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Metal–organic frameworks (MOFs) have been widely studied as new materials, and many structural regulation strategies have been reported. We report a new defective-MOF design strategy that involves a continuous process of pore space partition, metal center exchange, and ligand removal. In the whole process, the single crystal of MOF is well maintained, which not only points out a rare and clear route for the structure transformation process but also provides an indirect synthesis method for defective materials, which cannot accurately control the vacancy position. It was interesting to find that the removal of the selected ligand endows the MOF with larger pores, higher stability and excellent performance in the selective adsorption and separation of C2H4/C3H6 mixtures and natural gas mixtures. [ABSTRACT FROM AUTHOR]

The exploration and development of electrocatalysts with high utilization of active sites toward the oxygen reduction reaction (ORR) is crucial for zinc–air batteries. Nitrogen-doped carbon catalysts have emerged as attractive candidates. However, they suffer from low utilization of active sites since the bulk carbon matrix exhibits numerous mass transfer 'dead zones'. Herein, a thermal exfoliation and etching strategy is employed to synthesize an accordion-like N-doped carbon nanomesh (A-NC-M) using a novel multilayer two-dimensional (2D) zeolitic imidazolate framework (ZIF) as the precursor rather than a conventional bulk three-dimensional (3D) ZIF. The as-prepared A-NC-M inherits the multilayer 2D shape of the ZIF precursor and has a unique hierarchically interconnected nanomesh structure with many mesopores and micropores. Taking advantage of the high utilization of active sites, large surface areas (1512.3 m2 g−1), and fast mass/electron transport of the 2D layered structure, A-NC-M as an ORR electrocatalyst displays a half-wave potential of 0.899 V in 0.1 M KOH, surpassing the benchmark Pt/C by 42 mV. The zinc–air battery assembled by the A-NC-M catalyst delivers a higher power density and specific capacity than those of Pt/C. This study provides insight into the rational construction of novel carbon nanostructures for extended electrocatalytic and energy applications. [ABSTRACT FROM AUTHOR]

Two Ni-added poly(polyoxometalate)s built of Keggin-type {Ni6PW9} and Anderson-type NiW6O24 units via WO4/Sb2O bridges and Ni–O–W linkages, Na4H8[Ni(enMe)2][(Sb2O)2(NiW6O24)-{Ni12O2(OH)4(enMe)4(H2O)3(WO4)2(B-α-PW9O34)2}2]·39H2O (1) and H9[Ni(en)2(H2O)][Ni0.5(en)2(H2O)][Ni-(enMe)2(H2O)][(Sb2O)2(NiW6O24){Ni12O2(OH)4(en)2(enMe)2(H2O)3(WO4)2}-{Ni12O2(OH)4(en)4(H2O)3(WO4)2}(B-α-PW9O34)4]·45H2O (2), have been hydrothermally synthesized and characterized, in which the {Ni12(WO4)2(PW9)2} subunit was obtained by the synergistic directing effect of 2 lacunary PW9O34 (PW9) fragments and further linked by a central Anderson-type (Sb2O)2(NiW6O24) bridge. Both compounds represent the first example of Ni-added polyoxometalates (POMs) simultaneously based on Keggin-type and Anderson-type POM components. Photocatalytic studies revealed that 2 can work as an efficient heterogeneous catalyst towards a light-driven H2 evolution reaction, achieving a hydrogen evolution rate of as high as 19 214 μmol g−1 h−1 (TON = 1500), which is superior to most of the reported POM-based heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Owing to their low viscosity, low corrosion risk, and low cost, ultralow-concentration electrolytes for rechargeable alkali-metal-ion batteries have received much research interest. Herein, we report an ultralow-concentration electrolyte (<0.1 M) for K-ion batteries (KIBs). Using the electrolyte with only 0.05 M potassium bis(fluorosulfonyl)imide (KFSI) in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) as an example, we found that KIBs with this ultralow-concentration electrolyte could deliver considerable electrochemical performance over a wide range of temperature (0–60 °C). The delivered specific capacities and cycling performances of KIBs with 0.05 M and 1.0 M electrolytes were almost equivalent when tested at 25 °C and 60 °C. Moreover, when tested at 0 °C, KIBs with 0.05 M electrolyte could even deliver a higher specific capacity and initial coulombic efficiency than those with 1.0 M electrolyte. The formation of a KF inorganic component in the solid electrolyte interphase layer for this ultralow-concentration electrolyte could facilitate the transfer of K+ ions and favor electrode stability. This work sheds light on the development of ultralow-concentration electrolytes for rechargeable alkali-metal-ion batteries. [ABSTRACT FROM AUTHOR]

Vertical flow assay (VFA) is an effective point-of-care (POC) diagnostic tool for widespread application. Nevertheless, the lack of multi-target detection and multi-signal readout capability still remains a challenge. Herein, a brand new VFA scheme for multi-target saliva detection based on electronic tags was proposed, where AlGaN/GaN HEMT sensors modified with different bio-receptors as electronic tags endowed the VFA with multi-target detection capability. In addition, the use of electronic tags instead of optical tags allowed the VFA to simultaneously carry out direct multi-target readouts, which ensure effective POC diagnostics for saliva analysis. Moreover, by integrating a hydrophilically optimized micro-sieve, impurities like sticky filaments, epidermal cells and other large-scale charged particles in saliva were effectively screened, which enabled the direct detection of saliva using AlGaN/GaN HEMT sensors. Glucose, urea, and cortisol were selected to verify the feasibility of the multi-target e-VFA scheme, and the results showed that the limit of detection (LOD) was as low as 100 aM. The linear response was demonstrated in the dynamic range of 100 aM to 100 μM, and the specificity, long-term stability and validity of the actual saliva test were also verified. These results demonstrated that the as-proposed e-VFA has potential for application in saliva detection for simultaneous multi-target detection, and it is expected to achieve the real-time detection of more biological targets in saliva. [ABSTRACT FROM AUTHOR]

A new Co4-added polyoxometalate (CoAP) Cs4[(Co(H2O)5)2{(μ2-Co(H2O)4)2Co4(H2O)2(B-α-GeW9O34)2}]·6H2O (1) has been made using a lacunary directing strategy under hydrothermal conditions. Single-crystal X-ray diffraction analysis demonstrated that 1 is a one-dimensional (1D) chain, in which CoAP is linked by cobalt-oxygen octahedra to form a 1D structure with excellent chemical stability. The visible light-driven H2 evolution test demonstrated that 1 has high activity, with an H2 evolution rate of 1485.95 μmol h−1 g−1. PXRD and FT-IR tests demonstrated that compound 1 exhibits excellent heterogeneous catalytic stability. [ABSTRACT FROM AUTHOR]

2-(2-Methoxyethoxy)ethanol (MEEA) can cause DNA damage and teratogenesis, and the biomarker of MEEA is 2-(2-methoxyethoxy)acetic acid (MEAA). Therefore, portable and accurate monitoring of MEAA has far-reaching significance to ensure human health. In this work, a series of isometric three-dimensional (3D) lanthanide metal–organic frameworks (Ln-MOFs) {[Ln0.5(L)(H2O)]·1.5H2O}n (1-Ln, Ln = Eu, Tb, EuxTb1−x) were synthesized by using 1-(4-carboxyphenyl)-1H-pyrazole-4 carboxylic acid (H2L) and Ln3+. 1-Eu showed excellent sensing performance for MEAA with ultra-low detection limit (0.39 μM) and fast response time (within 1 min). To enhance the practicability of 1-Eu, three visual detection strategies of MEAA were provided. The polytetrafluoroethylene (PTFE) fluorescence film (Film@1-Eu) had a detection limit as low as the ppm level, and the fluorescence test paper achieved quantitative MEAA detection by combining with a smartphone sensing platform. In addition, a portable intelligent logic detector based on 1-Eu was designed by introducing a logic gate strategy for the real-time detection of MEAA. Notably, a Ln-MOF texture code with a high encryption algorithm and information density was designed for anti-counterfeiting labels on merchandise, utilizing the distinctive tuneable emission characteristic of 1-Ln. This study not only achieved the first visual detection of MEEA but also provided novel insights for the design of anti-counterfeiting materials. [ABSTRACT FROM AUTHOR]

Two structurally new Lindqvist hexaniobate-templated silver thiolate clusters, [Nb6O19@Ag45(iPrS)23(CH3COO)14] (Ag45) and (H3O)4[Nb6O19@Ag41KS2.5O2(H2O)7.5(iPrS)24(CH3COO)5] (Ag41), were synthesized using a facile one-pot solvothermal approach. Single crystal X-ray diffraction analyses revealed the presence of a classical Lindqvist-type [Nb6O19]8− anion template, with iPrS− and CH3COO− surface-protecting ligands in both silver clusters, which can further form two-dimensional Ag45 assembly and one-dimensional Ag41 chain packing structures. Both Ag45 and Ag41 clusters exhibited intriguing photothermal conversion properties and temperature-dependent emission behavior. [ABSTRACT FROM AUTHOR]

A quinoline-based covalent organic framework (N^N)-Q-COF was constructed with chemically stable networks and (N^N)-sites. Its coordination bond with Ir(C^N)2(N^N) units generated new entities with exciting photophysical properties; particularly, the incorporation of a coumarin ligand greatly elevated its properties to a higher level. The further anchoring of NiCl2 produced structures merging both photoredox and organometallic catalysts, resulting in excellent photocatalytic activities in C–S and C–N cross-coupling synthesis. The organic integration of Ir(C^N)2(N^N), NiCl2, and COFs and the advantages of COF networks were responsible for this transcendent dual catalysis. The chemical stability of Q-COFs and the coordination anchoring of Ir(C^N)2(N^N) and NiCl2 enabled its recycling and reuse with no reduction in catalytic performance. [ABSTRACT FROM AUTHOR]

In recent years, substantial progress has been made in improving the power conversion efficiency of perovskite solar cells (PSCs). However, persistent defects continue to impede their further advancement. Although ionic liquids (ILs) have been extensively utilized for perovskite defect passivation, their application, particularly in two-step methods, remains limited. In this study, we introduced formamidine acetate (FAAc) as a liquid additive, incorporated into the PbI2 precursor solution to finely regulate perovskite crystal growth. Utilizing a two-step method, we meticulously investigated the interaction of FAAc with perovskite components, laying the groundwork for effective defect passivation. Our systematic exploration delved into the nuanced influence of ILs on perovskite solar cells, including thin film morphology, optical properties, defect density, and overall device performance. Importantly, ILs facilitated the conversion of PbI2 into a perovskite material while reducing residual PbI2 during the perovskite crystallization process, thereby significantly improving the performance of PSCs, including device stability. Though defect passivation during perovskite formation facilitated the conversion of PbI2 and the modulation of thin film morphology, the photoelectric conversion efficiency of the treated PSCs approached an impressive 24.41%. Even after undergoing 2000 hours of aging in dry air, the efficiency remained at above 96% of the initial level. This research marks a pivotal step forward in the realm of PSCs. Our findings not only showcase the potential of ionic liquids in the two-step preparation of PSCs but also highlight their pivotal role in enhancing the efficiency and stability. [ABSTRACT FROM AUTHOR]

Cortisol hormone imbalances can be detected through non-invasive sweat monitoring using field-effect transistor (FET) biosensors, which provide rapid and sensitive detection. However, challenges like skin compatibility and integration with sweat collection have hindered FET biosensors as wearable sensing platforms. In this study, we present an integrated wearable sticker for real-time cortisol detection based on an extended-gate AlGaN/GaN high electron mobility transistor (HEMT) combined with a soft bottom substrate and flexible channel for sweat collection. The developed devices exhibit excellent linearity (R2 = 0.990) and a high sensitivity of 1.245 μA dec−1 for cortisol sensing from 1 nM to 100 μM in high-ionic-strength solution, with successful cortisol detection demonstrated using authentic human sweat samples. Additionally, the chip's microminiature design effectively reduces bending impact during the wearable process of traditional soft binding sweat sensors. The extendedgate structure design of the HEMT chip enhances both width-to-length ratio and active sensing area, resulting in an exceptionally low detection limit of 100 fM. Futhermore, due to GaN material's inherent stability, this device exhibits long-term stability with sustained performance within a certain attenuation range even after 60 days. These stickers possess small, lightweight, and portable features that enable real-time cortisol detection within 5 minutes through direct sweat collection. The application of this technology holds great potential in the field of personal health management, facilitating users to conveniently monitor their mental and physical conditions. [ABSTRACT FROM AUTHOR]

Anderson-type polyoxometalates have exhibited remarkable catalytic capabilities in a wide range of reactions. This discourse delves into the distinct categories of Anderson POMs and their respective catalytic reactions, which are examined in separate segments. These encompass the straightforward {XMo6} POMs, the organic grafting {XMo6} POMs, and the integration of POMs into POM cluster organic frameworks. It is important to highlight that specific catalytic functionalities can solely be accomplished via the utilization of Anderson-type POMs, thus emphasizing their indispensable role in future explorations. [ABSTRACT FROM AUTHOR]

A cage-like MOF has demonstrated tremendous potential in gas selective adsorption and CO2 catalysis due to its distinctive structural features. Accordingly, a novel cage-like MOF 1 was synthesized using the biphenyl tricarboxylic acid ligand, (1,1′-biphenyl)-2,4,6-tricarboxylic acid (H3L), and Zn(II) via a solvothermal reaction. 1 exhibited a porous three-dimensional framework formed by interconnected dodecahedron (5.2 Å) and octahedron (4.7 Å) cages, which was based on an interesting 13-connected fcu topology. Significantly, 1a has excellent adsorption properties for C2H2 and CO2 and selective separation performance for C2H2/CO2, C2H2/CH4, and CO2/CH4. Moreover, under the action of the Lewis acid sites, 1a also shows highly efficient and recyclable catalytic properties for the reaction of CO2 with various epoxides. [ABSTRACT FROM AUTHOR]

Selective hydrogenolysis of abundant C–O bonds of β-O-4 linkages in natural lignin or lignin models has been considered as a key strategy for the generation of value-added organic chemicals. Herein, we report a mild, efficient, and selective photocatalytic strategy for hydrogenolytic cleavage of lignin β-O-4 models by using Ni-containing polyoxometalate (POM) catalysts and CdS quantum dots. Upon blue LED light irradiation, the present photocatalytic system can effectively transform various lignin β-O-4 models to the corresponding hydrogenolysis products (phenols and ketones) with >95% conversion and >93% product selectivity. A tentative photocatalytic mechanism is proposed based on various experimental and spectroscopic analyses. The facile strategy presented in our work could be extended to the photocatalytic preparation of various value-added chemicals from natural biomass or other biomass derivatives in the near future. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have emerged as significant candidates for visible-light photocatalysis due to their ability to regulate performance which is achieved through the careful selection of building modules, framework conjugation, and post-modification. This report focused on the efficient transformation of an imine-linked I-COF into a π-conjugated quinoline-based Q-COF, which enhanced both the chemical stability and conjugation of the network. By methylating the pyridyl groups in the Q-COF, an N+-COF was obtained. Subsequently, the Ru(N^N)3-photosensitizer ([Ru(dcbpy)3]4−) was incorporated into the channels of the cationic N+-COF through electrostatic interactions, resulting in the formation of [Ru(dcbpy)3]4−⊂N+-COF. This composite exhibited exceptional photocatalytic activity, demonstrating high yields and selectivity in the oxidation of sulfides or amines to their respective products. [ABSTRACT FROM AUTHOR]

Three new aluminoborates (ABOs) KCs[Al{B5O9(OH)}{BO(OH)2} (1), K0.5Cs[Al{B5O10}1/2{BO2(OH)}] (2), and Cs1.5[Al{B5O10}1/2{BO2(OH)}] (3) have been made under solvothermal conditions. 1 features a 1D tube constructed by the alternation of [B5O9(OH)]4− clusters and AlO4 units, onto which the [BO(OH)2]− triangles are grafted. To further construct higher dimensional structures based on the structure 1, solvents were adjusted for high basicity, resulting in the formations of the 3D ABO frameworks 2 and 3. 2 and 3 are isostructural and built from [B5O10]5− clusters, AlO4 tetrahedra and [BO2(OH)]2− triangles, in which [B5O10]5− clusters are bridged by AlO4 tetrahedra to produce a 2D ABO layer with 14-membered ring (MR) windows, and the [BO2(OH)]2− triangles act as the linkers to bridge the adjacent ABO layers to form 3D ABO frameworks containing eight types of channels. UV-vis diffuse reflectance spectra indicate that 1, 2, and 3 have potential applications in deep ultraviolet (DUV) regions. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution using metal–organic frameworks (MOFs) has tremendous potential for relieving the environmental and energy crises. Herein, a three dimensional zinc–organic framework (1) was successfully synthesized based on 1,3,6,8-tetra(pyridin-4-yl)pyrene (TTPy). Compound 1 exhibited a good light absorption with an absorption edge at approximately 600 nm. Importantly, 1 can maintain the crystalline state in TEOA solution, and even remain stable in a 5 M NaOH aqueous solution, suggesting 1 has high alkali resistance. Photocatalytic results indicate that 1 as a photocatalyst has high activity for H2 production with TEOA as a sacrificial agent, and the H2 evolution rate is 315.06 μmol g−1 h−1 even under long reaction time (35 h) without the addition of photosensitizers. Mechanism explorations suggest that the π–π interaction between parallel ligands, high alkali-stability and light-absorbing ability, good photocurrent response, and suitable band gap of compound 1 are responsible for the high photocatalytic activity. Density functional theory (DFT) calculations further reveal that the experimental energy gap of 1 is well consistent with the theoretical bandgap. This work provides a new strategy for the exploitation of alkali-stable MOFs in the photocatalysis field. [ABSTRACT FROM AUTHOR]

The chemistry of polypyridyl Ru(II) and cyclometalated Ir(III) derivatives provides long-lasting interest to researchers due to the inherent advantage of their triplet states in a variety of photoactivities. The introduction of Ru(N^N)3 and Ir(C^N)2(X^N) modules into well-defined architectures extends the research areas of both photoactive metal complexes and network chemistry, generating a lot of new opportunities with interesting structural aesthetics and profound functional possibilities. The rapid development of research in integrating Ru(II) or Ir(III) metallotecons into the architectures has been apparent in recent years which makes this a fascinating subject for reviewing. This review focuses on the design and syntheses of Ru(N^N)3 and Ir(C^N)2(X^N) functionalized architectures of metal–organic frameworks (MOFs), covalent–organic frameworks (COFs), metallasupramolecules, organic supramolecules and supramolecular organic frameworks (SOFs). Furthermore, the photocatalytic applications including the hydrogen evolution reaction (HER), carbon dioxide reduction reaction (CO2RR), photocatalytic oxidation and photoredox catalysis of organic transformation are also presented. [ABSTRACT FROM AUTHOR]

85Kr is a major radioactive byproduct released during nuclear fuel reprocessing and an important atmospheric indicator for nuclear safety and environmental monitoring. In this work, we report on online monitoring of atmospheric 85Kr activities with time resolution of 1.5 hours. An automated Kr purification system and an atom trap based 85Kr measurement system work synchronously in the experiment. The Kr purification system features temperature-controlled cryogenic distillation and gas chromatography, which allows direct sampling of ambient air and continuous operation. The separated Kr is fed into an atom trap capable of measuring the abundance of 85Kr with micro-L size Kr samples. The sample consumption is 3 L STP of air per measurement with a 1.5 hour processing time. Compared to the conventional monitoring method based on proportional counting, both the measurement time and sample size (10 m3 and 1 week) are reduced by several orders of magnitude. The 85Kr analysis technology demonstrated in this work allows analysis of atmospheric 85Kr activities with hourly resolution, enabling applications such as online monitoring of nuclear fuel reprocessing plants and tracing of atmospheric circulation patterns. [ABSTRACT FROM AUTHOR]

A new two-dimensional {Cu6}-added polyoxometalate cluster–organic framework (Cu-POMCOF) was prepared by a hydrothermal method from lacunary polyoxoanions and was applied as a solid support for immobilizing MP-11 and Cyt c. The biocomposite complex exhibits higher stability and catalytic activity than the original free enzyme. [ABSTRACT FROM AUTHOR]

Implementing the dual-ligand strategy, a microporous Zn-based MOF 1 with nitro and amino groups was effectively produced. The activated interconnected pores of 1 exhibited high C2H2 uptake capacity and preferential adsorption behaviour for C2H2 over CO2, as identified by the experiments and simulations. This work provides a new approach for designing and synthesizing the MOFs with desired structures and properties by optimizing their pore environment via the dual-ligand strategy. [ABSTRACT FROM AUTHOR]

The efficient and selective cleavage of the β-O-4 linkage under mild conditions represents a promising strategy to convert lignocellulose to value-added aromatic chemicals. In this work, a recoverable polyoxometalate-ionic liquid (POM-IL) catalyst has been successfully constructed by reacting H5PMo10V2O40 (HPMoV) polyoxoacids with 1-methyl-3-(4-sulfobutyl)-1H-imidazolium (BMIM-SO3) zwitterions. Such a POM-IL catalyst can selectively and effectively convert various β-O-4 lignin models into aromatic acids and phenols under mild homogeneous conditions. Addition of ethyl acetate to the homogeneous post-reaction solution allows the easy recovery of the POM-IL catalyst for successive five recycling tests with high robustness. The dominant catalytic pathway was elucidated by a series of mechanistic studies. [ABSTRACT FROM AUTHOR]

A novel Zr-added trimer, [H2N(CH3)2]10H14[(Zr2P2W16O61)3]·7H2O (1), has been made under hydrothermal conditions, and contains the highest number of Zr centers in known Dawson-type poly(POM)s. A remarkable feature of this study is the first discovery of a new type of divacant [α-5,10-P2W16O60]14− fragment, which assembles with Zr4+ ions to form a cyclic trimer. Furthermore, 1 as a heterogeneous catalyst exhibits high activity for the selective oxidative degradation of a sulfur mustard simulant CEES. [ABSTRACT FROM AUTHOR]

Two three-dimensional (3D) porous-layered borates, Na0.5K2.5[AlB7O13(OH)]·H2O (1) and NaKCs[GaB7O13(OH)]·1.5H2O (2), have been obtained under solvothermal conditions. Compound 1 crystallizes in the triclinic space group P1¯, while 2 crystallizes in the monoclinic space group P21/n. Compounds 1 and 2 contain similar units of B7O13(OH) and AlO4/GaO4; the strict alternations of B7O13(OH) clusters and AlO4/GaO4 resulted in 3D open-framework layers with 8-R and 13-R channels along different directions. The shapes and orientations of the channels of 1 and 2 are different due to their different space groups. It's interesting to note that three different alkali metal ions (Na+, K+, and Cs+) are found in different positions in 2. UV-vis diffuse reflectance analysis indicates that both compounds show a wide transparency range with a short-wavelength absorption edge below 190 nm. [ABSTRACT FROM AUTHOR]

The search for laser-ignitable energetic materials catering to the safety and accuracy requirements in military and civilian affairs is an important yet challenging task. In this work, non-explosive and stable nitro bearing ligands of 3,5-dinitro-4-chlorobenzoic acid (HDNB-Cl) and 3,5-dinitro-4-hydroxybenzoic acid (HDNB-OH) have been adopted as energetic modules and organic building units to assemble with copper ions to construct energetic coordination complexes. The d–d transition introduced by Cu2+ endows the as-synthesized compounds to display remarkable absorptions of NIR light, and thus achieve efficient photothermal conversions upon irradiation by an 808 nm laser. As a result, the DNB-Cl based complexes can be laser-ignited and strong deflagration has been observed. The satisfactory thermal stability and tolerance toward friction and electrostatic discharge make them good candidates as laser-ignitable energetic materials. Unlike the conventional energetic materials based on nitrogen-rich organics (e.g., azido, furazan, and heterocyclic compounds), this work reveals that the easily functionalized nitro-bearing carboxylate ligand is an alternative energy module for assembling stable energetic complexes, and the coordination interaction-induced photothermal conversion would be an efficient strategy to achieve laser ignition for the resultant energetic compounds. [ABSTRACT FROM AUTHOR]

The MgH2–LiH composites with different composition ratios were prepared by different ball milling times, and the hydrogen generation performances of the composites were investigated and compared. X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy techniques were adopted to elucidate the performance improvement mechanisms. The results show that the hydrogen generation yield and kinetics can be improved with the increase of LiH content significantly. For the 7MgH2–3LiH and 1MgH2–1LiH, with the increase of the ball milling time, the hydrogen yield increases firstly, and then decreases, but the kinetics almost do not change. This may be caused by the change of particle size of the composites after ball milling. However, for the 9MgH2–1LiH, the hydrogen yield increases with ball milling time but the kinetics decrease gradually. This may be due to the gradual movement of LiH from the surface to the interior of MgH2 and to the covering of MgH2 after ball milling. [ABSTRACT FROM AUTHOR]

Developing efficient adsorbent materials towards energy gas purification, e.g. CO2 removal from natural gas or hydrocarbon separation, is an important but extremely challenging task. Herein, taking advantage of a cationic bipyridinium ligand in competition with a multicarboxylate ligand for binding with metal ions, a porous material with open carboxylate oxygen atoms exposed on the pore surface has been demonstrated as an efficient adsorbent for gas separation. The polar environment arising from the cationic pyridinium moiety and the negative carboxylate group endows the title compound with selective affinity to CO2 over CH4. Moreover, the rich open O donor sites on the channel surface enable the resultant coordination polymer to selectively adsorb C2H2 over C2H4 through H-bonding interactions. The separation mechanism has been revealed by theoretical studies. This work provides a specific guidance for the design of applicable porous materials toward energy resource purification. [ABSTRACT FROM AUTHOR]

Two layered galloborates (GBOs), Na3GaB4O9 (1) and Na5Ga[B7O12(OH)]2·2B(OH)3 (2), have been solvothermally made. 1 exhibits an unprecedented layer built by GaO4 tetrahedra and B4O9 clusters. 2 was made by raising the ratio of B/Ga and the reaction temperature of 1, featuring a 2D acentric layer built by GaO4 groups and B7O13(OH) clusters. 2 shows the highest second-harmonic generation (SHG) response of 4.6 times that of KDP (KH2PO4) among main group metal borates (MBOs). [ABSTRACT FROM AUTHOR]

A 4p–4f cluster incorporated polyoxometalate (POM), namely, H18{[(H4pic)4Eu10Se13O28(H2O)12](α-GeW9O34)4·40H2O (1-Eu, H4pic = isonicotinic acid), has been first synthesized and characterized. 1-Eu features an interesting four-shell structure, representing the largest Se-4f cluster incorporated POM known to date. Besides, 1-Eu exhibits excellent Lewis acid–base catalytic activity and reusablity in catalyzing the gram-scale dehydration condensation reaction of hydrazines and 1,3-diketones to synthesize polysubstituted pyrazoles. [ABSTRACT FROM AUTHOR]

Using the photosensitized Ru(N∧N∧N)2-metalloligand, a series of Ce frameworks were synthesized. The incorporation of the visible-light-responsive Ru(N∧N∧N)2-unit endows the Ce frameworks with photocatalytic activities in both sulfide oxidation and hydrogen production. The doping of Zr and particularly the oxidation state of Ce has great influence on the photocatalytic properties of the Ce frameworks. [ABSTRACT FROM AUTHOR]

Two new B3O7 cluster-based borates, [B6O9(OH)2]·H2dap (1, dap = 1,2-diaminopropane) and Li0.5Ca0.5[B3O5][BO(OH)2]0.5 (2), were solvothermally synthesized using different organic and inorganic templates, respectively. In 1, two different B3O7 clusters interconnect to construct a rare 2D fluctuant layer with 11-MR unclosed channels. Templating [H21,2dap]2+ located in the interlayers stabilizes the layers through H-bonds. 2 features an acentric 3D open framework with 17-MR large channels built by 4-connected B3O7 clusters. Guest Li-BO(OH)2-Ca 1D chains intercalate in the 17-MR channels, directing the formation of the 3D open framework through host–guest symmetry and charge matching. 2 is a phase-matchable nonlinear optical (NLO) material with a second-harmonic generation (SHG) response ∼1.6 times that of KDP (KH2PO4). UV-vis absorption spectra reveal that 1 and 2 have short cut-off edges of 205 and 213 nm, respectively, indicating that 1 is a wide-band semiconductor and 2 is a UV NLO material. [ABSTRACT FROM AUTHOR]

A novel two-dimensional coordination polymer with a negatively charged framework named {[(CH3)2NH2][Zn2(L)2]·DMF}n (1) was solvothermally synthesized via the assembly of Zn(II) ions with the organic ligand H3L (2-(3,5-dicarboxylphenyl)-6-carboxyl-benzimidazole). 1 was characterized by IR spectroscopy, thermogravimetry, single-crystal, and powder X-ray diffraction methods. 1 possesses a 1D rectangle channel decorated by abundant uncoordinated imidazole N atoms and carboxylate O atoms, and is a better CO2 adsorbent and promising CO2/CH4 selective material, suggesting potential application in gas separation. Moreover, 1 can also serve as a multi-responsive sensing material for detecting nitrobenzene (NB) and Cr2O72−via a luminescence quenching effect with a low detection limit, and the mechanisms of the quenching effect and sensing properties of 1 are discussed in detail. [ABSTRACT FROM AUTHOR]

Covalent organic polymers (COPs) are designable porous organic polymers that have attracted increasing research interest and have developed as electrode materials for supercapacitors. By using an easy synthesis method, a novel phosphazene-anthraquinone-based covalent organic polymer (HD-1) was successfully designed and synthesized through a polymerization reaction between hexachlorocyclotriphosphazene (HCCP) and 2,6-diaminoanthraquinone (DAAQ) in dimethylsulphoxide (DMSO). Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption–desorption analysis, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometr (EDX) and thermogravimetric analysis (TGA) were used to characterize the structure and properties of HD-1. The specific surface was calculated as 249.2 m2 g−1. The specific capacitance of HD-1 was 125.6 F g−1 at a current density of 0.5 A g−1 in a 6.0 M potassium hydroxide electrolyte. After 20 000 GCD cycles, the specific capacitance retention was about 92.8% of its initial capacitance. [ABSTRACT FROM AUTHOR]

Five new rubidium borates, namely Na1/3Rb5/3[B4O5(OH)4] (1), Rb4[B12O18(OH)4] (2), Rb2Ba[B12O18(OH)4] (3), Rb2[B5O8(OH)] (4) and NaRb0.5[B6O10]·0.5H3O (5) have been synthesized under solvothermal conditions. Compound 1 features a 0D structure composed of [B4O5(OH)4]2− clusters. After changing the metal salt, new cyclic [B12O20(OH)4]8− clusters in 2 and 3 are formed, resulting in 1D chains. Such a chain structure is first discovered in dodecaborates. By tuning the reaction temperature and pH of the reaction media, compound 4 with a 4-connected 2D oxoboron layer constructed from partially protonated [B5O10(OH)]6− and compound 5 with a 6-connected 3D framework constructed from [B6O13]8− clusters are successfully isolated. Since compounds 1 and 4 crystallize in the non-centrosymmetric (NCS) space group, second harmonic generation (SHG) measurements and dipole moment calculations have been carried out. The SHG response of 4 is 2.0 times that of KH2PO4 (KDP), which is higher than those of related analogues. [ABSTRACT FROM AUTHOR]