligand-based emission at 414 nm and Eu(3+)-based emission at 618 nm) and IEu/IN-GQDs (luminescent intensity ratio of l-emission based on N-GQDs at 443 nm and Eu(3+)-based emission at 618 nm), which makes it possible for this material to become a good platform for the detection of BTEX.