Europium doped Ni(BTC) metal-organic framework for detection of heteroaromatic compounds in mixed aqueous media

In this paper, we have prepared europium doped Ni(BTC) (Ni = Nickel, BTC = 1,3,5- benzene tricarboxylic acid) MOF (Metal-Organic Framework), Eu@Ni(BTC). This MOF was characterized by PXRD (powder X-ray diffraction), FT-IR (Fourier-transform infrared spectroscopy), N₂ adsorption isotherm, TGA (thermogravimetric analysis), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy- Energy Dispersive Spectroscopy (FESEM-EDS) and Inductively coupled plasma mass spectrometry (ICP-MS). This MOF was then used as an optical sensor for the detection of heteroaromatic compounds. It was observed that the emission of Eu@Ni(BTC) was selectively and completely quenched by thiophene and partially quenched by pyrrole. The quenching efficiency of this sensor with thiophene and pyrrole was calculated to be 2.7 × 10⁵ and 7.5 × 10³, with a detection limit of 0.2 and 8.4 ppm, respectively. This sensor has recyclability up to five cycles and was also applied for the practical detection of thiophene from water.