Eu(III) doped zinc metal organic framework material and its sensing detection for nitrobenzene

Abstract

An Eu(III) doped zinc metal-organic framework (MOF), i.e., Zn3(BTC)2: Eu(III), was synthesized by the solvothermal method. The crystal structure, morphology, compositions and photoluminescence properties of Zn3(BTC)2: Eu(III) were studied by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and optical spectroscopic technique, respectively. The sensing detection for different nitrobenzene concentrations is performed at room temperature. The results show that Zn3(BTC)2: Eu(III) is successfully synthesized, and 4% Eu(III) doped Zn3(BTC)2 exhibits the excellent fluorescence. The photoluminescence properties of activate Zn3(BTC)2: 4% Eu(III) in different solvents have been investigated in detail, and the results show that it has obvious fluorescence quenching behavior towards nitrobenzene (NB) in the range of 0-250 ppm, and the fluorescence intensity decreases exponentially when the NB concentration increases. According to the Stern-Volmer equation, the quenching constant KSV = 0.03873 ppm−1 (i.e., KSV = 3.957 × 103 M−1) can be obtained and the limit of detection is 0.97 ppm. The sensing mechanism is also discussed. The MOF sample shows rapid response, high sensitivity, good selectivity, good repeatability to NB, and may be used as a potential NB probe in liquid environment.