Missing-linker engineering of Eu (III)-doped UiO-MOF for enhanced detection of heavy metal ions

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-03, Vol.431, p.134050, Article 134050
• Main Authors: Du, Ting, Wang, Jing, Zhang, Liang, Wang, ShaoChi, Yang, Chengyuan, Xie, Linxuan, Liu, Zhaoli, Ni, Yongsheng, Xie, XiangHong, Sun, Jing, Zhang, Wentao, Wang, Jianlong
• Format: Article
• Language: English
• Subjects: Heavy metal ions; Luminescent MOFs; Missing-linker defects; Precise trace detection
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.134050

A modulator-induced defect formation strategy was proposed to engineer luminescent lanthanide-based metal–organic framework (Eu@UIO-MOFs) and the missing-linker defects shows a positive regulation effect on the detection properties. By elaborately tailoring the defective numbers, Eu@UIO-MOFs-X with tunable structure is developed with remarkably enhanced response slope in the tiny detection window (0–10 ppm), acting as a powerful signal amplifier for trace detection of Cd2+. [Display omitted] •A modulator-induced defect formation strategy was proposed.•The elaborately tailored defect numbers are compared and quantitively interpretated.•The positive regulation was realized by structural defects.•The dual signal with reverse trend provides multiple insurance for precise detection.•The defective Eu@UiO-MOFs-2 with 0.53 missing linkers shows a LOD of 5.67 × 10−7 M. The creation of defects into luminescent MOFs allows for manipulation of fluorescent properties and thus leads to the enhanced detection performance for technological applications. Herein, a modulator-induced defect formation strategy was proposed to introduce missing-linker defect into lanthanide-based metal–organic framework (Eu@UiO-MOFs) and the enhanced detection properties was investigated. Notably, the missing-linker numbers in per Zr6 cluster were calculated to facilitate comparison and quantitively interpretation. By elaborately tailoring defect numbers, the resultant Eu@UiO-MOFs-2 sensor with 0.53 missing linkers per Zr-O cluster showed a remarkably enhanced response slope and realized excellent trace detection under the range of 0–10 ppm with ultralow detection limit to 5.67 × 10−7 M (114 ppb), acting as a powerful signal amplifier for trace detection of Cd2+. Moreover, the relationship between structural change and defect numbers of Eu@UiO-MOFs-X has been studied to understand the positive effect of the improved enrichment for the optical behavior. As far as we know, this is the first experimental demonstration of missing-linker defects in luminescent MOFs for regulation of optical sensing, offering a unique approach to explore innovative technologies for precisely detecting of heavy metal ion pollutants.