An ultra-high quantum yield Tb-MOF with phenolic hydroxyl as the recognition group for a highly selective and sensitive detection of Fe3+. Issue 44 (3rd November 2021)

• Record Type: Journal Article
• Authors: Zhao, Yuming; Zhai, Xu; Shao, Lei; Li, Linlin; Liu, Yunling; Zhang, Xuemin; Liu, Jinhui; Meng, Fanbao; Fu, Yu
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 44(2021)
• Page Start: 15840
• Page End: 15847
• Publication Date: 2021-11-03
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc04311k
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : An ultra-high quantum yield Tb-MOF with phenolic hydroxyl as the recognition group for a highly selective and sensitive detection of Fe 3+ . Abstract : Lanthanide metal–organic frameworks (Ln-MOFs) have been considered as excellent fluorescence materials due to their ability of achieving a tunable fluorescence characteristic. Herein, based on the traditional chromogenic reaction between phenolic hydroxyl groups and Fe 3+, a novel luminescent Tb-MOF with high sensitivity and rapid detection of Fe 3+ was designed and synthesized using 2-hydroxyterephthalic acid (H2 BDC–OH) as the ligand by a facile dripping method. The obtained Tb-MOF possesses a three-dimensional interpenetrating network structure with a myriad of exposed phenolic hydroxyl, which provides abundant active sites for the specific recognition of Fe 3+ . As expected, the Tb-MOF shows a high sensitivity in the range of 0–100 μM with a low limit of detection (LOD) of 0.35 μM, an excellent selectivity against other interfering metal ions and a rapid response within seconds. The Tb-MOF also achieves an ultra-high quantum yield (QY) of 94.91% because of the good match between the lowest triplet state energy level of H2 BDC–OH and the 5 D4 energy level of Tb 3+, which is verified using density functional theory (DFT) calculations. Moreover, the Tb-MOF realizes a simple and convenient test paper in which the color change can be observed with the naked eye without expensive fluorescence instruments, providing an easy and reliable method for detecting Fe 3+ in daily applications. Finally, we proved that the rapid, highly sensitive and selective quenching of Tb-MOF for Fe 3+ is due to the specific recognition of the target Fe 3+ ions by the plentiful phenolic hydroxyl groups (abundant active sites), as well as the competitive energy adsorption between the ligands and Fe 3+ . This work lays a solid foundation for designing novel sensing materials to detect target molecules.