Two Stable Pillar-Layered Zn-LMOFs for Highly Fluorescence Sensing of Inorganic Pollutants and Nitro Aromatic Compounds in Water

Luminescent metal-organic frameworks (LMOFs) are a potential class of functional materials for the photoluminescent detection of a wide range of analytes as well as for the detection of pollutants in wastewater. Herein, by using the pillar-layered strategy, two new luminescence Zn-LMOFs (<b>JLU-MOF222</b> and <b>JLU-MOF223</b>) were successfully solvothermal synthesized. The 2D layers are both consisting of Zn²⁺ and TPHC [TPHC = (1,1':2',1″-terphenyl)-3,3″,4,4',4″,5'-hexacarboxylic acid] ligands and then pillared by the different N-donor ligands to form the 3D Zn-LMOFs with <b>fsh</b> topology. Benefiting from the uncoordinated carboxylate sites, uncoordinated N atom, or -NH₂ group in the pillaring ligands and excellent stability in pH = 2-13 aqueous phase, <b>JLU-MOF222</b> and <b>JLU-MOF223</b> not only can sensitively detect trace amounts of inorganic pollutants (Fe³⁺, Cr₂O₇^2-) and nitro aromatic compounds TNP and 2,4-DNP (TNP = 2,4,6- trinitrophenol, 2,4-DNP = 2,4-dinitrophenol) through luminescence quenching but also exhibit high selectivity of other anti-interference competing analytes. The two new Zn-LMOFs can be used as potential luminescent sensors for pollutant detection in water due to their high <i>K</i>_SV and low limit of detection (LOD).