| Metal-organic Frameworks materials is a kind of high porosity,macroporous structure controlled,chemical properties of stable and simple preparation process of new type of porous crystalline luminescent materials.The material has the advantages of fast detection speed,high sensitivity,good selectivity,stability and reliability in fluorescence sensing detection of pollutants.In addition,the luminescent metal organic frameworks with different functional groups can provide a protective support to avoid the hydration quenching of lanthanide ion in the host guest system.In this paper,we selected 4,4’-stilbenedicarboxylic acid(L1)and 2,5-bis-(3,5-dicarboxyphenyl)thiopheneamide(L2)as the organic linkers to synthesize three MOFs with d10 transition metal ions:Zn3(L1)3(DMF)2(MOFl)、Zn3(L1)3(DMA)2(H2O)3(MOF2)and[Cd2((H2L)2(H2O)5]·5H2O·2DMF(MOF3).By infrared spectroscopy(FT-IR),X-ray powder diffraction(PXRD),thermogravimetric(TG)and elemental analysis(EA)to characterize and analysis the luminescent metal-organic frameworks materials.Their optical properties are also a studied by fluorescence spectroscopy(PL).In this work,two solvent-induced Zn(II)-based luminescent metal-organic frameworks,Zn3(L1)3(DMF)2(MOF1)and Zn3(L1)3(DMA)2(H2O)3(MOF2),were investigated as selective sensing materials for detection of nitroaromatic compounds and metal ions.The sensing experiments show that MOF1 and MOF2 both exhibit selective fluorescence quenching toward p-nitroaniline with a low detection limit.In addition,MOF1 exhibits high selectivity for detection of Fe3+ and Al3+ by significant fluorescence quenching or enhancement effect.While for MOF2,it only exhibits significant fluorescence quenching effect for Fe3+.In addition,it is found that MOF1 and MOF2 have good cycle stability and anti-interference.The results indicate that MOF1 and MOF2 are both promising fluorescence sensors for detecting and recognizing nitroaniline and metal ions with high stability,selectivity and sensitivity.Studied the luminescent metal-organic frameworks MOF3 fluorescence sensing detection performance of nitroaromatic compounds and metal ions as well as sensitization effect of lanthanide ion.The results show that MOF3 has high selectivity,high sensitivity,anti interference and cycle stability for Fe3+ ion and p-nitroaniline fluorescence sensing.For the sensitization study of lanthanide ion in aqueous solution,MOF3 has a good effect on the sensitization of Eu3+ ions in aqueous solution,the in-depth study found that with the increase of concentration and time of sensitization sensitization effect better,and in the UV lamp showing a naked eye visible fluorescent color changes from blue to red realized can be adjusted launch. |
