A Facile One-Pot Approach to the Synthesis of Gd-Eu Based Metal-Organic Frameworks and Applications to Sensing of Fe3+ and Cr2O72− Ions

Abstract

Gadolinium metal-organic frameworks (Gd-MOFs) and Eu-doped Gd-MOFs have been synthesized through a one-pot green approach using commercially available reagents. The 1,4-benzenedicarboxylic acid (H2-BDC) and 2,6-naphthalenedicarboxylic acid (H2-NDC) were chosen as ditopic organic linkers to build the 3D structure of the network. The Gd-MOFs were characterized using powder X-ray diffraction (XRD), FT-IR spectroscopy, field emission scanning electron microscopy (FE-SEM) and N2 adsorption–desorption analysis. The Gd-MOF structures were attributed comparing the XRD patterns, supported by the FT-IR spectra, with data reported in the literature for Ln-MOFs of similar lanthanide ionic radius. FE-SEM characterization points to the effect of the duration of the synthesis to a more crystalline and organized structure, with grain dimensions increasing upon increasing reaction time. The total surface area of the MOFs has been determined from the application of the Brunauer–Emmett–Teller method. The study allowed us to correlate the processing conditions and ditopic linker dimension to the network surface area. Both Gd-MOF and Eu-doped Gd-MOF have been tested for sensing of the inorganic ions such as Fe3+ and Cr2O72−.

Adsorption Behavior of a Gd-Based Metal–Organic Framework toward the Quercetin Drug: Effect of the Activation Condition

“…Gd complexes, used as commercial diagnostic CAs today, have some downfalls such as low circulation time in the body, functionalization limits in case of need such as surface modification for crossing the blood–brain barrier, and toxicity due to high dose injection of Gd solution to get qualified contrasted images . To overcome these drawbacks, Gd-MOFs including Gd ions as nodes chelated with carboxylic ligands as struts are the best candidates for MRI agents thanks to their intense relaxivities due to the presence of a high concentration of Gd ions per MOF particle, biocompatibility because of the surrounding ligand which blocks interactions between toxic Gd ions and cell tissues, and facility of ligand modifications by specific peptides or polymers for targeted drug delivery, detection, or bioimaging. , Although Gd-MOFs have attracted much attention in the MRI field, their low specific surface area, for example, 2–11 m 2 /g, is considered disadvantage for use in drug delivery systems and theragnostic agents. − …”

“… 14 , 23 Although Gd-MOFs have attracted much attention in the MRI field, their low specific surface area, for example, 2–11 m 2 /g, is considered disadvantage for use in drug delivery systems and theragnostic agents. 24 − 26 …”

Ultrasound-Assisted Synthesis of Luminescent Micro- and Nanocrystalline Eu-Based MOFs as Luminescent Probes for Heavy Metal Ions

“…Small-sized crystals of the rare-earth-based MOFs are especially interesting due to their unique properties. Such materials have a large specific surface area, and as a result, they can effectively adsorb other ions and molecules, which is necessary for the development of sensitive luminescent sensors [ 17 , 18 , 19 ]. The presence of heavy metals in drinking water can cause numerous disorders and diseases of humans and animals [ 20 , 21 ].…”

Interfacial Coupling of Gadolinium-2-methylimidazole Metal Organic Framework and 2D-g-C3N4 Nanosheet for Synergistically Enhanced Bifunctional Oxygen Electrocatalysis

“…significantly, the shift of secondary and tertiary amine peaks (1335 and 1315 cm −1 ) of 2D-g-C 3 N 4 confirm the interaction between 2D-g-C 3 N 4 and Gd-2-mim/2D-g-C 3 N 4 . 32,40,41 The effective surface areas (S BET ) of 2D-g-C 3 N 4 , Gd-2-mim, and Gd-2-mim/2D-g-C 3 N 4 are determined by measuring the adsorbed gas volume using the N 2 monolayer adsorption− desorption equilibrium, as illustrated in Figure 2c. The S BET of Gd-2-mim/2D-g-C 3 N 4 is significantly higher, measuring 322.4 m 2 g −1 , compared to pristine 2D-g-C 3 N 4 (69.12 m 2 g −1 ) and Gd-2-mim MOF (93.5 m 2 g −1 ).…”