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A novel microporous indium-based MOF material with unique 3-way rod-shaped secondary building units (SBUs), UTSA-22, was reported and exhibited high methane (CH4) and hydrogen (H2) storage. At 298 K and 65 bar, the total CH4 volumetric uptake of UTSA-22 is 174 cm3(STP) cm−3. Moreover, UTSA-22 shows a high CH4 working capacity of 146 cm3(STP) cm−3 in a pressure range of 5-65 bar at 298 K. In addition, UTSA-22 shows a high H2 gravimetric storage capacity (1.2 wt%) at 298 K and 100 bar.

Adsorptive separation is an appealing alternative technology to reduce the high energy and capital cost of the distillation separation of propylene/propane; however, it is very challenging to realize. A new flexible metal-organic framework (MOF) material [Zn2(BDC-Cl)2(Py2TTz)] with a doubly interpenetrated pillared paddle wheel structure of pcu (primitive cubic) topology has been realized for this difficult separation for the first time. Through a judicious choice of linkers, the framework has small pore apertures that lead to much more propylene adsorption than propane. The selective adsorption relies on the sieving effect of the flexible framework. The column breakthrough experiment further demonstrated that efficient separation can be achieved under dynamic conditions.

Metal-organic frameworks (MOFs) are promising materials for onboard hydrogen storage thanks to the tunable pore size, pore volume, and pore geometry. In consideration of pore structures, the correlation between the pore volume and hydrogen storage capacity is examined and two empirical equations are rationalized to predict the hydrogen storage capacity of MOFs with different pore geometries. The total hydrogen adsorption under 100 bar and 77 K is predicted as ntot = 0.085× Vp - 0.013× Vp 2 for cage-type MOFs and ntot = 0.076× Vp - 0.011× Vp 2 for channel-type MOFs, where Vp is the pore volume of corresponding MOFs. The predictions by these empirical equations are validated by several MOFs with an average deviation of 5.4%. Compared with a previous equation for activated carbon materials, the empirical equations demonstrate superior accuracy especially for MOFs with high surface area (i.e., SBET over ≈3000 m2 g-1 ). Guided by these empirical equations, a highly porous Zr-MOF NPF-200 (NPF: Nebraska Porous Framework) is examined to possess outstanding hydrogen total adsorption capacity (65.7 mmol g-1 ) at 77 K and record high volumetric working capacity of 37.2 g L-1 between 100 and 5 bar at 77 K.

Targeted at organic dye pollutants, a stable HOF was combined with an alginate (SA) hydrogel to enhance the affinity for cationic dyes. The as-obtained HOF@SA membrane (weight ratio: 1/1) shows a high adsorption capacity (729.21 mg g−1), adsorption selectivity and good recycling performance towards methylene blue. [ABSTRACT FROM AUTHOR]

Development of highly porous and robust hydrogen‐bonded organic frameworks (HOFs) for high‐pressure methane and hydrogen storage remains a grand challenge due to the fragile nature of hydrogen bonds. Herein, we report a strategy of constructing the double‐walled framework to target highly porous and robust HOF (ZJU‐HOF‐5a) for extraordinary CH4 and H2 storage. ZJU‐HOF‐5a features a minimized twofold interpenetration with double‐walled structure, in which multiple supramolecular interactions are existed between the interpenetrated walls. This structural configuration can notably enhance the framework robustness while maintaining its high porosity, affording one of the highest gravimetric and volumetric surface areas of 3102 m2 g−1 and 1976 m2 cm−3 among the reported HOFs so far. ZJU‐HOF‐5a thus exhibits an extremely high volumetric H2 uptake of 43.6 g L−1 at 77 K/100 bar and working capacity of 41.3 g L−1 under combined swing conditions (77 K/100 bar→160 K/5 bar), and also impressive methane storage performance with a 5–100 bar working capacity of 187 (or 159) cm3 (STP) cm−3 at 270 K (or 296 K), outperforming most of the reported porous organic materials. Single‐crystal X‐ray diffraction studies on CH4‐loaded ZJU‐HOF‐5a reveal that abundant supramolecular binding sites combined with ultrahigh porosities account for its high CH4 storage capacities. Combined with high stability, super‐hydrophobicity, and easy recovery, ZJU‐HOF‐5a is placed among the most promising materials for H2 and CH4 storage applications. [ABSTRACT FROM AUTHOR]

Biological ion channels are renowned for their exceptional ion transport selectivity and adaptability to environmental changes, posing a significant challenge for synthetic mimicry. Herein, an innovative covalent–organic‐framework membrane featuring aligned benzothiadiazole units within its oriented 1D nanochannels is reported. These densely arrayed dipolar benzothiadiazole units enhance selective ion adsorption and facilitate membrane charge regulation. Consequently, the membrane can dynamically adjust its permselectivity toward ions, transitioning seamlessly between cation‐selective, ambipolar, and anion‐selective states. This versatility affects both the type of ions transported and the transport efficiency, supporting reversible and controlled membrane operation, as illustrated by the capacity to regulate the magnitude and direction of osmotic power. When interacting with multivalent anions, highly negatively charged channels of the membrane exhibit outstanding cation permselectivity and conductivity. Specifically, upon exposure to PO43− ions, the membrane achieves a remarkable osmotic power of 155 W m−2 and an energy conversion efficiency of 46.1% under salinity gradients of 0.5 and 0.01 m NaCl. Notably, introducing multivalent cations can reverse the polarity of the membrane. This work underscores the potential of exploiting ion‐dipolar interactions for the development of adaptive, ion‐selective membranes with promising applications in electrochemical sensing, energy conversion, and more. [ABSTRACT FROM AUTHOR]

Purifying ultra‐high purity propylene (>99.995%) with an energy‐efficient adsorptive separation method is a promising yet challenging technology that remains unfulfilled. Instead of solely considering the effect of adsorbents on guest molecules, we propose a synergistic adsorption mechanism for the deep removal of propane and propyne, utilizing supramolecular interactions in both "host‐guest" and "guest‐guest" systems. Through modulation of the pore environment, Ni‐DMOF‐DM exhibits exceptionally high adsorption capacities for propane and propyne (171 and 197 cm3/g at ambient temperature and pressure, respectively), and unprecedented propane/propylene separation selectivity (2.74). Theoretical calculations confirm the geometric interactions of C‐H···π bonds and C‐H···O hydrogen bonds resulting from host‐guest interactions, alongside C‐H···H guest‐guest interactions within the confined pore space. Breakthrough experiments demonstrated that ultra‐high purity propylene (propane < 0.005% and propyne < 1.0 ppm) can be directly collected from ternary mixtures on Ni‐DMOF‐DM, achieving a productivity of up to 152.14 L/kg. [ABSTRACT FROM AUTHOR]

A tetraphenylethylene (TPE) derivative, TPEPhDAT, modified by diaminotriazine (DAT), was prepared by successive Suzuki–Miyaura coupling and ring-closing reactions. This compound exhibits aggregation-induced emission enhancement (AIEE) properties in the DMSO/MeOH system, with a fluorescence emission intensity in the aggregated state that is 5-fold higher than that of its counterpart in a dilute solution. Moreover, the DAT structure of the molecule is a good acceptor of protons; thus, the TPEPhDAT molecule exhibits acid-responsive fluorescence. TPEPhDAT was protonated by trifluoroacetic acid (TFA), leading to fluorescence quenching, which was reversibly restored by treatment with ammonia (on–off switch). Time-dependent density functional theory (TDDFT) computational studies have shown that protonation enhances the electron-withdrawing capacity of the triazine nucleus and reduces the bandgap. The protonated TPEPhDAT conformation became more distorted, and the fluorescence lifetime was attenuated, which may have produced a twisted intramolecular charge transfer (TICT) effect, leading to fluorescence redshift and quenching. MeOH can easily remove the protonated TPEPhDAT, and this acid-induced discoloration and erasable property can be applied in anti-counterfeiting. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have attracted significant attention in the realm of electronic energy storage and conversion owing to their remarkable theoretical energy density and cost‐effectiveness. However, Li–S batteries continue to face significant challenges, primarily the severe polysulfides shuttle effect and sluggish sulfur redox kinetics, which are inherent obstacles to their practical application. Metal‐organic frameworks (MOFs), known for their porous structure, high adsorption capacity, structural flexibility, and easy synthesis, have emerged as ideal materials for separator modification. Efficient polysulfides interception/conversion ability and rapid lithium‐ion conduction enabled by MOFs modified layers are demonstrated in Li–S batteries. In this perspective, the objective is to present an overview of recent advancements in utilizing pristine MOF materials as modification layers for separators in Li–S batteries. The mechanisms behind the enhanced electrochemical performance resulting from each design strategy are explained. The viewpoints and crucial challenges requiring resolution are also concluded for pristine MOFs separator in Li–S batteries. Moreover, some promising materials and concepts based on MOFs are proposed to enhance electrochemical performance and investigate polysulfides adsorption/conversion mechanisms. These efforts are expected to contribute to the future advancement of MOFs in advanced Li–S batteries. [ABSTRACT FROM AUTHOR]