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Chiral hybrid metal halides have emerged as a promising class of piezoelectric materials owing to their ease of synthesis, low acoustic impedance, and solution processibility. However, many known chiral halides crystalize in structures with only shear piezoelectricity which is less facile to be utilized compared with the longitudinal piezoelectricity, largely preventing their practical utility. In addressing this problem, chiral lead‐free S‐MPBiCl5 and R‐MPBiCl5 (MP = 2‐methylpiperazinium) with shear piezoelectricity are synthesized and the thin films orientating along the polarization direction are fabricated. These orientated films, characterized by numerous grains and compact grain boundaries, can effectively facilitate the grain boundary sliding to convert normal stress into shear stress, thus facilely activating the shear piezoelectricity. The resulting devices can accurately identify the position and type of ultrasound sources without the need for a complex acoustic impedance matching layer. Moreover, these devices can successfully sense delicate variations in momentum caused by table tennis balls. The findings open up a new pathway to utilize shear piezoelectricity that is normally considered unuseful of metal halides and other molecular piezoelectrics. [ABSTRACT FROM AUTHOR]

Supramolecular assembly frameworks (SAFs) represent a new category of porous materials, utilizing non‐covalent interactions, setting them apart from metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). This category includes but is not restricted to hydrogen‐bonded organic frameworks and supramolecular organic frameworks. SAFs stand out for their outstanding porosity, crystallinity, and stability, alongside unique dissolution‐recrystallization dynamics that enable significant structural and functional modifications. Crucially, their non‐covalent assembly strategies allow for a balanced manipulation of porosity, symmetry, crystallinity, and dimensions, facilitating the creation of advanced crystalline porous materials unattainable through conventional covalent or coordination bond synthesis. Despite their considerable promise in overcoming several limitations inherent to MOFs and COFs, particularly in terms of solution‐processability, SAFs have received relatively little attention in recent literature. This Minireview aims to shed light on standout SAFs, exploring their design principles, synthesis strategies, and characterization methods. It emphasizes their distinctive features and the broad spectrum of potential applications across various domains, aiming to catalyze further development and practical application within the scientific community. [ABSTRACT FROM AUTHOR]

Based on the electron‐withdrawing effect of the Pt(bpy)Cl2 molecule, a simple post‐modification amide reaction was firstly used to graft it onto the surface of NH2‐MIL‐125, which performed as a highly efficient electron acceptor that induced the conversion of the photoinduced charge migration pathway from internal BDC→TiOx migration to external BDC→PtNx migration, significantly improving the efficiency of photoinduced electron transfer and separation. Furthermore, precisely regulating over the first coordination sphere of Pt single atoms was achieved using further post‐modification with additional bipyridine to investigate the effect of Pt−Nx coordination numbers on reaction activity. The as‐synthesized NML‐PtN2 exhibited superior photocatalytic hydrogen evolution activity of 7.608 mmol g−1 h−1, a remarkable improvement of 225 and 2.26 times compared to pristine NH2‐MIL‐125 and NML‐PtN4, respectively. In addition, the superior apparent quantum yield of 4.01 % (390 nm) and turnover frequency of 190.3 h−1 (0.78 wt % Pt SA; 129 times compared to Pt nanoparticles/NML) revealed the high solar utilization efficiency and hydrogen evolution activity of the material. And macroscopic color changes caused by the transition of carrier migration paths was first observed. It holds profound significance for the design of MOF‐Molecule catalysts with efficient charge carrier separation and precise regulation of single‐atom coordination sphere. [ABSTRACT FROM AUTHOR]

Organic piezochromic materials that manifest pressure‐stimuli‐responses are important in various fields such as data storage and anticounterfeiting. The manipulation of piezofluorochromic behaviors for these materials is promising but remains a great challenge. Herein, a non‐luminous components regulated strategy is developed and organic molecular cages (OMCs), a burgeoning class of crystalline organic materials with structural dynamics, are first explored for the design of piezofluorochromic materials with tunable luminescence. A series of OMCs based on aggregation‐induced emission (AIE) chromophores, termed Cage 1–3, are synthesized and their piezofluorochromic behaviors are investigated by diamond anvil cell technique. Due to the sufficient voids between its flexible chromophores offered by the OMC structure, Cage 1 exhibits thermofluorochromic and piezofluorochromic properties. Moreover, the piezofluorochromic performance of this OMC could be further promoted by replacing its non‐luminous components with improved flexibilities, and a remarkable luminescence peak shift by 150 nm together with a response sensitivity of 13.8 nm GPa−1 was achieved upon hydrostatic compression. The cage structure plays a vital role in facilitating efficient and reversible piezofluorochromic behaviors. This study has shed light on the rational design and exploitation of OMCs as an exceptional platform to accomplish customizable piezofluorochromic behaviors and enlarge their potential applications in pressure‐based luminescence. [ABSTRACT FROM AUTHOR]

Pressure‐induced emission enhancement (PIEE) is a novel phenomenon in contrast to conventional pressure‐induced emission quenching, and has attracted considerable attention owing to the potential application of materials with this effect as optical pressure‐sensing devices. The urgent need and significant significance lie in the design and exploration of systems that possess high‐efficiency PIEE. Here, a large PIEE in a novel zero‐dimensional (0D) hybrid manganese bromide is realized, (BPPH)2MnBr4·1.5CH3CN [BPPH+ = bis(triphenylphosphine)iminium]. The experimental and theoretical results demonstrate that such emission enhancement is primarily attributed to the pressure‐induced reconfiguration of electronic band alignment and resultant redistribution of band‐edge excitons. Under compression, the electronic bandgap of (MnBr4)2− experiences a more rapid reduction compared to that of the organic cations. Consequently, this leads to the gradual closure of the charge transfer pathway from (MnBr4)2− to BPPH+. This progression results in a higher retention of excitons on (MnBr4)2−, amplifying the efficiency of Mn2+d–d transitions, and leading to a substantial enhancement in emission. This study not only offers fresh insights into the behavior of carrier dynamics induced by pressure in hybrid manganese halides but also presents a promising avenue for the advancement of PIEE systems. [ABSTRACT FROM AUTHOR]

Chiral hybrid organic–inorganic metal halides (HOMHs) offer an ideal platform for the advancement of second‐order nonlinear optical (NLO) materials owing to their inherent noncentrosymmetric structures. The enhancement of optical nonlinearity of chiral HOMHs could be achieved by matching the free exciton and/or self‐trapped exciton energy levels with desired NLO frequencies. However, the current scarcity of resonance modes and low resonance ratio hamper the further improvements of NLO performance. Herein, we propose a new resonant channel of charge transfer (CT) excited states from metal halide polyhedra to organic ligand to boost the second‐order optical nonlinearity of chiral HOMHs. The model lead halide (C7H10N)PbBr3 (C7H10N=1‐ethylpyridinium) exhibits a drastically enhanced second harmonic generation in resonance to the deep CT exciton energy, with intensity of up to 111.0 times that of KDP and 10.9 times that of urea. The effective NLO coefficient has been determined to be as high as ~40.2 pm V−1, balanced with a large polarization ratio and high laser damage threshold. This work highlights the contribution of organic ligands in the construction of a resonant channel for enhancing second‐order NLO coefficients of metal halides, and thus provides guidelines for designing new chiral HOMHs materials for advanced nonlinear photonic applications. [ABSTRACT FROM AUTHOR]

Purifying olefin from ternary paraffin/olefin/alkyne mixtures through a one‐step adsorption process is extremely desirable. Herein, a stable zirconium(IV) metal‐organic framework with a customized pore surface composed of nonpolar phenyl and slightly polar thiophene rings is reported to access the adsorption preference of paraffin and alkyne over olefin. Noteworthily, this material displays a superior ability to discriminate C3 hydrocarbon molecules, which is principally more challenging compared with C2 ones and rarely documented. Computational studies disclose that its featured pore shape fits well with C3 gas molecules, enabling them to get close contact with the immobilized affinity sites. Leveraging surface chemistry and pore shape engineering synergistically gives rise to excellent C3 adsorption capacities (>5 mmol g−1) and concurrently high C3H8/C3H6 (1.4) and C3H4/C3H6 (1.9) selectivities (at 298 K and 1 atm). Dynamic column breakthrough experiments demonstrate that one‐step purification of C2H4 and C3H6 can be simultaneously realized on this material. [ABSTRACT FROM AUTHOR]

To address the ever‐increasing societal demand for clean energy, electrocatalytic water splitting has attracted considerable interest for the efficient production of H2 and O2. However, the oxygen evolution reaction (OER) is inherently sluggish and poses a significant challenge to the overall water splitting process. As a result, extensive research efforts have been dedicated to pursuing various approaches in developing efficient electrocatalysts for water oxidation. The oxygen‐evolving center (OEC) of Photosystem II (PS II) is a natural model giving the prominent reference. Hence, this review discusses recent advances in the design of artificial electrocatalyst inspired by PS II. The discussion begins with a brief introduction to the fundamentals of electrocatalytic water oxidation and PS II. Subsequently, the progress of the novel electrocatalysts inspired by PS II is presented in the following two aspects: engineering various transition metal clusters to mimic the inorganic metal cluster of OEC (Mn4O5Ca), and utilizing different ligands to simulate the protein and amino acid environment around [Mn4O5Ca]. In addition to outlying the structures, catalytic activities, and corresponding mechanisms of these prepared catalysts, this present review concludes by proposing several effective development perspectives to this emerging field that warrant further investigation. [ABSTRACT FROM AUTHOR]

Hybrid organic−inorganic metal halides (HOMHs) have emerged as an ideal platform for the construction of semiconductor materials with promising optoelectronic properties. A number of HOMHs based on different metals including Sb3+ have been demonstrated with second‐harmonic generation (SHG) properties, but their nonlinear optical (NLO) performances including effective conversion wavelength range, optical stability, and NLO coefficients are not yet satisfactory. Here, by adopting a molecular design involving fluorine‐substitution on the achiral organic ammonium, this work has synthesized single crystals of two new chiral noncentrosymmetric HOMHs, (2‐FPEA)2SbX5 (X = Cl and Br), with large polarization ratios and outstanding optical transparency. The second‐order NLO coefficients of (2‐FPEA)2SbCl5 and (2‐FPEA)2SbBr5 are determined to be ≈24.3 and 21.6 pm V−1. Significantly, the Sb3+‐based HOMHs enable very high thermal stability and laser resistance. The distinguished laser‐induced damage thresholds (LDTs) have been estimated to be as high as 3.44 mJ cm−2 for (2‐FPEA)2SbCl5 and 3.32 mJ cm−2 for (2‐FPEA)2SbBr5, higher than that of the reported HOMHs. Such a highly efficient SHG performance and stability indicate the promising future of these Sb3+‐based metal halides for nonlinear photonic applications. [ABSTRACT FROM AUTHOR]

Chiral hybrid metal halides have been widely studied in the field of photondetectors, chiral optics, and spintronics due to their great structural flexibility and suitable bandgaps. Inspired by such great progress made in the abovementioned fields, continuous efforts need to be paid to seek other interesting applications for chiral hybrid metal halides. Herein, the synthesis of a pair of one‐dimensional enantiomorphic hybrid metal halide piezoelectrics, R/SMPCdCl4(R/SMP = R/S‐2‐methylpiperazine), and their applications in piezoelectric energy harvesting and sensing are reported. Density functional theory calculations show that these chiral piezoeletrics possess low elastic properties and high piezoelectric constants (16.71, 8.39, and 7.35 pC N−1). In addition, devices made of RMPCdCl4/PDMS (PDMS = polydimethylsiloxane) composite films are fabricated for piezoelectric energy harvesting and sensing. The piezoelectric energy harvesters with optimized content of 15 wt% RMPCdCl4/PDMS show not only excellent performance with an open‐circuit voltage of 2.57 V, short‐circuit current of 0.37 μA, and power density of 0.55 μW cm−2 but also outstanding stability of more than 3500 cycles. Meanwhile, these piezoelectric energy harvesters exhibit prominent sensing properties for detecting tapping, finger bending, walking, and running. It is demonstrated that chiral hybrid metal halides hold great potential in intelligent wearable and sensing devices. [ABSTRACT FROM AUTHOR]

Highly adjustable photonic modules were constructed based on the heterostructures crystals of a new series of donor‐acceptor metal–organic framework (D‐A MOF) featuring highly tunable thermally activated delayed fluorescence (TADF). By introducing N‐phenylcarbazole and derivatives as donor guests into the acceptor host NKU‐111, highly tunable through‐space charge transfer based TADF could be achieved through the engineering of heavy atom effect, which result in modulatable emission wavelength (540 to 600 nm) and enhanced quantum yield (up to 30.86 %). Furthermore, by rationally integrating the D‐A MOFs with distinctive emissions, rod‐like heterostructures crystals featuring excitation position dependent tip emissions in wide wavelength range (495 to 598 nm) could be fabricated, which could serve as highly potential photonic modules for photonic circuit applications. [ABSTRACT FROM AUTHOR]

Organic redox‐active materials are promising electrode candidates for lithium‐ion batteries by virtue of their designable structure and cost‐effectiveness. However, their poor electrical conductivity and high solubility in organic electrolytes limit the device's performance and practical applications. Herein, the π‐conjugated nitrogen‐containing heteroaromatic molecule hexaazatriphenylene (HATN) is strategically embedded with redox‐active centers in the skeleton of a Cu‐based 2D conductive metal–organic framework (2D c‐MOF) to optimize the lithium (Li) storage performance of organic electrodes, which delivers improved specific capacity (763 mAh g−1 at 300 mA g−1), long‐term cycling stability (≈90% capacity retention after 600 cycles at 300 mA g−1), and excellent rate performance. The correlation of experimental and computational results confirms that this high Li storage performance derives from the maximum number of active sites (CN sites in the HATN unit and CO sites in the CuO4 unit), favorable electrical conductivity, and efficient mass transfer channels. This strategy of integrating multiple redox‐active moieties into the 2D c‐MOF opens up a new avenue for the design of high‐performance electrode materials. [ABSTRACT FROM AUTHOR]

The mismatched fast‐electron‐slow‐proton process in the electrocatalytic oxygen evolution reaction (OER) severely restricts the catalytic efficiency. To overcome these issues, accelerating the proton transfer and elucidating the kinetic mechanism are highly sought after. Herein, inspired by photosystem II, we develop a family of OER electrocatalysts with FeO6/NiO6 units and carboxylate anions (TA2−) in the first and second coordination sphere, respectively. Benefiting from the synergistic effect of the metal units and TA2−, the optimized catalyst delivers superior activity with a low overpotential of 270 mV at 200 mA cm−2 and excellent cycling stability over 300 h. A proton‐transfer‐promotion mechanism is proposed by in situ Raman, catalytic tests, and theoretical calculations. The TA2− (proton acceptor) can mediate proton transfer pathways by preferentially accepting protons, which optimizes the O−H adsorption/activation process and reduces the kinetic barrier for O−O bond formation. [ABSTRACT FROM AUTHOR]

Chiral hybrid organic−inorganic perovskites (HOIPs) with intrinsic noncentrosymmetry have shown great potentials for chiroptoelectronic applications including second‐order nonlinear optics (NLO). Ideal NLO materials should simultaneously feature a large NLO coefficient, wide optical transparency, high laser damage threshold, and physicochemical stability. However, the development of applicable second‐order NLO materials has been largely restricted due to their strict requirement on structural noncentrosymmetry. Here, chiral amino acids abundant in nature have been adopted to synthesize hybrid lead halide perovskites (D‐/L‐Pro)PbI3·H2O (Pro = Proline) with resonance enhanced second‐harmonic generation (SHG). Their crystals feature balanced NLO performances with a large NLO coefficient, wide transparent region, high laser damage threshold, and high polarization ratio. This work demonstrates the promise of naturally abundant amino acids for the construction of hybrid chiral metal halide perovskites for next generation optoelectronic materials. [ABSTRACT FROM AUTHOR]

The chemical diversity and structural flexibility of lead halide perovskites (LHPs) offer tremendous opportunities to tune their optical properties through internal molecular engineering and external stimuli. Herein, we report the wide‐range and ultrapure photoluminescence emissions in a family of homologous 2D LHPs, [MeOPEA]2PbBr4−4xI4x (MeOPEA=4‐methoxyphenethylammonium; x=0, 0.2, 0.425, 0.575, 1) enabled through internal chemical pressure and external hydrostatic pressure. The chemical pressure, induced by the C−H⋅⋅⋅π interactions and halogen doping/substitution strengthens the structural rigidity to give sustained narrow emissions, and regulates the emission energy, respectively. Further manipulation of physical pressure leads to wide‐range emission tuning from 412 to 647 nm in a continuous and reversible manner. This work could open up new pathways for developing 2D LHP emitters with ultra‐wide color gamut and high color purity which are highly useful for pressure sensing. [ABSTRACT FROM AUTHOR]

Lanthanide metal–organic frameworks (Ln‐MOFs) are promising for luminescence detection of volatile organic compound (VOC) vapors, but usually suffer from the silent or quenched Ln3+ emission. Herein, we report a new dual‐emissive Eu‐MOF composed of the coordinatively unsaturated Eu9 clusters that afford abundant open metal sites to form a confined "binding pocket" to facilitate the preconcentration and recognition of VOCs. Single‐crystal structural analyses reveal that specific analytes can replace the OH oscillators in the first coordination sphere of Eu3+ and form a unique hydrogen‐bonding second‐sphere adduct tying adjacent Eu9 clusters together to minimize their nonradiative vibrational decay. With the promoted Eu3+ luminescence, the MOF realizes real‐time in situ visual sensing of THF vapor (<1 s) and shows a quantitative ratiometric response to the vapor pressure with a limit of detection down to 17.33 Pa. Also, it represents a top‐performing ratiometric luminescent thermometer. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Ammonia (NH3) is one of the most important industrial feedstocks in the fields of fertilizers, drugs, explosives, ordnance, commercial cleanings, and so on. However, the features of ammonia such as high toxicity and corrosivity, and difficulty in handling would inevitably increase the risk of environmental damage and the deterioration of natural/public lands. Although sorts of solid adsorbents such as metal oxides, zeolites, organic polymers, activated carbons, and metal organic frameworks have been applied in NH3 capture, they still show low uptake capacity, low affinities, and instability. Herein, we developed the first case of a highly stable sulfuric acid covalent organic framework (COF), namely TpBD‐(SO3H)2, as NH3 capturer, in which sulfonic acid sites can strongly interact with NH3 molecules, and enhance the performance of NH3 sorption. As a result, TpBD‐(SO3H)2 shows high chemical stability under strong acid and water conditions, an important merit for the potential application in harsh environment. And it also exhibits high ammonia capacity of 11.5 mmol·g−1 at 298 K and 1.0 bar, making it one of the best in all chemically stable NH3 adsorbents up to date. This work thus develops sulfuric acid COF materials as a new platform for ammonia capture and storage. [ABSTRACT FROM AUTHOR]

Developing universal stimuli‐responsive materials capable of emitting a broad spectrum of colors is highly desirable. Herein, we deliberately grafted a conformation‐adaptable organic chromophore into the established coordination space of a flexible metal–organic framework (MOF). In terms of the coupled structural transformations and the space confinement, the chromophore in the MOF matrix underwent well‐regulated conformational changes under physical and chemical stimuli, simultaneously displaying thermo‐, piezo‐, and solvato‐fluoro‐chromism with color tunability over the visible range. Owing to the resilient nature and the reduced dimensionality of the selected coordination space, all three color modulations behaved in a sensitive and self‐reversible manner, each following a linear correlation of the emission maximum with stimulus. Single‐crystal X‐ray diffraction of the variable‐temperature structures and solvent‐inclusion crystals elucidated the intricate color varying mechanisms. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The sequestration of organic luminescent molecules (OLMs) within cage‐based metal‐organic frameworks (MOFs) as a dispersion platform has been developed to impede aggregation‐caused quenching (ACQ). The homogenous encapsulation of distinct luminescent guests of different sizes and emissive behaviors in the cage structure of a MOF resulted in high fluorescent quantum yields of 44.8% for DAPI@NKU‐110 (DAPI = 4',6‐diamidino‐2‐phenylindole), 65.4% for TPPA@NKU‐110 (TPPA = tris(4‐(pyridin‐4‐ yl)phenyl)amine), 31.3% for R6G@NKU‐110 (R6G = Rhodamine 6G), and 58.3% for PY@NKU‐110 (PY = Pyronin Y), attributable to the confinement effect caused by the rigid cages of NKU‐110. More significantly, a positive correlation of the encapsulated quantity of OLMs with their concentration in the in‐situ solvothermal reaction was unveiled by spectral analysis and utilized to facilely fabricate a white‐light‐emitting crystal material TPPA+R6G@NKU‐110. This material features a large crystal size on the millimeter‐scale, broadband white emission, ideal CIE coordinates (0.33, 0.34), and a high quantum yield (49.1%) when excited at 365 nm. Moreover, such a strategy can be easily generalized to an abundance of other cage‐based MOFs and a plentiful volume of OLMs for the future development of colorful, high performance luminescent materials. [ABSTRACT FROM AUTHOR]

Chiral hybrid organic–inorganic metal halides (HOMHs) with intrinsic noncentrosymmetry have shown great promise for applications in second‐order nonlinear optics (NLO). However, established chiral HOMHs often suffer from their relatively small band gaps, which lead to negative impacts on transparent window and laser‐induced damage thresholds (LDT). Here, we have synthesized two chiral HOMHs based on CuI halides, namely (R‐/S‐MBA)CuBr2, which feature well‐balanced NLO performances with a highly efficient SHG response, outstanding optical transparency, and high LDT. The effective second‐order NLO coefficient of (R‐MBA)CuBr2 has been determined to be ≈24.7 pm V−1, which is two orders of magnitude higher than that of their CuII counterparts. This work shows the promising potential of CuI‐based chiral HOMHs for nonlinear photonic applications in wide wavelength regions. [ABSTRACT FROM AUTHOR]

Single‐crystal‐to‐single‐crystal (SCSC) phase transitions are direct structural evolutions of crystalline materials in the solid state without the damage of ordering in the crystal lattice. These multidimensional SCSC phase transition materials are responsive to multiple external stimuli (heat, light, mechanical force, electricity, etc.), and have therefore demonstrated promising applications in many fields such as sensors, actuators, artificial muscles, soft robotics, and energy harvesting. The directionality and cooperativity of intermolecular interactions in crystal structures together with a sustained and long‐range dynamics, and the fact that they can operate at high frequency, enable fast and efficient energy conversion processes in SCSC phase transition materials. In this review, the SCSC phase transition materials are analyzed by dividing them into different types of energy transformation, from the point of view of different stimuli that initiate and drive the phase transition, including the thermo‐, photo‐, electric‐, and mechanic‐induced energy transformation, and the dimensionality dependent characteristics in these processes are presented. Moreover, the state‐of‐the‐art design and fabrication of the SCSC phase transition materials as well as the mechanisms of their energy conversion processes are discussed. Finally, the challenges and future potentials are also discussed. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) and covalent‐organic frameworks (COFs) are two emerging families of functional materials used in many fields. Advantages of both include compositional designability, structural diversity, and high porosity, which offer immense possibilities in the search for high‐performance electrode materials for metal‐ion batteries. A large number of MOF/COF‐based cathode materials have been reported. Despite these advantageous features and research advances, MOFs/COFs and their derivatives face various challenges as cathode materials. In this review, an overview of the progress of MOF/COF‐based cathodes for advanced metal‐ion batteries is presented, including lithium‐ion batteries and other nascent technologies, such as sodium‐ion batteries, zinc‐ion batteries, aluminum‐ion batteries, and magnesium‐ion batteries. Research advances on the cathodes of MOFs/COFs and their derivatives are summarized in terms of active sites, structural design, and protective coatings. Perspectives and directions on the future development of MOF/COF‐based cathodes are outlined for meeting the requirements of practical applications. [ABSTRACT FROM AUTHOR]

Chiral hybrid perovskites have shown great potential for applications in next‐generation optoelectronic devices. The intrinsic asymmetric structures of these chiral hybrid perovskites make them particularly promising for second‐order nonlinear optics (NLO). However, it remains still a challenge to obtain ideal perovskite NLO crystals featuring simultaneously large NLO coefficient, good optical transparency, high laser damage threshold, and stable physical and chemical properties, which are highly desirable for practical applications. Herein, a series is constructed of 1D chiral lead halide hybrid perovskites (R/S‐2‐MPD)PbX3 (2‐MPD = 2‐methylpiperidine; X = Cl, Br, I) featuring non‐centrosymmetric architectures. Among them, the (R/S‐2‐MPD)PbBr3 perovskites demonstrate superior performances in second‐order optical nonlinearity, including a large second‐harmonic generation coefficient (≈29.9 pm V–1), wide transparency region (λUV ≈ 310 nm), high laser damage threshold (≈2.84 mJ cm–2), high polarization ratio (up to 96%), and robust physical and chemical stabilities. Such a balanced performance of the chiral lead halide perovskites promises their advanced application in next‐generation photonics devices. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) as a unique class of porous crystalline materials have received comprehensive attention in the past decades. Among them, luminescent MOFs (LMOFs) have been a well‐known branch on account of their relevance as optical materials in contemporary era. The establishment of host–guest hybrid LMOF materials has triggered a hot search area owing to the extensive range of applications that can be adjusted by soliciting different functional luminescent guests. Current developments in the thought‐provoking application of host–guest LMOFs have stretched into far‐ranging fields, including light regulation, imaging, sensing, data encryption, etc. This review discusses on the hybridization of MOFs with functional luminescent particles (LPs) as guests for the construction of a series of extraordinary host–guest luminescent composite materials (LP@MOFs). The basic aspects, involving the preconcentration of MOF hosts and luminous guests as well as the comprehensive synthetic strategies of LP@MOFs are introduced. Furthermore, the applications of luminescent LP@MOF materials are highlighted, with a particular emphasis on the present and continuing challenges and the demand trends of such materials that need to be explored. [ABSTRACT FROM AUTHOR]

2D hybrid organic–inorganic perovskites (HOIPs) are highly responsive to external stimuli and therefore have application potential as sensing materials. Though their optical properties upon singular thermal or pressure stimulation have been recently investigated, their dual‐stimuli‐responsive behaviors have not yet been explored. Here, the dual‐stimuli‐responsive luminescence of a pair of new enantiomeric 2D Dion–Jacobson HOIPs, R+[(4‐aminophenyl)ethylamine]PbI4 and S‐[(4‐aminophenyl)ethylamine]PbI4, is reported. The photoluminescence results show that their 485 nm emissions can be red‐shifted by ≈6 nm upon heating, and further increased to 529 nm under pressure. Such dual‐stimuli‐responsive emissions expand their Commission Internationale de L'Eclairage coordinates successively from (0.140, 0.272) to (0.283, 0.473). Detailed structural analysis and first principles calculations reveal that the temperature‐ and pressure‐responsive behaviors arise from the predominant electron–phonon interactions over thermal expansion effect and pressure‐induced in‐plane PbI bond contraction, respectively. The findings open up a new pathway to successively tune the optical emission of 2D HOIPs via a dual‐stimuli‐responsive approach. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Proton‐conductive metal‐organic frameworks (MOFs) have attracted great attention for their promising application in membrane fuel cells. To explore proton‐conductive MOFs with high performance, here we present four lanthanide‐hypophosphite frameworks with distinct amine guests. These complexes possess a general formula [AH][Gd2(H2PO2)7] (AH = protonated amines). Due to the rich hydrogen bond networks, complex 1 with guanidinium as guest shows high proton conductivity of 1.75 × 10–2 S·cm–1 at a relative humidity of 97% (368 K). We also studied the magnetic properties of complex 1 and reveal that the hypophosphite ligand transfers weak antiferromagnetic interactions between Gd3+ ions. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) have garnered enormous interest due to their remarkable catalysis activity. However, the exploitation of universal synthesis strategy and regulation of coordination environment of SACs remain a great challenge. Herein, a versatile synthetic strategy is demonstrated to generate a series of transition metal SACs (M SAs/NC, M = Co, Cu, Mn; NC represents the nitrogen‐doped carbon) through defect engineering of metal‐organic frameworks (MOFs). The interatomic distance between metal sites can be increased by deliberately introducing structural defects within the MOF framework, which inhibits metal aggregation and consequently results in an approximately 70% increase in single metal atom yield. Additionally, the coordination structures of metal sites can also be facilely tuned. The optimized Co SAs/NC‐800 exhibits superior activity and excellent reusability for the selective hydrogenation of nitroarenes, surpassing several state‐of‐art non‐noble‐metal catalysts. This study provides a new avenue for the universal fabrication of transition metal SACs. [ABSTRACT FROM AUTHOR]

The separation of n‐alkanes from their branched isomers is vitally important to improve octane rating of gasoline. To facilitate mass transfer, adsorptive separation is usually operated under high temperatures in industry, which require considerable energy. Herein, we present a kind of dynamic pillar‐layered MOF that exhibits self‐adjustable structure and pore space, a behavior induced by guest molecules. A combination of the flexibility of the framework with the commensurate adsorption for n‐hexane results in exceptional performance in separating hexane isomers. More significantly, lower temperature prompts the guest molecules to open the dynamic pores, which may provide a new perspective for optimized separation performance at lower temperatures with less energy consumption. [ABSTRACT FROM AUTHOR]

As one type of promising inorganic–organic hybrid crystal material, metal‐organic frameworks (MOFs) have attracted widespread attention in many potential fields, particularly in energy storage and conversion. Recently, effective strategies have been developed to construct uniform nanoscale MOFs (NMOFs), which not only retain inherent advantages of MOFs but also develop some improved superiorities, including shorter diffusion pathway for guest transportation and more accessible active sites for surface adsorption and reaction. Additonally, their nanometer size provides more opportunity for post‐functionalization and hybridization. In this review, recent progress on the preparation of NMOFs is summarized, primarily through bottom‐up strategies including reaction parameter‐ and coordination‐assisted synthesis, and top‐down strategies such as liquid exfoliation and salt‐template confinement. Additionally, recent applications of NMOFs in batteries as electrodes, separators, and electrolytes is discussed. Finally, some important issues concerning the fabrication and application are emphasized, which should be paid attention in future. [ABSTRACT FROM AUTHOR]

With the development of modern industry, global warming is becoming a challenging issue due to the emissions of large quantities of greenhouse gases, mainly carbon dioxide (CO2). The conversion of CO2 to useful compounds is considered as an effective and economic way to solve such a climate problem. Metal‐organic frameworks (MOFs) are an emerging class of porous crystalline materials that have shown great potential in the conversion of CO2. The advantages of MOFs in CO 2 conversion lie in their high surface areas, adjustable pore size, and high porosity. More importantly, desirable functional sites can be easily designed and precisely installed to the pore wall of target MOFs by pre‐assembly and/or post‐synthetic modification (PSM) ways. This review summarizes the recent advances in constructing MOF catalysts for the application in CO2 conversion. We believe that the design and synthesis of MOF catalysts for CO2 conversion can be a promising way to solve the "greenhouse effect". [ABSTRACT FROM AUTHOR]

2D metal‐organic frameworks (MOFs) have attracted broad research interest in recent years owing to their unique dimension‐related properties for widespread applications in catalysis, energy storage, conductivity, and optoelectronic devices. In this review, first the strategies for the rational design and precise construction of 2D MOFs are introduced. Then, the synthesis of 2D MOFs and their nanosheets by using top‐down and bottom‐up methods are summarized. Subsequently, the recent advances in optical/photonic applications of these 2D MOFs are highlighted, with special focus on lighting and display devices, nonlinear optics, as well as the luminescent sensing and biomedicine applications. Finally, the future potentials and challenges for the construction of 2D MOFs for optical materials are outlooked. [ABSTRACT FROM AUTHOR]

Developing active, stable, and cost‐effective water splitting catalysts is a critical step towards a sustainable energy future. Heterostructures of transition metal chalcogenides have emerged as important candidates for catalyzing oxygen evolution reaction (OER) or hydrogen evolution reaction (HER), due to the synergistic effects originating from the increased active sites or accelerated electron transfer. Current limitation to this strategy lies in the complication of synthesis often resorting to the direct growth of hybrid structures on a conductive current collector. Here, a simple approach is selected to synthesize graphitic carbon layer coated Ni3S2/MoS2 heterostructures (denoted as NMC) with a facile scaffold‐free solvothermal method followed by controlled pyrolysis. The NMC obtained at 600 °C behave as durable, efficient oxygen and hydrogen evolution electrodes with overpotentials of 350 mV and 233 mV respectively at 10 mA cm−2 in 1.0 M KOH. In addition, the catalysts demonstrate a high efficiency for overall water splitting. Such architected catalyst designs may shed light on the development of more efficient bifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]

Photonic materials use photons as information carriers and offer the potential for unprecedented applications in optical and optoelectronic devices. In this study, we introduce a new strategy for photonic materials using metal–organic frameworks (MOFs) as the host for the rational construction of donor–acceptor (D–A) heterostructure crystals. We have engineered a rich library of heterostructure crystals using the MOF NKU‐111 as a host. NKU‐111 is based upon an electron‐deficient tridentate ligand (acceptor) that can bind to various electron‐rich guests (donors). The resulting heterocrystals exhibit spatially segregated multi‐color emission resulting from the guest‐dependent charge‐transfer (CT) emission. Spatially effective mono‐directional energy transfer results from tuning the energy gradient between adjacent domains through the selection of donor guest molecules, which suggests potential applications in integrated optical circuit devices, for example, photonic diodes, on‐chip signal processing, optical logic gates. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: A synergistically directed assembly approach to distinctive metal‐organic frameworks utilizing both donor‐acceptor (D‐A) interaction from aromatic systems and coordination interactions is presented. Based on such an approach, the coronene‐tpt (tpt = 2,4,6‐tri(4‐pyridyl)‐1,3,5‐triazine) stacks based coronene‐MOF‐1—4 have been successfully fabricated. Their structural discrepancies with coronene‐ absent control products, 1′—4′, illustrate clearly the significance of coronene‐tpt based D‐A interactions in these architectures. All these coronene‐MOFs contain varied coronene‐tpt stacks as organic secondary building blocks (SBUs), which are closely interrelated with the coordination based framework structures. Moreover, porous coronene‐MOF‐1 and ‐2 exhibit high physicochemical stability and significant light hydrocarbons storage and separation performances. [ABSTRACT FROM AUTHOR]