A multifunctional Eu MOF as a fluorescent pH sensor and exhibiting highly solvent-dependent adsorption and degradation of rhodamine B

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2015-01, Vol.3 (47), p.24016-24021
• Main Authors: Meng, Qingguo, Xin, Xuelian, Zhang, Liangliang, Dai, Fangna, Wang, Rongming, Sun, Daofeng
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C5TA04989J

Due to their tunable structure and porosity, metal–organic frameworks have provided a new platform for fluorescence sensing and adsorption/separation of gas or organic molecules. Many studies have focused on sensing metal ions, anions, or organic molecules through fluorescence quenching or enhancement of MOFs, but studies on pH-fluorescence sensors are seldom reported. Furthermore, highly solvent-dependent adsorption and degradation of dye molecules based on functional MOFs has not been explored to date. In this study, we describe a multifunctional Eu MOF, [H 3 O][Eu 3 (HBPTC) 2 (BPTC)(H 2 O) 2 ]·4DMA ( UPC-5 , UPC = China University of Petroleum [East China]) based on a tetracarboxylate ligand. The luminescence intensity of UPC-5 is strongly correlated with the pH value in the pH range from 7.5 to 10.0, and a linear relationship between pH value and fluorescent intensity is observed. Another attractive property of UPC-5 is that its Li-exchanged form, Li-UPC-5 , possesses solvent-dependent adsorption and degradation of rhodamine B. The highly efficient degradation or decolorization of rhodamine B with long-term stability and activity gives Li-UPC-5 a potential advantage in treating rhodamine B pollution.