A Multifunctional Tb‐MOF for Highly Discriminative Sensing of Eu3+/Dy3+ and as a Catalyst Support of Ag Nanoparticles

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 13; no. 22
• Main Authors: Xu, Guo‐Wang, Wu, Ya‐Pan, Dong, Wen‐Wen, Zhao, Jun, Wu, Xue‐Qian, Li, Dong‐Sheng, Zhang, Qichun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 13.06.2017
• Subjects: 4‐nitrophenol; Ag@MOF composite; Catalysts; Detection; Dysprosium; Europium; Fluorescence; Ion exchange; Magnetic properties; Nanomaterials; Nanoparticles; Nanotechnology; Nitrophenol; Particulate composites; Rare earth elements; Reduction (metal working); sensors; Silver; Sorption; Tb‐MOFs; Terbium
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201602996

Exploring novel multifunctional rare earth materials is very important because these materials have fundamental interests, such as new structural facts and connecting modes, as well as potential technological applications, including optics, magnetic properties, sorption, and catalytic behaviors. Especially, employing these nanomaterials for sensing or catalytic reactions is still very challenging. Herein, a new superstable, anionic terbium‐metal–organic‐framework, [H2N(CH3)2][Tb(cppa)2(H2O)2], (China Three Gorges University (CTGU‐1), H2cppa = 5‐(4‐carboxyphenyl)picolinic acid), is successfully prepared, which can be used as a turn‐on, highly‐sensitive fluorescent sensor to detect Eu3+ and Dy3+, with a detection limitation of 5 × 10−8 and 1 × 10−4m in dimethylformamide, respectively. This result represents the first example of lanthanide‐metal–organic‐frameworks (Ln‐MOF) that can be employed as a discriminative fluorescent probe to recognize Eu3+ and Dy3+. In addition, through ion exchanging at room temperature, Ag(I) can be readily reduced in situ and embedded in the anionic framework, which leads to the formation of nanometal‐particle@Ln‐MOF composite with uniform size and distribution. The as‐prepared Ag@CTGU‐1 shows remarkable catalytic performance to reduce 4‐nitrophenol, with a reduction rate constant κ as large as 2.57 × 10−2 s−1; almost the highest value among all reported noble‐metal‐nanoparticle@MOF composites. A new porous, anionic Tb‐metal–organic‐framework, China Three Gorges University (CTGU‐1), can serve as a turn‐on sensor for detection of Eu3+ and Dy3+, with different detection limits. Additionally, spontaneous in situ reduction and immobilization of ion‐exchanged Ag(I) to Ag nanoparticles in the anionic framework result in an Ag@CTGU‐1 composite, which can remarkably catalyze the reduction of 4‐nitrophenol.