Effect of transition metal ions on luminescence of MOFs

Abstract

Three kinds of metal-organic framework materials (MOF-5, MLI-101(Cr), UiO-66) are synthesized, which are based on transition metal (Zn, Cr, Zr) as the center ions, and terephthalic acid (H2BDC) as organic ligand. At the same time, three kinds of MOFs were characterized and analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible absorption spectrometer (UV-Vis), and fluorescence spectrometer (PL). This article analyzes the fluorescence effects of these three MOFs and investigates the role of different transition metal ions in MOF luminescence. The results show that the ionic radii of Zn2 + and Zr4 + are similar, which are 0.074 nm and 0.072 nm, respectively. MOF-5 and UiO-66 have similar fluorescence effects, both of which emit blue-violet light. However, MIL-101 (Cr) fluorescence centers on Cr3 + with an ionic radius of 0.0651 nm emits yellow-green light, which is different from the foregoing MOFs. Therefore, the ionic radius of the transition metal has an important effect on the fluorescence effect of the MOF. For larger ionic radii, the fluorescence of MOF is generally in the blue-violet square region.

Metal‐Organic Frameworks (MOFs) and their Applications in CO2Adsorption and Conversion

“…Last but not least, Ruan and co-workers [64] studied the effect of transition metals on the luminescence characteristics of MOFs. MOF-5, MIL-101(Cr), and UiO-66 were synthesized by using H 2 BDC as the organic ligand and Zn 2 + , Cr 3 + , and Zr 4 + as the central ions.…”

Binding of CsPbBr3 Nanocrystals to MOF-5 for the Detection of Cadmium Ions in Aqueous Media

“…28 structure composed of terephthalic acid (H 2 BDC) as a linker (the most common and simplest) and Zn 4 O as a metal cluster. 29 It shows excellent bonding with common donor atoms such as O and N. 30 Its open skeletal structure, controllable pore structure, and high surface area make it a widely studied material for applications in gas storage, gas separation, electrochemistry, catalysis, and medicine. In this study, an in situ technique is developed for the insertion of highly luminescent perovskite CsPbBr 3 nanocrystals (CNCs) into MOF-5 as a MOF:CNC composite, which is a stable guest−host system.…”

“…MOF-5 (Zn-MOF) is one of the standard representatives of the MOF family . It has a three-dimensional framework structure composed of terephthalic acid (H 2 BDC) as a linker (the most common and simplest) and Zn 4 O as a metal cluster . It shows excellent bonding with common donor atoms such as O and N .…”