Two Novel Three‐Dimensional Tetraphenylethylene‐Based Rare Earth MOFs with Ultra‐High Proton Conductivity and Performance Stability

Abstract

In this work, the two example rare earth-based metal-organic frameworks (La III -based MOFs), Eu-ETTB and Gd-ETTB, were obtained by self-assembly. Both materials showed extremely high proton conductivity, with the proton conductivity of Eu-ETTB being 1.53 × 10 À 2 S cm À 1 at 98 % relative humidity (RH) and 85 °C and that of Gd-ETTB being 2.63 × 10 À 2 S cm À 1 at 98 % RH and 75 °C. This was almost the best performance observed for three-dimensional porous MOFs without post-synthetic modification and was based on milder conditions than for most materials. Furthermore, cycle test experiments and continuous work tests showed that both materials had excellent performance both in terms of stability and durability. Water vapor adsorption experiments showed that a large number of water molecules are adsorbed the hydrogen-bond network's being rebuilt by the adsorbed water molecules in the pore channel and thus optimizing the channels for proton transfer explained the MOF's high performance.

Highly proton-conducting lanthanide metal–organic frameworks featuring highly oxygenated ligands with slow magnetic relaxation or magnetocaloric effect

“…62,63 The magnetocaloric effect has been documented in Gd 2 systems featuring diverse molecule structures, including isolated complexes and coordination polymers. 64–70 To probe the potential MCE of Gd-MOF , M versus H plots were measured in the temperature range of 2–10 K (Fig. S21, ESI†), and the corresponding magnetic entropy change (−Δ S m ) versus temperature under different magnetic field differences was analyzed (Fig.…”

“…As far as we are aware, the Gd 2 magnetic cooling materials that have been documented are isolated systems, with few instances of Gd 2 -based coordination polymers demonstrating magnetic refrigeration (Table S5, ESI†). 68–70…”

Breathing Behavior and Superprotonic Conductivity of Two-Dimensional Flexible Metal–Organic Frameworks Tuned with Alkoxy Groups

“…To date, the most preferred designs for reported proton-conducting MOF materials involve constructing effective hydrogen-bonding networks to attain high carrier concentration and ion charge. These designs include constructing frameworks with organic ligands that contain hydrophilic groups (e.g., −COOH, −SO 3 H, −PO 3 H 2 , and −NH 2 ) or introducing acid guests (e.g., urea, sulfamic acid, imidazole, and inorganic acids) into frameworks. − From a crystallographic perspective, the self-adaption dynamic structural transformation of FMOFs is beneficial for maintaining hydrogen-bonding networks . Feng et al recently reported a case of FMOFs with high conductivity and demonstrated that conductivity can be improved through synergistic self-adaption between the dynamic torsion of alkyl sulfonic acid and dynamic breathing of FMOFs .…”

A Highly Stable Multifunctional Bi-Based MOF for Rapid Visual Detection of S2– and H2S Gas with High Proton Conductivity

“…MOFs are widely used in catalysis, , fluorescence sensing, , adsorption, proton conduction, , and other fields due to their high surface area, high porosity, excellent structural stability, and diverse structures. Currently, over 70000 MOFs have been reported, among which the metal centers to construct the majority of MOFs consist of transition metal elements, followed by rare earth elements.…”