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Developing advanced sorbents for selective carbon dioxide (CO2) sequestration with minimal energy consumption remains a pivotal challenge. This study presents a novel strategy through transforming 3D bulk zirconium-porphyrin frameworks into the corresponding 2D nanosheet-assembled superstructures for enhanced CO2 capture. The hierarchical frameworks with well-organized nanosheet architectures exhibit significantly increased specific surface area from 600 m2/g to 2400 m2/g while providing kinetic benefits for gas diffusion. Compared to the adsorption behavior of the bulk counterparts, the nanosheet-assembled frameworks demonstrate a 1.5-fold increase in CO2 adsorption capacity without compromising CO2/N2 selectivity. Theoretical calculation reveals that the coordination unsaturated Zr-O clusters, electron delocalized environments both in interlayer gaps and micropores provided binding sites for CO2 capture. Our research demonstrates an adaptable structure-directed approach for the crystal engineering of metal-organic frameworks which would inspire the creation of state-of-the-art crystalline porous materials for broadened applications.

In order to manufacture effective supercapacitors with improved electrochemical performance, it is imperative to investigate greater surface area electrode materials. This work describes the development of a cost-effective method for the carbonization of porous zeolitic imidazole framework (ZIF8) to utilize as electrode of electrochemical supercapacitors. The electrode materials were prepared by synthesizing highly porous ZIF8-P followed by pyrolysis at 500 °C (ZIF8-P-500). The pyrolysis of ZIF-8 significantly strengthened the porous behavior by maintaining their hexagonal particles and obtaining high surface to volume ratio. The measurements using constant current charge/discharge (GCD) and cyclic voltammetry (CV) were used to evaluate the electrochemical capacitance characteristics of the synthesized ZIF8-P based electrode. The supercapacitor assembly using the optimized ZIF8-P electrode exhibited a high specific capacitance of ∼423.9 Fg–1 with exceptional cycle stability by maintaining capacitance of ∼86.7 % from its initial capacitance after 5000 cycles. Thus, the results indicate that the ZIF8-P based supercapacitor offers a compelling path for creating porous carbon electrodes from MOFs using low cost pyrolysis for advancing supercapacitor technology. [ABSTRACT FROM AUTHOR]

Developing efficient technologies to eliminate or degrade contaminants is paramount for environmental protection. Biocatalytic decontamination offers distinct advantages in terms of selectivity and efficiency; however, it still remains challenging when applied in complex environmental matrices. The main challenge originates from the instability and difficult-to-separate attributes of fragile enzymes, which also results in issues of compromised activity, poor reusability, low cost-effectiveness, etc. One viable solution to harness biocatalysis in complex environments is known as enzyme immobilization, where a flexible enzyme is tightly fixed in a solid carrier. In the case where a reticular crystal is utilized as the support, it is feasible to engineer next-generation biohybrid catalysts functional in complicated environmental media. This can be interpreted by three aspects: (1) the highly crystalline skeleton can shield the immobilized enzyme against external stressors. (2) The porous network ensures the high accessibility of the interior enzyme for catalytic decontamination. And (3) the adjustable and unambiguous structure of the reticular framework favors in-depth understanding of the interfacial interaction between the framework and enzyme, which can in turn guide us in designing highly active biocomposites. This Review aims to introduce this emerging biocatalysis technology for environmental decontamination involving pollutant degradation and greenhouse gas (carbon dioxide) conversion, with emphasis on the enzyme immobilization protocols and diverse catalysis principles including single enzyme catalysis, catalysis involving enzyme cascades, and photoenzyme-coupled catalysis. Additionally, the remaining challenges and forward-looking directions in this field are discussed. We believe that this Review may offer a useful biocatalytic technology to contribute to environmental decontamination in a green and sustainable manner and will inspire more researchers at the intersection of the environment science, biochemistry, and materials science communities to co-solve environmental problems.

Developing advanced sorbents for selective carbon dioxide (CO 2) sequestration with minimal energy consumption remains a pivotal challenge. This study presents a novel strategy through transforming 3D bulk zirconium-porphyrin frameworks into the corresponding 2D nanosheet-assembled superstructures for enhanced CO 2 capture. The hierarchical frameworks with well-organized nanosheet architectures exhibit significantly increased specific surface area from 600 m2/g to 2400 m2/g while providing kinetic benefits for gas diffusion. Compared to the adsorption behavior of the bulk counterparts, the nanosheet-assembled frameworks demonstrate a 1.5-fold increase in CO 2 adsorption capacity without compromising CO 2 /N 2 selectivity. Theoretical calculation reveals that the coordination unsaturated Zr-O clusters, electron delocalized environments both in interlayer gaps and micropores provided binding sites for CO 2 capture. Our research demonstrates an adaptable structure-directed approach for the crystal engineering of metal-organic frameworks which would inspire the creation of state-of-the-art crystalline porous materials for broadened applications. [Display omitted] Transforming 3D zirconium-porphyrin frameworks into 2D nanosheet-assembled superstructures enabling enhanced CO 2 adsorption capacity while providing kinetic benefits in gas diffusion. The 2D superstructures exhibited increased CO 2 adsorption capacity by 2.5 times compared to the bulk counterparts without sacrificing the CO 2 /N 2 selectivity. • A strategy to fabricate nanosheet-assembled zirconium-porphyrin superstructures. • Significantly increased specific surface area up to 2400 m2/g. • Enhanced CO 2 capture ability without compromising CO 2 /N 2 selectivity. • Theoretical calculation revealing the CO 2 adsorption mechanism. [ABSTRACT FROM AUTHOR]

Porous metal complexes enable single‐crystal X‐ray crystallographic observation of included guests or reaction intermediates through simple soaking with the guests/substrates. Previous studies on this technique have often encountered difficulties in the observation of chiral structures because the host frameworks had no chirality. We synthesized a new metal–peptide porous complex through a folding‐and‐assembly strategy and utilized the chiral pore for trapping chiral guests. Chiral alcohols and ketones were successfully included within the pore. Crystallographic analyses clearly revealed not only their chemical structures but also chiral transformation events within the pore such as fixed conformations or an unstable hemiacetal formation. [ABSTRACT FROM AUTHOR]

Porous single crystals which combine ordered lattice structures and disordered inter‐connected pores would provide an alternative to create twisted surface in porous microstructures. Now, transition‐metal nitride Nb4N5 and MoN single crystals are grown on a 2 cm scale to create well‐defined active structures at twisted surfaces. High catalytic activity and stability toward non‐oxidative dehydrogenation of ethane to ethylene is observed. Unsaturated metal–nitrogen coordination structures including Nb‐N1/5, Nb‐N2/5, Mo‐N1/3, and Mo‐N1/6 at the twisted surface mainly account for the C−H activation with chemisorption of H in molecular ethane at the twisted surface, which not only improves dehydrogenation performance but also avoids the deep cracking of ethane to enhance coking resistance. 11–25 % ethane conversion and 98–99 % ethylene selectivity is demonstrated without degradation being observed even after the operation of 50 hours. [ABSTRACT FROM AUTHOR]

In this Minireview, we discuss the fundamental chemistry of soft porous crystals (SPCs) by characterizing their common structural features and the resulting structural softness and transitions. In particular, we focus on the recently emerging properties based on metastable transitions and those arising from local dynamics. By comparing the resulting adsorption properties to those of commonly applied rigid adsorbents, we highlight the potential of SPCs to revolutionize adsorption‐based technologies, considering our current understanding of the thermodynamic and kinetic aspects. We provide brief outlines for the experimental and computational characterization of such phenomena and offer an outlook toward next‐generation SPCs likely to be discovered in the next decade. [ABSTRACT FROM AUTHOR]

Porous tantalum nitride (Ta3N5) single crystals, combining structural coherence and porous microstructure, would substantially improve the photoelectrochemical performance. The structural coherence would reduce the recombination of charge carriers and maintain excellent transport properties while the porous microstructure would not only reduce photon scattering but also facilitate surface reactions. Here, we grow bulk‐porous Ta3N5 single crystals on a two‐centimeter scale with (002), (023), and (041) facets, respectively, and show significantly enhanced photoelectrochemical performance. We show the preferential facet growth of porous crystals in a lattice reconstruction strategy in relation to lattice match and lattice channel. We present the facet engineering to enhance light absorption, exciton lifetime and transport properties. The porous Ta3N5 single crystal boosts photoelectrochemical oxidation of alcohols with the (002) facet showing the highest performance of >99 % alcohol conversion and >99 % aldehyde/ketone selectivity. [ABSTRACT FROM AUTHOR]

The sensitivity of conventional thin‐film OFET‐based sensors is limited by the diffusion of analytes through bulk films and remains the central challenge in sensing technology. Now, for the first time, an ultrasensitive (sub‐ppb level) sensor is reported that exploits n‐type monolayer molecular crystals (MMCs) with porous two‐dimensional structures. Thanks to monolayer crystal structure of NDI3HU‐DTYM2 (NDI) and controlled formation of porous structure, a world‐record detection limit of NH3 (0.1 ppb) was achieved. Moreover, the MMC‐OFETs also enabled direct detection of solid analytes of biological amine derivatives, such as dopamine at an extremely low concentration of 500 ppb. The remarkably improved sensing performances of MMC‐OFETs opens up the possibility of engineering OFETs for ultrasensitive (bio)chemical sensing. [ABSTRACT FROM AUTHOR]

Cyclohexane and cyclotri‐β‐alanyl have been used as scaffolds for the design of new C3‐symmetric rings incorporating conjugated alkenes and dienes. All three C3‐symmetric lactams share the same triangular shape and their crystal system is trigonal. They all belong to the R3 space group, R3m, R3 and R3c, for the increasingly large 12‐, 18‐ and 24‐membered rigid rings, respectively. All lactams stack on top of each other, through H‐bonds and van der Waals noncovalent interactions, leading to endless supramolecular cylinders and tubes. The largest member of the family leads to tubes, the central pores of which is wide enough to let water in. A common feature of all the lactams is their very large dipole, of around 9 D, according to DFT calculations. Surprisingly, all the resulting cylinders and tubes pack side by side in the crystals, with all the dipoles pointing to the same direction. As a result, all three crystals are anisotropic and appear to be the first members of a new kind of highly polar crystals. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of shape‐persistent organic cage compounds is often based on the usage of multiple dynamic covalent bond formation (such as imines) of readily available precursors. By careful choice of the precursors geometry, the geometry and size of the resulting cage can be accurately designed and indeed a number of different geometries and sizes have been realized to date. Despite of this fact, little is known about the precursors conformational rigidity and steric preorganization of reacting functional groups on the outcome of the reaction. Herein, the influence of conformational rigidity in the precursors on the formation of a [4+4] imine cage with truncated tetrahedral geometry is discussed. [ABSTRACT FROM AUTHOR]

The design of innovative porous crystals with high porosities and large surface areas has garnered a great deal of attention over the past few decades due to their remarkable potential for a variety of applications. However, heat dissipation is key to realizing their potential. We use systematic atomistic simulations to reveal that interpenetrated porous crystals formed from two-dimensional (2D) frameworks possess remarkable thermal conductivities at high porosities in comparison to their three-dimensional (3D) single framework and interpenetrated 3D framework counterparts. In contrast to conventional understanding, higher thermal conductivities are associated with lower atomic densities and higher porosities for porous crystals formed from interpenetrating 2D frameworks. We attribute this to lower phonon-phonon scattering and vibrational hardening from the supramolecular interactions that restrict atomic vibrational amplitudes, facilitating heat conduction. This marks a new regime of materials design combining ultralow mass densities and ultrahigh thermal conductivities in 2D interpenetrated porous crystals.

Porous crystals have great potential to exert space-specific functions such as multipoint molecular recognition. In order to rationally enhance the porous function, it is necessary to precisely control molecular recognition event in the pores. Hydrogen bonding is an effective tool for controlling molecular recognition. However, multiple hydrogen bonds, which are essentially the origin of high complementarity and specificity, remain difficult to innovate in porous crystals in an intelligent way. This paper demonstrates molecular recognition of amino acid and peptide derivatives by multipoint hydrogen bonding in a porous metal-macrocycle framework revealed by single-crystal X-ray diffraction analysis. l-Serine residues are site-selectively and residue-specifically adsorbed on the pore surface via multiple hydrogen bonds. A serine derivative is diastereoselectively recognized on the (P)- or (M)-side of the enantiomeric pore surface. Moreover, the conformation of the peptide is highly regulated, incorporating a poly-l-proline type I helix-like structure into the pore. These findings will bring deep scientific knowledge to the design of new porous crystals and functions., (© 2021 Wiley-VCH GmbH.)

Porous CuInS2 crystals were grown from starting materials CuCl2·2H2O, InCl3·4H2O and thiorea with ethylene glycol solution, that were placed into a flask, heated, and refluxed for 1 hour. The diffraction peaks only from CuInS2 phase appear for all the samples. The morphology of CuInS2 crystal was porous, and the porous crystals exist in two kinds. One kind was flower-like crystals which complexly lack the flakes, another one was sphere-like crystals existed with a number of the poles. The specific surface area of the samples grown by stirring starting materials with In to Cu ratio of 4.3 for 30 minutes was found approximately to be 55 m2/g. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

By combining physical measurements and molecular dynamics (MD) simulations, we investigated the dielectric properties of guest water molecules confined in the channels of porous coordination polymer crystals. [Ln2Cu3(IDA)6] · n H2O (Ln = La, Nd, Sm, Gd, Ho, Er; IDA = [NH(CH2COO)2]2-; n ≈ 9) exhibited large dielectric constants ( ε) and antiferroelectric behaviours at high temperatures. In particular, ε of [Sm2Cu3(IDA)6] · n H2O became as large as 1300 at around 400 K. In addition, the crystals exhibited broad dielectric peaks at around 170 K below which ε became very small, indicating the freezing of the positional freedom of guest water molecules. The dielectric constants of [Cu(IN)2] · n H2O (IN = (C6H4NO2)-) also increased fairly rapidly with temperature, which attributed to the melting of the hydrogen-bonded water chain system. These temperature dependences of ε were consistent with the results of MD simulation (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]