Imparting Tunable and White-Light Luminescence to a Nanosized Metal-Organic Framework by Controlled Encapsulation of Lanthanide Cations

An alternative way was demonstrated to fabricate highly luminescent MOFs and white-light emitter by encapsulating lanthanide(III) (Ln(3+)) cations into the channels of Al-MIL-53-COOH (1) nanocrystals. The framework can serve as both a host and an antenna for protecting and sensitizing the luminescence of the Ln(3+) cations. PXRD, TEM, FTIR, TGA, and N-2 adsorption measurements were performed to determine the structure, thermal stability, and BET surface area of the obtained products. The Ln(3+)-incorporated nanocrystals show strong emission under UV-light irradiation, and their luminescent properties were systematically studied. In contrast to the essentially unchangeable luminescence of lanthanide-based MOF, the luminescence of Ln(3+) @1 allows design and tuning. The versatile luminescence, good thermal stability, nanometer size, and compatibility with aqueous condition reveal these materials may have potential applications in LED lamps, barcoded materials, and biological sensors. In addition, the thin films of Ln(3+)@1 were prepared by chemical solution deposition (CSD) from their metastabilized colloidal solutions, which open the way to practical applications such as pellets and sensors for vapors.