席夫碱功能化MIL-101(Fe)的制备及其对水中磷酸根的荧光检测OA北大核心CSTPCD

Developing a simple and rapid method for phosphate(PO43-)detection is imperative to address eutrophication problems of water bodies.Metal-organic frameworks(MOFs)have drawn increasingly attentions as fluorescence sensors due to their good thermal stability,high specific surface area,flexible modifiable structures and tunable porosity.The Schiff base-functionalized metal-organic framework material MIL-101(Fe)-Schiff was prepared by post-synthetic modification method,and its structure and morphology were characterized by XRD,FT-IR,SEM-EDS,TEM and XPS.The fluorescence properties of MIL-101(Fe)-Schiff and its performance on fluorescence detection of phosphate were further investigated by UV-vis absorption spectroscopy and fluorescence spectroscopy.The results showed that MIL-101(Fe)-Schiff had a good fluorescence stability and could achieve the fluorescence enhanced detection of phosphate in aqueous solution with the preferable sensitivity and specificity.Under the optimal conditions,MIL-l0l(Fe)-Schiff showed a good linear correlation between the luminescence intensity and phosphate concentration(correlation coefficient R2=0.9979),within a linear range of 0.01-1 mmol·L-1 and a low detection limit(LOD)of 4.82 μmol·L-1(S/N=3).It also showed a good phosphate detection performance in practical applications.The fluorescence enhancement effect induced by phosphate was mainly attributed to the coordination and hydrogen bonding interactions between Fe-oxo,imine groups on MIL-101(Fe)-Schiff and phosphate,respectively.This study can provide a reference for the further development and application of convenient fluorescence methods for in-situ detection of phosphate.