Eu-metal organic framework@TEMPO-oxidized cellulose nanofibrils photoluminescence film for detecting copper ions.

Metal-organic frameworks (MOFs) are emerging highly crystallized three-dimensional network complex formed by self-assembling metal ions and organic ligands. However, all MOFs are nanoscale and micro scale powder materials, which greatly impedes their further applications. In this study, a transparent Eu-MOF@TEMPO-oxidized cellulose nanofibrils (Eu-MOF@TOCNF) photoluminescence material for specifically detecting copper ions was fabricated via in-situ synthesis in hydroalcoholic medium. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Fluorescence spectrometer and other equipment were applied to characterize functionalized TOCNF film samples, and the results confirmed the successful fabrication of the functionalized TOCNF film with stable fluorescence properties. The film performed a high selectivity toward copper ion in the presence of other interfering metal ions. The fluorescence intensity of the film decreased gradually with the increase of copper ion concentration, and I0/I-1 developed a good linear relationship with [Cu2+], which made the film a promising material for detecting Cu2+ in water body.