Terbium-based metal organic framework and its immobilized nanofibrous membrane for selective detection and efficient removal of phosphate

Abstract

The detection and removal of phosphate were advantageous means to predict and mitigate eutrophication of aquatic ecosystems. In this study, a luminescent rod-like terbium-based metal organic frameworks (MOFs) had been synthesized successfully via facile hydrothermal reaction for convenient and efficient detection and adsorption of phosphate. Specifically, the Tb-based MOFs (Tb-BTC) exhibited high selectivity for sensing of phosphate through fluorescence quenching mechanism with the quenching constant values (Ksv) of 1.18 × 104 M−1 and low limit of detection (LOD) of 2.97 μM. Simultaneously, Tb-BTC also possessed superior adsorption ability for phosphate based on Langmuir isotherm model and pseudo-second-order kinetic model determining that the maximum adsorption capacity reached up to 222.2 mg/g with equilibrium time of 30 min. More significantly, Tb-BTC nanoparticle could be stably integrated into polyacrylonitrile (PAN) nanofibers for constructing hierarchically hybrid nanofibrous membrane (PAN/TB) through electrospinning to further improve its operability and recoverability. And the obtained customized membrane maintained selective detection for phosphate with visual LOD of 3 × 10−4 M and good capture of phosphate with the maximum adsorption capacity of 111.3 mg/g, respectively. Therefore, this study provided prospective candidate for detection and removal of phosphate making contribution at a certain level to predict and attenuate water eutrophication.