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Development of multipurpose adsorbents for highly efficient separation of acetylene (C2H2) from carbon dioxide (CO2) and ethylene (C2H4) is of great importance but highly challenging due to their very similar sizes and physical properties. While many adsorbents have been developed to show efficient separation of either C2H2/CO2 or C2H2/C2H4, multipurpose materials with high selectivities for both gas mixtures are elusive. Herein, we developed an anion-pillared metalloporphyrin SIFSIX material (termed ZJUT-6) as a multipurpose adsorbent for highly efficient separation of C2H2 from CO2 and C2H4. Unlike routine SIFSIX materials with strong fluorine binding sites for gas separations, the use of metalloporphyrin as a building block enables ZJUT-6a to create unique sandwich-like binding sites with dual open metal sites, which can more optimally interact with the C2H2 molecule over CO2 and C2H4. ZJUT-6a thus exhibits large C2H2 capture capacities and simultaneous high C2H2/CO2 (8.9) and C2H2/C2H4 (12.2) selectivities under ambient conditions. Theoretical simulations reveal that the oppositely adjacent copper(II) centers and porphyrin groups from metalloporphyrin ligands in ZJUT-6a can construct a sandwich-type adsorption site to offer dually stronger interactions with C2H2 over CO2 and C2H4. Dynamic breakthrough experiments on ZJUT-6a demonstrate its highly efficient separation of C2H2 from actual C2H2/CO2 (50/50) and C2H2/C2H4 (1/99) gas mixtures. [ABSTRACT FROM AUTHOR]

Microporous hydrogen-bonded organic frameworks (HOFs) have been considered promising materials for ethane/ethylene (C2H6/C2H4) separation owing to their native nonpolar pores. However, the absence of functional binding sites on nonpolar pore surfaces commonly limits their separation performance. Herein, we report and construct a novel HOF material (termed as ZJU-HOF-60a) by incorporating electron-rich alkynyl groups into its pore surfaces to achieve highly efficient C2H6/C2H4 separation. The incorporated alkynyl groups not only serve as functional binding sites to provide multiple supramolecular interactions with the C2H6 molecule, but also do not participate in the formation of any hydrogen bonds in order to obtain the desired HOF framework. Alkynyl-functionalized ZJU-HOF-60a thus exhibits both a top-tier C2H6 uptake capacity of 3.79 mmol g−1 and C2H6/C2H4 uptake ratio of 1.58 at 296 K and 1 bar, surpassing most of the previously reported C2H6-selective HOFs. Theoretical calculations indicate that the incorporated alkynyl groups combined with the surrounding carboxylic groups provide stronger and more number of C–H⋯π and C–H⋯O interactions to bind with C2H6 over C2H4, thus accounting for efficient C2H6/C2H4 separation. The actual separation performance of ZJU-HOF-60a was confirmed using breakthrough experiments for 50/50 (v/v) C2H6/C2H4 gas mixtures, affording a highly pure C2H4 productivity of 7.8 L kg−1 under ambient conditions. [ABSTRACT FROM AUTHOR]

Metal–organic compound derived composites are promising multi-functional materials owing to their adjustable composition, tunable shape and porous structure. However, it is very attractive but challenging to design light and thin composites derived from metal–organic compounds with broad and strong electromagnetic-wave absorption (EWA). Herein, we designed and synthesized a series of urchin-like porous structures (CoO/C-450, CoO/C-500, Co/C-550 and Co/C-600) with wideband and strong EWA performance through heat treatments on a Co-based metal–organic precursor at different temperatures. The three-dimensional urchin-like porous structure can not only promote electromagnetic wave propagation and attenuation, but also enhance surface polarization relaxation. As a result, this kind of urchin-like morphology leads to exceptional interface polarization loss and impedance matching, affording a wide absorption bandwidth exceeding 7 GHz over X and Ku bands. Among these materials, Co/C-550 demonstrates an outstanding performance, affording an effective absorption bandwidth of 7.92 GHz with a low thickness of 2.5 mm and a minimum reflection loss of −51.2 dB. The remarkable EWA performance was mainly attributed to the synergistic effect of the urchin-like morphology, porous structure, and dielectric and magnetic losses. This work provides some guidance for the design of light and thin electromagnetic wave absorption materials with a wide absorption bandwidth. [ABSTRACT FROM AUTHOR]

Two oxygenated ergostane-type steroids including one new compound, 3β-hydroxy-5α,6β-methoxyergosta-7,22-dien-15-one (1) along with a known analogue ergosta-6,22-dien-3β,5α,8α-triol (2) were isolated from the crude extracts of the marine sponge-derived fungus Aspergillus sp. Their structures were elucidated on the basis of combined NMR and MS spectroscopic methods. Compound 1 was a marine ergostane-type steroid with two methoxy groups at C-5 and C-6, respectively. These oxygenated ergostane-type steroids were evaluated for their antibacterial activities against human or aquatic pathogens. Among them, compound 1 exhibited antibacterial activity against Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Flexible humidity sensors with high sensitivity, fast response time, and outstanding reliability have the potential to revolutionize electronic skin, healthcare, and non-contact sensing. In this study, we employed a straightforward nanocluster deposition technique to fabricate a resistive humidity sensor on a flexible substrate, using molybdenum oxide nanoparticles (MoOx NPs). We systematically evaluated the humidity-sensing behaviors of the MoOx NP film-based sensor and found that it exhibited exceptional sensing capabilities. Specifically, the sensor demonstrated high sensitivity (18.2 near zero humidity), a fast response/recovery time (1.7/2.2 s), and a wide relative humidity (RH) detection range (0–95%). The MoOx NP film, with its closely spaced granular nanostructure and high NP packing density, exhibited insensitivity to mechanical deformation, small hysteresis, good repeatability, and excellent stability. We also observed that the device exhibited distinct sensing kinetics in the range of high and low RH. Specifically, for RH > 43%, the response time showed a linear prolongation with increased RH. This behavior was attributed to two factors: the higher physical adsorption energy of H2O molecules and a multilayer physical adsorption process. In terms of applications, our sensor can be easily attached to a mask and has the potential to monitor human respiration owing to its high sensing performance. Additionally, the sensor was capable of dynamically tracking RH changes surrounding human skin, enabling a non-contact sensing capability. More significantly, we tested an integrated sensor array for its ability to detect moisture distribution in the external environment, demonstrating the potential of our sensor for contactless human–machine interaction. We believe that this innovation is particularly valuable during the COVID-19 epidemic, where cross-infection may be averted by the extensive use of contactless sensing. Overall, our findings demonstrate the tremendous potential of MoOx NP-based humidity sensors for a variety of applications, including healthcare, electronic skin, and non-contact sensing. [ABSTRACT FROM AUTHOR]

Developing porous materials for C3H6/C3H8 separation faces the challenge of merging excellent separation performance with high stability and easy scalability of synthesis. Herein, we report a robust Hofmann clathrate material (ZJU‐75a), featuring high‐density strong binding sites to achieve all the above requirements. ZJU‐75a adsorbs large amount of C3H6 with a record high storage density of 0.818 g mL−1, and concurrently shows high C3H6/C3H8 selectivity (54.2) at 296 K and 1 bar. Single‐crystal structure analysis unveil that the high‐density binding sites in ZJU‐75a not only provide much stronger interactions with C3H6 but also enable the dense packing of C3H6. Breakthrough experiments on gas mixtures afford both high separation factor of 14.7 and large C3H6 uptake (2.79 mmol g−1). This material is highly stable and can be easily produced at kilogram‐scale using a green synthesis method, making it as a benchmark material to address major challenges for industrial C3H6/C3H8 separation. [ABSTRACT FROM AUTHOR]

Developing porous materials to overcome the trade‐off between adsorption capacity and selectivity for C2H2/CO2 separation remains a challenge. Herein, we report a stable HKUST‐1‐like MOF (ZJU‐50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2H2 storage and selectivity. ZJU‐50a exhibits one of the highest C2H2 storage capacity (192 cm3 g−1) and concurrently high C2H2/CO2 selectivity (12) at 298 K and 1 bar. Single‐crystal X‐ray diffraction studies on gas‐loaded ZJU‐50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2H2 molecule but not CO2 to result in both high C2H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2H2/CO2 mixtures, providing a high C2H2 recovery capacity of 84.2 L kg−1 with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade‐off for this separation. [ABSTRACT FROM AUTHOR]

Porous materials for C2H2/CO2 separation mostly suffer from high regeneration energy, poor stability, or high cost that largely dampen their industrial implementation. A desired adsorbent should have an optimal balance between excellent separation performance, high stability, and low cost. We herein report a stable, low‐cost, and easily scaled‐up aluminum MOF (CAU‐10‐H) for highly efficient C2H2/CO2 separation. The suitable pore confinement in CAU‐10‐H can not only provide multipoint binding interactions with C2H2 but also enable the dense packing of C2H2 inside the pores. This material exhibits one of the highest C2H2 storage densities of 392 g L−1 and highly selective adsorption of C2H2 over CO2 at ambient conditions, achieved by a low C2H2 adsorption enthalpy (27 kJ mol−1). Breakthrough experiments confirm its exceptional separation performance for C2H2/CO2 mixtures, affording both large C2H2 uptake of 3.3 mmol g−1 and high separation factor of 3.4. CAU‐10‐H achieves the benchmark balance between separation performance, stability, and cost for C2H2/CO2 separation. [ABSTRACT FROM AUTHOR]