A Multifunctional Tb-MOF Detector for H2O2, Fe3+, Cr2O72–, and TPA Explosive Featuring Coexistence of Binuclear and Tetranuclear Clusters

A novel three-dimensional microporous terbium(III) metal-organic framework (Tb-MOF) named as [Tb10 (DBA)6(OH)4(H2O)5]·(H3O)4 (1), was successfully obtained by a solvothermal method based on terbium nitrate and 5-di(2',4'-dicarboxylphenyl) benzoic acid (H5DBA). The Tb-MOF has been characterized by single crystal X-ray diffraction, elemental analysis, thermogravimetry, and fluorescence properties, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. Structural analysis shows that there are two kinds of metal cluster species: binuclear and tetranuclear, which are linked by H5DBA ligands in two μ7 high coordination fashions into a three-dimensional microporous framework. Fluorescence studies show that the Tb-MOF can detect H2O2, Fe3+, and Cr2O72- with high sensitivity and selectivity and can also be used for electrochemical detection of exposed 2,4,6-trinitrophenylamine (TPA) in water. The highly selective and sensitive detection ability of the Tb-MOF might make it a potential multifunctional sensor in the future.