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Solid adsorbents that simultaneously have high selectivity and uptake capacity are highly promising as alternatives to conventional cryogenic distillation of propene/propane (C3H6/C3H8) separation. Coordinatively unsaturated metal sites (CUS) plays a vital role in selective adsorption of olefins over paraffins. Ultrathin poly (triazine imide) (PTI) nanosheets can reach rapid gas adsorption equilibrium, due to its large surface-to-volume ratio. In this work, combining the advantages of the CUS and the PTI nanosheets, Li CUSs were introduced into the PTI nanosheets for C3H6/C3H8 separation. Density functional theory (DFT) calculations demonstrated the thermodynamic feasibility of incorporating Li CUSs into the PTI nanosheets. These highly exposed Li CUSs were predicted to have a higher adsorption affinity toward C3H6 than C3H8. Using the DFT-derived force field parameters, we further performed grand canonical Monte Carlo (GCMC) simulations to investigate C3H6/C3H8 adsorption on the Li−PTI complexes slit pore model with different pore widths (H). We found that the Li−PTI complexes display considerable C3H6/C3H8 selectivity (4.2∼7.9) under relevant conditions. Moreover, the Li−PTI complexes slit pore have large C3H6 working capacities (1.5∼4.0 mmol g-1), superior to those calculated for the most of adsorbent materials that have been reported. The Li−PTI complexes with slit pore architecture show potential as C3H6/C3H8 separation materials.

Separation of acetylene from carbon dioxide remains a daunting challenge because of their very similar molecular sizes and physical properties. We herein report the first example of using copper(I)-alkynyl chemistry within an ultra-microporous MOF (CuI @UiO-66-(COOH)2 ) to achieve ultrahigh C2 H2 /CO2 separation selectivity. The anchored CuI ions on the pore surfaces can specifically and strongly interact with C2 H2 molecule through copper(I)-alkynyl π-complexation and thus rapidly adsorb large amount of C2 H2 at low-pressure region, while effectively reduce CO2 uptake due to the small pore sizes. This material thus exhibits the record high C2 H2 /CO2 selectivity of 185 at ambient conditions, significantly higher than the previous benchmark ZJU-74a (36.5) and ATC-Cu (53.6). Theoretical calculations reveal that the unique π-complexation between CuI and C2 H2 mainly contributes to the ultra-strong C2 H2 binding affinity and record selectivity. The exceptional separation performance was evidenced by breakthrough experiments for C2 H2 /CO2 gas mixtures. This work suggests a new perspective to functionalizing MOFs with copper(I)-alkynyl chemistry for highly selective separation of C2 H2 over CO2 .

This work obtained gel polymer electrolytes (GPEs) via in situ polymerization of methyl methacrylate (MMA) in the environment of lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) and N-methyl-N-propylpyrrolidinium bis(trifluoromethane sulfonyl)amide (Py13TFSI). The thermogravimetric analysis (TGA) and the differential scanning calorimeter (DSC) determined the non-isothermal decomposition of Py13TFSI/LiTFSI/PMMA polymer electrolyte for Li-ion battery. TGA, DSC, and the infrared graph analyzed thermodynamic properties, and the results showed the addition of Py13TFSI significantly improved the thermostability of electrolytes. Flynn-Wall-Ozawa (Ozawa), Kissinger-Akahira-Sunose (KAS), and Friedman methods applied for kinetics characteristics to activation energy (Ea) and pre-exponential factor (A). The Ea value from Ozawa and KAS methods was 208.478 kJ mol−1 and 207.423 kJ mol−1, respectively.

For the separation of ethane from ethylene, it remains challenging to target both high C2H6 adsorption and selectivity in a C2H6-selective material. Herein, we report a reversible solid-state transformation in a labile hydrogen-bonded organic framework to generate a new rod-packing desolvated framework (ZJU-HOF-1) with suitable cavity spaces and functional surfaces to optimally interact with C2H6. ZJU-HOF-1 thus exhibits simultaneously high C2H6 uptake (88 cm3 g-1) at 0.5 bar and 298 K) and C2H6/C2H4 selectivity (2.25), which are significantly higher than those of most top-performing materials. Theoretical calculations revealed that the cage-like cavities and functional sites synergistically ``match'' better with C2H6 to provide stronger multipoint interactions with C2H6 than C2H4. In combination with its high stability and ultralow water uptake, this material can efficiently capture C2H6 from 50/50 C2H6/C2H4 mixtures in ambient conditions under 60 providing a record polymer-grade C2H4 productivity of 0.98 mmol g-1.

Herein, an induced self-enhanced electrochemiluminescence (ECL) sensor with superior ECL performances was simply fabricated by just dropping the ECL reagent (tris(4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium (II) dichloride, Ru(dcbpy)3Cl2) and coreactant (nitrogen-doped carbon quantum dots, NCQDs) pair onto the surface of glassy carbon electrode. In this strategy, based on the carboxyl (–COOH) groups in Ru(dcbpy)32+ and oxygen, nitrogen-containing groups on NCQDs surface, an intermolecular hydrogen bonds-induced self-enhanced ECL composite was generated in the solid contact layer for the first time. Since Ru(dcbpy)32+ and NCQDs were co-existing in the same composite, the electron-transfer distance between them was shortened and the energy loss was decreased, thereby higher ECL efficiency was acquired. This working process greatly avoided the introduction of signal amplifier and simplified the experimental operation. On this basis, 17β-estradiol (E2) was selected as a target model to fabricate a self-enhanced ECL aptamer sensor for the investigation of its analytical performances. Resultantly, excellent detection properties of E2, including wider linear range of 1.0 × 10-14 − 1.0 × 10-6 mol L-1 and lower detection limit of 1.0 × 10-15 mol L-1 with superior selectivity, were successfully achieved. Finally, E2 spiked into milk powder was quantified to assess the practicability of this sensor. Prospectively, this strategy could be extensively applied for other analytes determination by adjusting the corresponding target aptamers.

Although considerable achievements have been realized in recent years with respect to the syntheses of metal-organic frameworks (MOFs), majority of the developed MOFs are in the form of polydisperse microcrystalline powders, which cause dustiness, abrasion, and clogging and decrease pressure when used in industrial applications. Monolithic MOFs overcome these drawbacks and exhibit various promising characteristics. In this review, we present the recent advances associated with monolithic MOFs based on metal centers and a brief outline of the most prominent examples. Furthermore, the challenges and prospects associated with monolithic MOFs in terms of large-scale production and engineering applicability are analyzed based on our knowledge to conclude this review.

The emergence of MoS2 nanopores has provided a new avenue for high performance DNA sequencing, which is critical for modern chemical/biological research and applications. Herein, molecular dynamics simulations were performed to design a conceptual device to sequence DNA with MoS2 nanopores of different structures (e.g., pore rim contained Mo atoms only, S atoms only, or both Mo and S atoms), where various unfolded single-stranded DNAs (ssDNAs) translocated through the nanopores driven by transmembrane bias; the sequence content was identified by the associating ionic current. All ssDNAs adsorbed onto the MoS2 surface and translocated through the nanopores by transmembrane electric field in a stepwise manner, where the pause between two permeation events was long enough for the DNA fragments in the nanopore to produce well-defined ionic blockage current to deduce the DNA’s base sequence. The transmembrane bias and DNA-MoS2 interaction could regulate the speed of the translocation process. Furthermore, the structure (atom constitution of the nanopore rim) of the nanopore considerably regulated both the translocate process and the ionic current. Thus, MoS2 nanopores could be employed to sequence DNA with the flexibility to regulate the translocation process and ionic current to yield the optimal sequencing performance.

The separation of ethylene (C2H4) from C2 hydrocarbons is considered as one of the most difficult and important processes in the petrochemical industry. Heat-driven cryogenic distillation is still widely used in the C2 hydrocarbons separation realms, which is an energy intensive process and takes up immense space. In response to a greener, more energy-efficient sustainable development, we successfully synthesized a multifunction microporous Mg-based MOF [Mg2(TCPE)(µ2-OH2)(DMA)2].solvents (NUM-9) with C2H6/C2H2 selectivity based on a physical adsorption mechanism, and with outstanding stability; especially, it is stable up to 500 °C under an air atmosphere. NUM-9a (activated NUM-9) shows good performances in the separation of C2H6/C2H2 from raw ethylene gases. In addition, its actual separation potential is also examined by LAST and dynamic column breakthrough experiments. GCMC calculation results indicate that the unique structure of NUM-9a is primarily conducive to the selective adsorption of C2H6 and C2H2. More importantly, compared with C2H4, NUM-9a prefers to selectively adsorb C2H6 and C2H2 simultaneously, which makes NUM-9a as a sorbent have the capacity to separate C2H4 from C2 hydrocarbon mixtures under mild conditions through a greener and energy-efficient separation strategy.

In response to the safety performance of liquid electrolytes in traditional lithium-ion batteries, we have prepared a new type of polymer electrolyte. In this paper, PVDF is used as the polymer electrolyte matrix, bio-based filler soybean protein isolate (SPI), and inorganic filler montmorillonite (MMT) as additional groups. In addition, the effects of the addition of soybean protein isolate (SPI) and montmorillonite (MMT) on the polymer electrolyte ion conductivity, lithium ion migration number, and electrode interface performance were investigated. After the test, it was found that the polymer electrolyte membrane with MMT and SPI had an ion conductivity of 2.56 × 10−4 S cm−1 at room temperature, an electrochemical stability window of 5.1 V, and a Li+ transfer number of 0.77. When assembling Li/LiTFSI-MMT-SPI-PVDF/Li batteries, the symmetric battery has a stable electrode interface because it can circulate stably for more than 100 h at a very small polarization voltage. Graphical Abstract

Recently, porous organic cages (POCs) have emerged as a novel porous material with many merits and are widely utilized in many application fields. In this work, for the first time, molecular dynamics simulations were performed to investigate the mechanism of lysozyme adsorption onto the CC3 crystal, a kind of widely studied POC material. The simulation results show that lysozyme adsorbs onto the surface of CC3 with "top end-on," "back-on," or "side-on" orientations. It is found that the van der Waals interaction is the primary contribution to the binding; the conformation of the lysozyme is well preserved during the adsorption process. This provides some evidence for its biocompatibility and feasibility in biorelated applications. Arginine plays an important role in mediating the adsorption through nonpolar aliphatic chains. More importantly, the distribution and structure of the water layer on the POC surface has a significant impact on adsorption. This study provides insights into the development of POC materials with defined morphologies for the adsorption of biomolecules and may help the rational design of biorelated systems.

Although metal-organic frameworks (MOFs) show numerous advantages over other crystalline materials, their industrial relevances have been impeded owing to their many drawbacks such as environmental impacts and economic costs of their synthesis. A green preparation pathway could greatly reduce the environmental costs, energy, and the need for toxic organic solvents, and consequently reduce the production cost. Thus, the most desirable synthesis route is the replacement of harsh organic solvents with aqueous solutions to abate environmental and economic impacts. This review summarizes recent research advancements of water-based routes for MOF synthesis and gives a brief outline of the most prominent examples. The challenges and prospects of the commercialization of promising MOFs in the future are also presented. This study aims to offer necessary information regarding the green, sustainable, and industrially acceptable fabrication of MOFs for their commercial applications in the future.

A novel fluorinated biphenyldicarboxylate ligand of 3,3',5,5'-tetrafluorobiphenyl-4,4'-dicarboxylic acid (H2-TFBPDC) and its terbium metal-organic framework, {[Tb2(TFBPDC)3(H2O)]·4.5DMF·0.5H2O}n (denoted as JXNU-6), were synthesized. JXNU-6 exhibits a three-dimensional (3D) framework built from one-dimensional (1D) terbium carboxylate helical chains bridged by TFBPDC2- linkers. The 3D framework of JXNU-6 features 1D fluorine-lined channels. The gas adsorption experiments show that the activated JXNU-6 (JXNU-6a) displays distinct adsorption behavior for propyne (C3H4) and propylene (C3H6) gases. The effective removal of a trace amount of C3H4 from C3H6 was achieved by JXNU-6a under ambient conditions, which is demonstrated by the column-breakthrough experiments. The modeling studies show that the preferential binding sites for C3H4 are the exposed F atoms on the pore surface in 1D channels. The strong C-H···F hydrogen bonds between C3H4 molecules and F atoms of TFBPDC2- ligands dominate the host-guest interactions, which mainly account for the excellent C3H4/C3H6 separation performance of JXNU-6a. This work provides a strategy for specific recognition toward C3H4 over C3H6 through the C-H···F hydrogen bond associated with the fluorinated organic ligand.

Lignin-based nanomaterials fabricated by solution self-assembly in organic-aqueous solvent mixtures are among the most attractive biomass-derived products. To accurately control the structure, size, and properties of lignin-based nanomaterials, it is important to achieve fundamental understanding of its dissolution and aggregation mechanisms. In this work, atomic force microscopy (AFM) and molecular dynamics (MD) simulations are employed to explore the dissolution and aggregation behavior of enzymatic hydrolysis lignin (EHL) in different organic-aqueous solvent mixtures at molecular scale. EHL was found to dissolve well in appropriate organic-aqueous solvent mixtures, such as acetone-water mixture with a volume ratio of 7:3, whereas it aggregated in pure water, ethanol, acetone, and tetrahydrofuran. The interactions between the EHL-coated AFM probe and the substrate were 1.21±0.18 and 0.75±0.35 mN m-1 in water and acetone, respectively. In comparison, the interaction decreased to 0.15±0.08 mN m-1 in acetone-water mixture (7:3 v/v). MD simulations further indicate that the hydrophobic skeleton and hydrophilic groups of lignin could be solvated by acetone and water molecules, respectively, which significantly promoted its dissolution. Conversely, only the hydrophobic skeleton or the hydrophilic groups were solvated in organic solvent or water, respectively, inducing serious aggregation of lignin.

The separation of ethane (C2H6) from ethylene (C2H4) is of prime importance in the production of polymer-grade C2H4 for industrial manufacturing. It is very challenging and still remains unexploited to fully realize efficient C2H6/C2H4 separation in the emerging hydrogen-bonded organic frameworks (HOFs) due to the weak nature of hydrogen bonds. We herein report the benchmark example of a novel ultrarobust HOF adsorbent (termed as HOF-76a) with a Brunauer-Emmett-Teller surface area exceeding 1100 m2 g-1, exhibiting the preferential binding of C2H6 over C2H4 and thus highly selective separation of C2H6/C2H4. Theoretical calculations indicate the key role of the nonpolar surface and the suitable triangular channel-like pores in HOF-76a to sterically "match" better with the nonplanar C2H6 molecule than the planar C2H4, thus affording overall stronger multipoint van der Waals interactions with C2H6. The exceptional separation performance of HOF-76a for C2H6/C2H4 separation was clearly demonstrated by gas adsorption isotherms, ideal adsorbed solution theory calculations, and simulated and experimental breakthrough curves. Breakthrough experiments on HOF-76a reveal that polymer-grade ethylene gas can be straightforwardly produced from 50/50 (v/v) C2H6/C2H4 mixtures during the first adsorption cycle with a high productivity of 7.2 L/kg at 298 K and 1.01 bar and 18.8 L/kg at 298 K and 5.0 bar, respectively.

In this work, an all-solid-state biomaterial electrolyte derived from phthaloyl starch and poly(vinylidene fluoride) (PVDF) was introduced. Phthaloyl starch (PS) was prepared with the starch and the phthalic anhydride via a chemical method. The introduction of C=O group through the starch esterification improved the migration of the lithium ions in the all-solid-state electrolyte membrane. The AC impedance test revealed that the addition of the phthaloyl starch promoted the conductivity of electrolytes, which can reach up to 2.04 × 10−4 S cm−1 at room temperature, and the electrochemical stability window (ESW) can achieve 4.20 V. Herein, the phthaloyl starch-PVDF–based electrolyte membrane possessed the lithium-ion transference number of 0.396. The half-cell Li/SPE/LiFePO4 had a better charge and discharge performance, that is, 93.9 mAh g−1 and 92.2 mAh g−1 after the 50th cycle at 0.5 C and at room temperature.

With a higher theoretical energy density relative to Li ion batteries (LIBs) and abundance of elemental sulfur, the lithium sulfur (L-S) batteries were regarded as the promising next-generation high energy density storage devices for the protable electronics and electric vehicles. However, there were some main challenges stemming from the polysulphide dissolution and the high flammability of the sulfur which limited the further application of the lithium sulfur Li–S batteries. Here, we reported a facile method to prepare the quasi solid-state Li–S batteries (LSBs) with sulfur nanoparticles electrode and PVDF-based solid polymer electrolyte (SPE), which had less flammability, electrochemical stability and ionic conductivity. The prepared PVDF-based solid polymer electrolyte possessed the conductivity ∼10−4 S cm−1 at 25 °C and the lithium ions transference number of 0.49. GITT demonstrated the Li+ transport diffusion mechanism in the active S@nano-TiO2 cathode of the quasi solid-state lithium–sulfur battery. It was important to get the smooth diffusion path for the lower resistance in the charging process. Because of the high content and the sulfur uniform distribution on the nanoscale titanium dioxide (TiO2), the S@nano-TiO2 cathode exhibited its performance. The first cycle discahrge specific capacity was 1160 mAh g−1 at 0.15C at room temperature.

Physical adsorption of gas molecules in micro porous materials is an exothermic process, with desorption entropy driving a decrease in uptake with temperature. Enhanced gas sorption with increasing temperature is rare in porous materials and is indicative of sorbate initiated structural change. Here, sorption of C2H6, C3H6, and C3H8 in a flexible microporous metal-organic framework (MOF) {Cu-(FPBDC)]•DMF}n (NKU-FlexMOF-1) (H2FPBDC = 5-(5-fluoropyridin-3-yl)-1,3-benzenedicarboxylic acid) that increases with rising temperature over a practically useful temperature and pressure range is reported along with other small molecule and hydrocarbon sorption isotherms. Single X-ray diffraction studies, temperature-dependent gas sorption isotherms, in situ and variable temperature powder X-ray diffraction experiments, and electronic structure calculations were performed to characterize the conformation-dependent sorption behavior in NKU-FlexMOF-1. In total, the data supports that the atypical sorption behavior is a result of loading-dependent structural changes in the flexible framework of NKU-FlexMOF-1 induced by sorbate-specific guest framework interactions. The sorbates cause subtle adaptations of the framework distinct to each sorbate providing an induced-fit separation mechanism to resolve chemically similar hydrocarbons through highly specific sorbate sorbent interactions. The relevant intermolecular contacts are shown to be predominantly repulsion and dispersion interactions. NKU-FlexMOF-1 is also found to be stable in aqueous solutions including toleration of pH changes. These experiments demonstrate the potential of this flexible microporous MOF for cost and energy efficient industrial hydrocarbon separation and purification processes. The efficacy for the separation of C3H6/C3H8 mixtures is explicitly demonstrated using NKU-FlexMOF-1a (i.e., activated NKU-FlexMOF-1) for a particular useful temperature range.'

Global environmental pollution issue has boosted the development of novel analytical techniques with high efficiency and accuracy for detection of hazardous contaminants. Strategies based on electrochemical, electrochemiluminescent, or photoelectrochemical analysis are among the promising detection approaches to provide rapid and sensitive analysis. Currently, combining ratiometric assay with such strategies can further promote their sensing reliability and reproducibility in complex conditions. This review highlights recent advances of ratiometric electrochemical, electrochemiluminescent, and photoelectrochemical sensors in the past 2 years. Their signal generation strategies and analysis applications, particularly for the environmental contaminant detection, are discussed in detail, and a future prospect in this area from us is also provided.

An electrochemiluminescence (ECL) aptasensor based on poly(ethylenimine) functionalized nitrogen-doped carbon nanodots (NCDs@PEI) composite as co-reactant, and Ru(bpy)32+ nanosheets (RuNSs) as luminophor was constructed for the specific analysis of bisphenol A (BPA). On account of the double improvement functions of NCDs and PEI on RuNSs, the as-developed aptasensor exhibited superior ECL properties. In order to further enhance the selectivity of the RuNSs-NCDs@PEI system for BPA detection, we innovatively introduced the BPA aptamer to construct a novel ECL aptasensor. Compared with that without aptamer and with random DNA, the constructed aptasensor performed higher specificity for BPA determination under the interference of structural analogues. The as-prepared ECL aptasensor exhibited a wide linear range of 1.0 × 10−10 - 1.0 × 10−4 mol L−1, and a relatively low detection limit of 3.3 × 10−11 mol L−1 for BPA detection with good stability and repeatability. Finally, when the ECL aptasensor made use of BPA analysis in water samples, the obtained results were confirmed by high performance liquid chromatography-ultraviolet spectrum (HPLC-UV) method, verifying its good accuracy. The novel aptasensor provided a new sensing platform for BPA in water samples.

A novel dual-modal fluorometric and colorimetric method was developed for glucose detection using MnO2 sheets and carbon quantum dots(CQDs). The glucose could be oxidized by glucose oxidase, in accompanied with the formation of H2O2 intermediate, which resulted in the decomposition of MnO2 sheets, as well as the MnO2 sheets(brown) changed to Mn2+ ions(colorless), which induced the absorption of MnO2 sheet decreased and the fluorescence of CQDs increased, consequently. The linear detection ranges of glucose are 5–1000 µmol/L by fluorescent method and 5–60 µmol/L by colorimetric method. The limits of detection of these two measurements are 2.11 and 2.18 µmol/L, respectively. This method is easy to conduct, has reasonable sensitive and selectivity, and could be applied for the glucose detection in real human serum.

peer-reviewed Simultaneous removal of trace amounts of propyne and propadiene from propylene is an important but challenging industrial process. We report herein a class of microporous metal–organic frameworks (NKMOF‐1‐M) with exceptional water stability and remarkably high uptakes for both propyne and propadiene at low pressures. NKMOF‐1‐M separated a ternary propyne/propadiene/propylene (0.5 : 0.5 : 99.0) mixture with the highest reported selectivity for the production of polymer‐grade propylene (99.996 %) at ambient temperature, as attributed to its strong binding affinity for propyne and propadiene over propylene. Moreover, we were able to visualize propyne and propadiene molecules in the single‐crystal structure of NKMOF‐1‐M through a convenient approach under ambient conditions, which helped to precisely understand the binding sites and affinity for propyne and propadiene. These results provide important guidance on using ultramicroporous MOFs as physisorbent materials.

Separating acetylene from light hydrocarbon mixtures like ethylene is a very important process for downstream industrial applications. Herein, we report a new MOF [CuL2(SiF6)] (UTSA-220, L = (1E,2E)-1,2-bis(pyridin-4-ylmethylene)hydrazine) with dual functionalities featuring optimal pore size with strong binding sites for acetylene. UTSA-220 exhibits apparently higher uptake capacity for C2H2 than those for other light hydrocarbons. The potential of this material for trace C2H2 removal from C2H4 has also been demonstrated by a dynamic breakthrough experiment performed with C2H2/C2H4 (1/99 v/v) under simulated industrial conditions. According to the dispersion-corrected density functional theory (DFT-D) simulation, SiF62– and azine moieties serve as preferential binding sites for C2H2, indicating the feasibility of the dual functionalities incorporated in UTSA-220 for adsorbent-based C2H2 separations.

In this work, we show that precise control of the pore size and functionality in an ultramicroporous metal–organic framework platform can finely tune the adsorption selectivity between acetylene and carbon dioxide at will.

Recently, MXenes, due to their abundant advantages, have been widely applied in energy storage, separation, catalysis, biosensing, et al. In this study, parallel tempering Monte Carlo and molecular dynamics methods were performed to investigate lysozyme adsorption on different functionalized Ti3C2Tx (-O, -OH, and -F). The simulation results show that lysozyme can adsorb effectively on Ti3C2Tx surfaces, and the order of interaction strength is Ti3C2O2 > Ti3C2F2 > Ti3C2(OH)2. Electrostatics together with van der Waals interactions control protein adsorption. The orientation distributions of lysozyme adsorbed on the Ti3C2O2 and Ti3C2F2 surfaces are more concentrated than that on the Ti3C2(OH)2 surface. During adsorption, the conformation of lysozyme remains stable, suggesting the good biocompatibility of Ti3C2Tx. Besides, the distribution of the interfacial water layer on the Ti3C2Tx surface has a certain impact on protein adsorption. This study provides theoretical insights for understanding the biocompatibility of 2D Ti3C2Tx materials and may help us evaluate the engineering of their surfaces for future biorelated applications.

Separation of C2H4 from C2H4/C2H2/C2H6 mixture with high working capacity is still a challenging task. Herein, we deliberately design a Th-metal-organic framework (MOF) for highly efficient separation of C2H4 from a binary C2H6/C2H4 and ternary C2H4/C2H2/C2H6 mixture. The synthesized MOF Azole-Th-1 shows a UiO-66-type structure with fcu topology built on a Th6 secondary building unit and a tetrazole-based linker. Such noticeable structure, is connected by a N,O-donor ligand with high chemical stability. At 100 kPa and 298 K Azole-Th-1 performs excellent separation of C2H4 (purity > 99.9%) from not only a binary C2H6/C2H4 (1:9, v/v) mixture but also a ternary mixture of C2H6/C2H2/C2H4 (9:1:90, v/v/v), and the corresponding working capacity can reach up to 1.13 and 1.34 mmol g−1, respectively. The separation mechanism, as unveiled by the density functional theory calculation, is due to a stronger van der Waals interaction between ethane and the MOF skeleton., Separation of ethylene from C2 ternary mixture with high working capacity is a challenging task. Here, the authors report a Th-azole framework (Azole-Th-1) for highly efficient purification of ethylene from C2H4/C2H6 and C2H4/C2H2/C2H6 mixtures, respectively.

Two-dimensional (2D) materials have been studied extensively as monolayers 1-5, vertical or lateral heterostructures 6-8. To achieve functionalization, monolayers are often patterned using soft lithography and selectively decorated with molecules 9,10. Here we demonstrate the growth of a family of 2D materials that are intrinsically patterned. We demonstrate that a monolayer of PtSe2 can be grown on a Pt substrate in the form of a triangular pattern of alternating 1T and 1H phases. Moreover, we show that, in a monolayer of CuSe grown on a Cu substrate, strain relaxation leads to periodic patterns of triangular nanopores with uniform size. Adsorption of different species at preferred pattern sites is also achieved, demonstrating that these materials can serve as templates for selective self-assembly of molecules or nanoclusters, as well as for the functionalization of the same substrate with two different species.

The liquid–liquid equilibrium (LLE) data for the three ternary systems, methyl butyl ketone (MBK) + o-, m-, p-cresol + water, were measured at 333.2 K and 353.2 K under 101 kPa in this work. Distribution coefficient and selectivity for cresols were calculated from the experimental tie-line data to evaluate the performance of MBK extracting cresols from the aqueous solution. The experimental tie-line data were correlated by the NRTL and UNIQUAC activity coefficient models, and both models showed good agreement with the experimental data. The COSMO-SAC model (conductor-like screening model for segment activity coefficient) was employed to predict LLE phase diagrams for the studied systems with root mean square deviations less than 3%.

Liquid–liquid equilibrium (LLE) data were measured for the ternary system of water + resorcinol + mesityl oxide under atmospheric pressure at temperatures of (298.2, 323.2, 333.2, 343.2 and 353.2) K. The reliability of the experimental data was verified by the Hand and Bachman equations. The distribution coefficient and selectivity were calculated from the experimental LLE data, which showed high efficiency of mesityl oxide extracting resorcinol from the aqueous solution. The NRTL and UNIQUAC models were employed to fit the measured experimental LLE data and yield corresponding binary interaction parameters.

There are great challenges in developing efficient adsorbents to replace the currently used and energy-intensive cryogenic distillation processes for olefin/paraffin separation, owing to the similar physical properties of the two molecules. Here we report an ultramicroporous metal–organic framework [Ca(C4O4)(H2O)], synthesized from calcium nitrate and squaric acid, that possesses rigid one-dimensional channels. These apertures are of a similar size to ethylene molecules, but owing to the size, shape and rigidity of the pores, act as molecular sieves to prevent the transport of ethane. The efficiency of this molecular sieve for the separation of ethylene/ethane mixtures is validated by breakthrough experiments with high ethylene productivity under ambient conditions. This material can be easily synthesized at the kilogram scale using an environmentally friendly method and is water-stable, which is important for potential industrial implementation. The strategy of using highly rigid metal–organic frameworks with well defined and rigid pores could also be extended to other porous materials for chemical separation processes.

Propylene (C 3 H 6 )/propane (C 3 H 8 ) separation is one of the most challenging as well as most energy-intensive separation processes in the petrochemical industry. Herein we report a microporous metal–organic framework ELM-12 with appropriate channels where efficient separation of C 3 H 6 over C 3 H 8 is achieved via the kinetic separation effect. Time-dependent kinetic adsorption, density-functional theory calculation and breakthrough experiments collaboratively demonstrate that the considerable diffusivity difference between C 3 H 6 and C 3 H 8 accounts for the excellent separation performance of ELM-12. The high kinetic C 3 H 6 /C 3 H 8 separation factor (204 at 298 K), large breakthrough time interval, and easy regeneration process of this MOF, make it a promising adsorbent for this important separation task. Furthermore, this material is highly stable under ambient condition and its production can be easily scaled up, rendering it quite favorable for practical industrial application.

Separation of propyne/propylene (C3H4/C3H6) is more difficult and challenging than that of acetylene/ethylene (C2H2/C2H4) because of their closer molecular sizes. A comprehensive screening of a series of metal–organic frameworks with broad types of structures, pore sizes, and functionalities was carried out. UTSA‐200 was identified as the best separating material for the removal of trace C3H4 from C3H4/C3H6 mixtures. Gas sorption isotherms reveal that UTSA‐200 exhibits by far the highest C3H4 adsorption capacity (95 cm3 cm−3 at 0.01 bar and 298 K) and record C3H4/C3H6 selectivity, which was mainly attributed to the suitable dynamic pore size to efficiently block the larger C3H6 molecule whilst the strong binding sites and pore flexibility capture smaller C3H4. This material thus provides record purification capacity for the removal of C3H4 from a 1:99 (or 0.1:99.9, v/v) C3H4/C3H6 mixture to produce 99.9999 % pure C3H6 with a productivity of 62.0 (or 142.8) mmol g−1.

A novel hairy-shaped Ni nanowire embedded nitrogen and sulfur dual-doped carbon nanofibers (Ni/N,S-CNFs) with superior electrocatalytic properties for urea oxidation reaction (UOR) was reported. The Ni/N,S-CNFs was prepared by electrospinning and carbonization process, using melamine-trithiocyanuric acid (MTCA) aggregates as both the N and S element sources. Noteworthy, MTCA also favored the formation of Ni nanowire via vapor liquid-solid mechanism, while Ni nanoparticles loaded CNFs (Ni/CNFs) was obtained without MTCA. For UOR tests, a high peak current intensity of 37.0 mA mg−1 was obtained on Ni/N,S-CNFs at 0.42 V (vs. SCE), 2-times higher of that on Ni/CNFs. Besides, the catalytic stability of Ni/N,S-CNFs was also improved. The enhanced catalytic properties of Ni/N,S-CNFs for UOR were ascribed to its unique Ni nanowires structure as well as the N, S dual-doping. Our work reveals that the property improvement of metal-based catalysts could be achieved by the heteroatom doping to fine the metal nanostructure.

Propene (C3H6)/propane (C3H8) separation is an important but challenging industrial task. Adsorptive separation using porous materials tends to be an energy- and cost-effective strategy. In this work, a flexible porous MOF named NJU-Bai8 is demonstrated to be a promising adsorbent for the effective separation of C3H6 and C3H8 in a wide temperature range from 298 to 348 K due to its flexible microporous structure, which provides unique guest responsive molecule accommodation. Adsorption isotherms, ideal adsorbed solution theory (IAST) prediction of separation ability, and transient breakthrough on both simulation and experiment were performed to evaluate its separation selectivity and cycling experiments were carried out to explore its structural stability. It was found that the C3H6/C3H8 uptake ratio and IAST selectivity of NJU-Bai8 is 43.2 and 4.6 at 298 K and 20 kPa, respectively. The breakthrough time interval for C3H6 and C3H8 is over 10 min for a C3H6/C3H8/He (20%/20%/60%) mixture under ambient conditions, and this separation ability can maintain more than 10 cycles. Detailed analysis reveals that a guest-dependent pressure induced gate-opening effect in the flexible framework of this MOF is indeed responsible for the observed unique selective adsorption and separation performances. This material also shows good regenerability, being favorable for possible industrial application.

A novel compound, [Ni(DCPTP)]n (termed Ni-DCPTP), based on the 4'-(3,5-dicarboxyphenyl)-2,2',6',2 `'-terpyridine (DCPTP2-) ligand was presented here. Ni-DCPTP has a three-dimensional structure with a the topology featuring one-dimensional (1D) helical channels. Ni-DCPTP shows an efficient removal of a trace amount of C2H2 from a C2H2/C2H4 (1/99) mixture with an excellent C2H4 productivity as demonstrated by both the transient breakthrough simulations and breakthrough experiments, generating the polymer-grade C2H4 gas (C2H2

This work presents a selective and reliable visible-light driven photoelectrochemical (PEC) chlopyrifos sensor using nitrogen functionalized graphene quantum dots/3D bismuth oxyiodine (NFGQDs/3DBiOI) hybrid hollow microspheres (HHMs) as a remarkable photoelectrode. In this protocol, a facile one-pot solvothermal reaction was used for the synthesis of the new NFGQDs/3DBiOI HHMs, which achieved significant enhancement (ca. 18-fold) photocurrent generation compared to pure BiOI microspheres by virtue of the band gap narrowing and the electron transfer acceleration of such HHMs. In addition, the introduction of chlorpyrifos pesticide enabled the formation of Bi-chlorpyrifos complex which resulted in quenching the charge transfer efficiency, thus leading to a decrease in photocurrent intensity and selective PEC recording of chlorpyrifos level. This novel PEC sensor exerted predominant performance for chlorpyrifos detection including wide linear range (0.1–50 ng mL−1), low detection limit (0.03 ng mL−1), satisfactory selectivity and also good feasibility in real water sample analysis. The strategy presented here implying that a three-dimensional hollow nanostructure would play a crucial role in developing multifarious novel detection methodologies in PEC sensing fields.

In the present work, a new electrochemical sensor using anodic stripping voltammetry from N-doped carbon quantum dots-graphene oxide hybrid (NCQDs-GO) for the simultaneous determination of cadmium ion (Cd 2+ ) and lead ion (Pb 2+ ) is developed. In the hybrid, both the NCQDs and GO have large electroactive surface areas and abundant oxygen-containing functional groups, which supply active sites for the efficient adsorption of heavy metal ions by electrostatic interaction to improve the sensor sensitivity. The NCQDs homogeneously distribute on the surface of GO and play an important role in re-oxidizing metals into ions for stripping analysis. Based on these excellent advantages, the electrochemical Cd 2+ and Pb 2+ sensor using a NCQDs-GO hybrid modified glassy carbon electrode (NCQDs-GO/GCE) exhibits superior analysis performance than those using just NCQDs on GCE (NCQDs/GCE) and just GO on GCE (GO/GCE), such as wide linear range (11.24–11241 μg/L for Cd 2+ and 20.72–10360 μg/L for Pb 2+ , respectively), low detection limit (7.45 μg/L for Cd 2+ and 1.17 μg/L for Pb 2+ , respectively), good reproducibility and selectivity. Moreover, satisfactory testing recoveries are obtained for the simultaneous detection of Cd 2+ and Pb 2+ in lake water and tap water, suggesting that NCQDs-GO hybrid is a promising material for the fabrication of electrochemical heavy metal ion sensor.

The development of a general method for the facile synthesis of hierarchical porous metal–organic frameworks (H-MOFs) with tunable porosities is important because of their widespread applications. Herein, through the ingenious use of different neutral organic amines as templates, we report the development of a green and versatile method to synthesize three H-MOFs (Cu-BTC, ZIF-8, and ZIF-90) with tunable morphologies and porosities. The selected neutral amine template molecules deprotonated organic ligands and facilitated the formation of H-MOFs while guiding the formation of meso- and macropores. These high quality as-synthesized H-MOFs possessed micro-, meso-, and macropore hierarchical structures and high thermal stability after the amine templates were removed by simple washing and drying. The as-prepared Cu-BTC H-MOFs exhibited more than 2 times higher activity than conventional microporous Cu-BTC in catalyzing Henry reaction. Our facile strategy establishes a green and general route to synthesize a large variety of H-MOFs for various applications, particularly when large molecules or biomolecules are involved.

Single-molecule protein sequencing is essential for a wide range of research and application fields, where the recently emerging 2D nanopores have open unprecedented possibilities. The protein translocating through a 2D nanopore plays vital roles in the nanopore-based analysis, where various detection or sequencing method could be employed. It is critically important to study the protein translocating through various 2D nanopores, which may help design efficient nanopore devices. However, few 2D materials other than graphene have been studied in this context yet. In this work, molecular dynamics (MD) simulations were employed to investigate the feasibility of single-molecule protein sequencing with a MoS2 nanopore. Both phenylalanine–glycine repeat peptides and a peptide with the sequence taken from the thioredoxin protein were studied in their extended unfolded state, which adsorbed onto the MoS2 membrane spontaneously. These peptides kept adsorbing onto MoS2 and permeated unidirectionally through the Mo...

Graphene-based materials might serve as an ideal platform for the regulation and promotion of metalloprotein electron transfer (ET); however, the underpinning mechanism at the molecular level has not yet been fully revealed. The orientation of cytochrome c (Cyt c) on surfaces is vital for ET. In this work, the orientation of Cyt c on graphene and graphene oxide (GO) surfaces, as well as the dominant driving forces, the conformational change and the ET pathways were investigated by molecular dynamics simulations. The results show that Cyt c is adsorbed onto the GO surface mainly through lysine residues; whereas hydrophobic interaction contributes to the Cyt c adsorption on graphene surface. There is no significant conformational change of Cyt c upon adsorption. The heme plane of Cyt c tends to be horizontally oriented and far away from the graphene surface, which is not conducive to ET. On the GO surface, the heme plane is slightly deviated from the normal direction to the surface and the axial ligand Met80 is much closer to the surface, which facilitates the ET. These findings shed some light on the ET mechanism of Cyt c on graphene-based materials and provide guidance for the development of bionic electronic devices.

Polyvinylidene fluoride (PVDF) was used as a membrane matrix, and then many groups of experiments with different additives were carried out to investigate the factor that affects conductivity of the solid polymer electrolyte (SPE). Impedance measurements were performed using an electrochemical work station. Data obtained through alternating current (AC) impedance measurements revealed that the conductivity of the blending membrane was improved. The presence of hydroxyl end-groups and some electron-donating groups in the additives was helpful for increasing the conductivity. In particular, when PVP and EDTA were added, the conductivity of the polymer electrolyte could achieve a value of 7.19 × 10−4 S cm−1 at 25 °C and a lithium ion transference number of 0.49. The electrochemical stability window was about 4.3 V (vs. Li+/Li).

Despite tremendous efforts, precise control in the synthesis of porous materials with ideal nanocages for desired gas separation applications still remains a challenge. Microporous metal–organic frameworks (MOFs) have provided rich chemistry to enable precise control and design of structures, pore cavities, and functionalities at the molecular level. Here, we propose and design a microporous MOF (termed as ZJUT-1, ZJUT = Zhejiang University of Technology) with a fine-tuned nanocage, exhibiting the desired size, shape, and functionalities that are suitable for trapping a single propyne (C3H4) molecule. Adsorption and computational studies indicate that such optimized nanocages can not only reduce the uptake of propylene (C3H6), but also strengthen the C3H4–host interactions through multiple hydrogen-bonding between SiF62−/–NH2 and C3H4 molecules. This material thus shows remarkably different C3H4 and C3H6 adsorption capacities, with the largest uptake ratio of 3.06 at 1 bar and 298 K, affording a very high selectivity (up to 70) for C3H4/C3H6 (1/99) separation. The actual breakthrough experiments demonstrate that ZJUT-1 can efficiently remove trace amounts of C3H4 from the important raw C3H4/C3H6 mixtures under ambient conditions with 0.19 mmol g−1 C3H4 uptake capacity to produce 99.9995% pure C3H6.

A novel metal–organic framework, ZJU-196, with extraordinary acid–base resistant stability has been successfully synthesized, exhibiting highly efficient separation of acetylene from C2H2/CO2 mixtures under ambient conditions.

We report a facile, green, and versatile synthetic route that exploits hydroxy double salt (HDS)–template synergy to achieve hierarchically structured metal–organic frameworks (H-MOFs) with high space–time yields (STYs). Hierarchically structured HKUST-1 and ZIF-8 were synthesized using the cooperative template strategy within 30 min (crystallization time). The resulting MOF products exhibited multimodal, hierarchically porous structures with meso-/macropores interconnected with micropores, as revealed by scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption isotherms, and pore size distributions. The porosities of the produced H-MOFs varied with the amount and type of template. The synergistic effect of the HDS and template on meso-/macropore generation was elucidated. The synergistic effect disclosed here dramatically extends the choice of templates for H-MOF synthesis at room temperature and pressure. Furthermore, the rapid synthetic method is readily scalable with an STY of up to 2366 kg m−3 d−1, a new record for the synthesis of hierarchically structured HKUST-1. The green, versatile, and sustainable method developed in this work provides a new direction for the rapid synthesis of various H-MOFs with tuneable porosities and high STYs for a wide range of applications.

Surface functionalization of nanoparticles (NPs) with stealth polymers (e.g., hydrophilic and zwitterionic polymers) has become a common strategy to resist nonspecific protein adsorption recently. Understanding the role of surface decoration on NP-biomembrane interactions is of great significance to promote the application of NPs in biomedical fields. Herein, using coarse-grained molecular dynamics (CGMD) simulations, we investigate the interactions between stealth polymer-coated gold nanoparticles (AuNPs) and lipid membranes. The results show that AuNPs grafted with zwitterionic polymers can more easily approach the membrane surface than those coated with hydrophilic poly(ethylene glycol) (PEG), which can be explained by the weak dipole-dipole interaction between them. For zwitterionic AuNPs which can undergo pH-dependent charge conversion, different interaction modes which depend on the polymer protonation degree are found. When the protonation degree is low, the particles just adsorb on the membrane surface; at moderate protonation degrees, the particles can directly translocate across the lipid membrane through a transient hydrophilic pore formed on the membrane surface; the particles are fully wrapped by the curved lipid membrane at high protonation degrees, which may lead to endocytosis. Finally, the effect of polymer chain length on the cellular uptake of zwitterionic polymer-coated AuNPs is considered. The results demonstrate that longer polymer chain length will block the translocation of AuNPs across the lipid membrane when the protonation degree is not high; however, it can improve the transmembrane efficiency of AuNPs at high protonation degrees. We expect that these findings are of immediate interest to the design and synthesis of pH-responsive nanomaterials based on zwitterionic polymers and can prompt their further applications in the field of biomedicine.

Herein, we firstly report a novel N-doped graphene quantum dots decorated N-doped carbon nanofibers (NGQDs@NCNFs) composite and its application to construct highly sensitive electrochemical sensor for nitrite determination. The NGQDs@NCNFs composite was prepared by combining electrospinning, carbonization and a facile route of one-step hydrothermal method. The as-prepared composite possessed free-standing film structure and high flexibility, which was favorable for electrode modification. NGQDs successfully grafted on the surface of NCNFs, thus avoiding the large aggregation and maintaining the large electroactive surface area of NGQDs. While the NCNFs acted as a novel support for NGQDs attachment and benefited fast electron transfer. The electrocatalytic performance of the NGQDs@NCNFs composite was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. It is revealed that the electrochemical nitrite sensor developed based on the novel NGQDs@NCNFs composite exhibited superior analysis performance to previously reported nitrite sensors, such as wide linear range (5–300 μM, R2 = 0.999; 400–3000 μM, R2 = 0.997), low detection limit (3 μM), excellent reproducibility and selectivity, and good testing recoveries for the detection of nitrite present in sausage, pickle, lake water and tap water. These results suggest that NGQDs@NCNFs composite could be a promising and convenient material for the fabrication of electrochemical sensors.

CuIn(Se x S1−x )2 thin film is prepared by the electrodeposition method for the absorption layer of the solar cell. The CuIn(Se x S1−x )2 films are characterized by cyclic voltammetry measurement for the reduction of copper, indium, selenium and sulfur in selenium and sulfur in aqueous solutions with sodium citrate and without sodium citrate. In the four cases, the defined reduction process for every single element is obtained and it is observed that sodium citrate changes the reduction potentials. A linear relationship between the current density of the reduction peak and (scan rate v)1/2 for copper and indium is achieved, indicating that the process is diffusion controlled. The diffusion coefficients of copper and indium ions are calculated. The diffusional coefficient D value of copper is higher than that of indium, and this is the reason why the deposition rate of copper is higher. When four elements are co-deposited in the aqueous solution with sodium citrate, the quaternary compound of CuIn(Se x S1−x )2 is deposited together with Cu3Se2 impure phases after annealing, as found by XRD spectra. Morphology is observed by SEM and AFM. The chemical state of the films components is analyzed by XPS. The UV-Visible spectrophotometer and electrochemistry workstation are employed to measure the photoelectric properties. The results show that the smooth, uniform and compact CuIn(Se x S1−x )2 film is a semiconductor with a band gap of 1.49 eV and a photovoltaic conversion efficiency of 0.45%.

The ionic liquid polymer electrolyte (IL-PE) membrane is prepared by ultraviolet (UV) cross-linking technology with polyurethane acrylate (PUA), methyl methacrylate (MMA), ionic liquid (Py13TFSI), lithium salt (LiTFSI), ethylene glycol dimethacrylate (EGDMA), and benzoyl peroxide (BPO). N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (Py13TFSI) ionic liquid is synthesized by mixing N-methyl-N-propyl pyrrolidinium bromide (Py13Br) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The addition of Py13TFSI to polymer electrolyte membranes leads to network structures by the chain cross-linking. The resultant electrolyte membranes display the room temperature ionic conductivity of 1.37 × 10−3 S cm−1 and the lithium ions transference number of 0.22. The electrochemical stability window of IL-PE is about 4.8 V (vs. Li+/Li), indicating sufficient electrochemical stability. The interfacial resistances between the IL-PE and the electrodes have the less change after 10 cycles than before 10 cycles. IL-PE has better compatibility with the LiFePO4 electrode and the Li electrode after 10 cycles. The first discharge performance of Li/IL-PE/LiFePO4 half-cell shows a capacity of 151.9 mAh g−1 and coulombic efficiency of 87.9%. The discharge capacity is 131.9 mAh g−1 with 95.5% coulombic efficiency after 80 cycles. Therefore, the battery using the IL-PE exhibits a good cycle and rate performance.

In this work, liquid-liquid equilibrium (LLE) data for the water + propionic acid or butyric acid + mesityl oxide ternary systems were measured at (298.2 and 323.2) K under atmospheric pressure. The reliability of the experimental tie-line data was verified by the Othmer-Tobias and Hand equations. The distribution coefficient and selectivity, calculated from the LLE data, showed high efficiency for mesityl oxide extracting propionic or butyric acid from the aqueous solution. A comprehensive comparison with various other extractants not only confirmed the high extraction efficiency of mesityl oxide, but also revealed some general guide lines for further screening extractants for carboxylic acids. The experimental data were successfully correlated by both UNIQUAC and NRTL models, yielding binary interaction parameters for relevant process simulations.

Liquid–liquid equilibrium (LLE) for the methyl tert-butyl ketone (MTBK) + o-, m-, and p-cresol + water ternary systems, at temperatures of (298.2, 313.2, and 323.2) K and 101 kPa, were determined in this work. High distribution coefficient and selectivity values were calculated from the LLE data, which indicated that MTBK extracted cresols from wastewater with high efficiency. MTBK also has good physical properties (e.g., low solubility in water, suitable boiling point). The experimental results were regressed and correlated by the NRTL and UNIQUAC activity coefficient models, which both predicted LLE data in close agreement with experiments with RMSD below 3.5%. The corresponding binary interaction parameters were also regressed by these two models, which would be useful for separation process designing or optimizing.

The removal of trace amounts of propyne from propylene is critical for the production of polymer-grade propylene. We herein report the first example of metal-organic frameworks of flexible-robust nature for the efficient separation of propyne/propylene mixtures. The strong binding affinity and suitable pore confinement for propyne account for its high uptake capacity and selectivity, as evidenced by neutron powder diffraction studies and density functional theory calculations. The purity of the obtained propylene is over 99.9998%, as demonstrated by experimental breakthrough curves for a 1/99 propyne/propylene mixture.