A multifunctional zinc-based metal-organic framework for sensing and photocatalytic applications

Abstract A multi-functional metal-organic framework (MOF) with the formula [Zn2(L)(4,4′-bpy)(CH3OH)(H2O)2]·3.5H2O·CH3OH(MOF1) (H4L = 2,5-bis-(3,5-dicarboxyphenyl)thiopheneamide,4,4′-bpy = 4,4′-bipyridine) has been successfully synthesized under solvothermal condition and characterized by single crystal X-ray diffraction analysis, IR spectroscopy, thermogravimetric analyses (TGA) and powder X-ray diffraction spectra (PXRD). This material exhibits strong fluorescent emission in the solid state and ethanol suspension at room temperature. Therefore, it is chosen as fluorescence probe for sensing aromatic amines and metal ions. The results reveal that MOF1 has dual-functional sensing performance, which can sense anilines and Al3+ as well Fe3+ ions selectively and reversibly through fluorescence enhancement or quenching effect. In addition, the photocatalysis activities of MOF1 and Fe3+ doped composite material (named Fe3+@MOF1) for degradation of Rhodamine B (RhB) were also studied. The experiment results show that Fe3+@MOF1 has the improved photocatalytic activity than MOF1, suggesting that doping Fe3+ ions into the framework of MOFs would be an ideal option for enhancing their photocatalytic activities.