To obtain highly efficient supercapacitors with extraordinary capacitance, energy density, and cycle life, the design and development of new electrode materials having numerous active sites on the ...surface are essential. Not only the kind of material but also the surface morphology and microporous structure of the electrode plays an important role in the electrochemical performance of the supercapacitor. In the present work, a bimetallic Co/Mn-metal–organic framework (MOF) has been prepared using a simple hydrothermal method for supercapacitor application. This bimetallic MOF mainly produces a synergistic effect by connecting two kinds of metal ions through an organic ligand. The resulting bimetallic Co/Mn MOF electrode shows a high specific capacitance of 1176.59 F g−1 (2.76 F cm−2) at a current density of 3 mA cm−2 and excellent cycling stability over 5000 cycles. The constructed Co/Mn MOF//AC hybrid supercapacitor exhibits a specific energy of 57.2 Wh kg−1 at a specific power of 2000 W kg−1 and excellent capacity retention of 93.51% over 5000 cycles. These outstanding results are compared with those of similar devices in the literature, thus revealing that our approach is a desirable direction for future research on high-performance energy storage devices as well as hybrid supercapacitors.
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The adsorptive removal of tetracycline (TC) was studied with three types of zirconium-based metal–organic frameworks (Zr-MOFs), UiO-66, NU-1000 and MOF-525. The adsorption kinetics ...best fitted with the pseudo-second-order kinetic model and the adsorption equilibrium was rapidly reached within 40 min on UiO-66 and NU-1000, and 120 min on MOF-525. The adsorption isotherms best fitted with Sips model, and the maximum Sips adsorption capacities of TC on UiO-66, NU-1000 and MOF-525 were 145 mg·g−1, 356 mg·g−1 and 807 mg·g−1 respectively, which were much higher than common adsorbents. The X-ray photoelectron spectra measurements and the influence of pH suggested that the π-π interaction played a crucial role during the adsorption. Pore characteristics and topology of MOFs showed great effect on adsorption performance. The cages whose size match well with TC helped MOF-525 to get highest adsorption amount per surface area among MOFs we studied. The proper topology of NU-1000 contributed to its high adsorption rate. River water was also used to confirm the excellent adsorptive performance of these three Zr-MOFs in practical application. These results might aid us to comprehend the adsorption of TC on Zr-MOFs and expand the application of Zr-MOFs in water treatment for removal of emerging contaminants.
A novel dual functional composite (MOFL-TpBD) was prepared through solvothermal methods, with excellent Pb2+ ions separation and stable 2,4,6-Trinitrophenol (TNP) fluorescence detection performance. ...MOFL-TpBD was characterized by FTIR, XRD, XPS, SEM and TGA et al. The prepared material was used to extract Pb2+ ions, with an adsorption capacity of 21.74 mg g−1 calculated by Langmuir isotherm model. The limit of detection was 0.32 μg L−1, along with a linear range from 0.7 to 12 μg L−1 and a precision of 5.4% (1 μg L−1, n = 9), respectively, where MOFL-TpBD was adopted as adsorbent for Pb2+ ions preconcentration. The practical samples and reference water sample were measured by the provided method, with the satisfactory recoveries (91–110%) and reliable analytical results. MOFL-TpBD was capable of fluorescent sensing of TNP, with a linear range from 0.01 to 1 mM and a limit of detection of 3.52 μM, respectively, and a precision of 3.29% was obtained (0.2 mM, n = 11). Meanwhile, the recoveries ranged from 91% to 108% in analysis of TNP for the practical samples. The designed material provided a potential candidate material for the detection of heavy metal ions and explosives in environmental water samples.
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•A novel dual functional composite (MOFL-TpBD) was prepared through solvothermal methods.•The composite showed excellent lead ions separation and 2,4,6-trinitrophenol detection performance.•The analysis of trace lead and 2,4,6-trinitrophenol in environmental water samples was accomplished.
Quantification of how different environmental cues affect protein allocation can provide important insights for understanding cell physiology. While absolute quantification of proteins can be ...obtained by resource-intensive mass-spectrometry-based technologies, prediction of protein abundances offers another way to obtain insights into protein allocation. Here we present CAMEL, a framework that couples constraint-based modelling with machine learning to predict protein abundance for any environmental condition. This is achieved by building machine learning models that leverage static features, derived from protein sequences, and condition-dependent features predicted from protein-constrained metabolic models. Our findings demonstrate that CAMEL results in excellent prediction of protein allocation in E. coli (average Pearson correlation of at least 0.9), and moderate performance in S. cerevisiae (average Pearson correlation of at least 0.5). Therefore, CAMEL outperformed contending approaches without using molecular read-outs from unseen conditions and provides a valuable tool for using protein allocation in biotechnological applications.
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•The CoP-NC@NFP electrocatalyst is well prepared and characterized.•CoP-NC@NFP exhibited excellent electrochemical activity as well as good stability in overall water ...splitting.•CoP-NC@NFP have retained their structural property after stability.•CoP-NC@NFP offers excellent performance and good stability (over 200 h) in zinc-air battery.
Highly active, long-lasting, and low-cost nanostructured catalysts with efficient oxygen evolution and oxygen reduction reactions (OER and ORR) are critical for achieving high-performance zinc-air batteries. Herein, we developed CoP-nitrogen-doped carbon@NiFeP nanoflakes (CoP-NC@NFP), derived from MOF enriched with multiple active sites, for multifunctional water splitting and zinc-air battery applications. The experimental results revealed that the multiple active catalytic sites of CoP-NC@NFP were responsible for the excellent charge-transfer kinetics and electrocatalytic performance with respect to water splitting. This performance is comparable to that of precious metal catalysts in alkaline electrolytes (OER: overpotential of 270 mV; HER: overpotential of 162 mV; ORR: Tafel slope of 46 mV dec−1; overall water splitting device: cell voltage of 1.57 V at 10 mA cm−2) with excellent electrochemical durability. Additionally, the structural stability of the OER and the HER durability of the CoP-NC@NFP electrocatalyst were confirmed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) studies. Most impressively, zinc-air batteries (ZABs) assembled with CoP-NC@NFP as the air–cathode exhibit exceptionally high power density of 93 mW cm−2 and prolonged operational stability over 200 h compared with a ZAB equipped with a benchmark air–cathode. The outcome of this study opens a practical possibility for the preparation of efficient multifunctional catalysts free of noble metals for clean energy production and storage.
We have quantified inputs and fate of nutrients in European fresh and marine waters from 1990 to 2018. We have used the conceptual model GREEN to assess the impact of efforts on curbing nutrient ...pollution in European regions. In the first two decades, i.e. in the 1990s and through the start of the new millennium, nutrient inputs to waters decreased significantly. Nutrient pollution in freshwaters and to the sea largely reduced in all regions, although at different pace. However, around 2008–2010 trends in nutrient inputs changed, marking an increase in the last decade, particularly from agricultural diffuse sources. In some regions, current nutrient inputs to waters are close to those estimated at the beginning of the 1990s. At the end of the study period, nutrient concentrations in freshwaters remain above thresholds congruent with good ecological status of water bodies in most downstream reaches. European policies tackling point sources are close to reach their maximum impact. In the face of this approaching ceiling, sustainable nutrient management on agricultural land becomes pivotal for effective nutrient control in river basins. The regional approach highlighted differences across Europe that may provide tailored opportunities to plan effective strategies for achieving environmental targets.
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•Nitrogen and phosphorus loads in European regions are assessed for 1990–2018.•In that period phosphorus loads to sea reduced by 22 % and nitrogen loads by 6 %.•Nutrients still exceed good ecological status thresholds in most freshwaters.•2008–2010 marked a breakpoint for the increase of nutrient inputs from agriculture.
•Zn-MOF@GO nanohybrid was prepared via the ultrasound-assisted method.•Coating Zn-MOF@GO nanohybrid with CS produced CS/Zn-MOF@GO hybrid microspheres.•The CS/Zn-MOF@GO microspheres have been ...introduced as anticancer drug carriers.•5-Fu loaded CS/Zn-MOF@GO displayed the pH-sensitive drug release pattern.•Outcomes certified that CS/Zn-MOF@GO is an efficient anticancer drug carrier.
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In the current work, we investigated and compared the capability of the monodispersed chitosan (CS) microspheres, CS coated zinc-based metal-organic framework (CS/Zn-MOF) microspheres, and CS coated the hybrid of Zn-MOF with graphene oxide (CS/Zn-MOF@GO) microspheres as an anticancer drug carrier. The prepared samples were characterized through the common characterization techniques. The morphologies, sizes, and drug loading efficiency of the prepared compounds respectively were well-characterized, obtained, and compared with each other. The scanning electron microscopy (SEM) analysis displayed the particle size of the prepared microspheres in the range of 20–40 µm. The highest amount of 5-fluorouracil (5-Fu) loading was found for the ternary hybrid of CS/Zn-MOF@GO microspheres; ~45%. The 5-Fu loaded CS microspheres (5-Fu@CS/Zn-MOF@GO microspheres) with rough surfaces exhibited a pH-sensitive and sustained release pattern for loaded 5-Fu. So, the cumulative drug release amount at pH 5.0 was relatively two times greater than pH 7.4. Eventually, CS/Zn-MOF@GO microspheres exhibited acceptable enzymatic biodegradability and also good biocompatibility toward MDA-MB 231 cells line as an epithelial, human breast cancer cell. 41.2% cell viability after 48 treatment with 5-Fu@CS/Zn-MOF@GO microspheres confirmed the capability of 5-Fu loaded CS/Zn-MOF@GO microspheres in the tumor cell treatment. Based on the founded interesting results the CS/Zn-MOF@GO ternary hybrid microspheres could be proposed as a promising and hopeful candidate to applied in the localized anticancer delivery.
A graphene aerogel-zirconium-metal organic framework (GA-Zr-MOF) was synthesized and used as a membrane in a solid-phase extraction device to remove hydroquinone after immobilization of laccase. The ...adsorption rate of laccase onto this membrane reached 73.8 mg g
−1
, and it was mainly attributed to the adsorption effect of Zr-MOF. The membrane exhibited a satisfactory efficiency in removing hydroquinone (79%), which resulted from the combined effect of GA adsorption and catalysis by laccase. After five removal cycles, the removal rate remained at approximately 70%. The GA-Zr-MOF with immobilized laccase exhibited good operability and efficiency in the removal of hydroquinone.
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•Materials with abnormal physical or chemical properties are numerous among metal-organic frameworks and framework materials.•Unusual responses to stimulation range from ...counter-intuitive to thermodynamically forbidden.•Stimuli-responsive MOFs share large similarities with metamaterials.•These meta-MOFs have properties that go beyond the boundaries of common crystalline materials.
As the number of framework materials known and characterized in the literature grows, it becomes apparent that they can carry properties rarely encountered in more conventional, dense inorganic materials. Among these materials with unusual physical or chemical properties are the ubiquitous metal-organic frameworks, covalent organic frameworks, dense coordination polymers, and molecular frameworks. Many can respond to stimulation by displaying structural responses and changes in properties that range from counter-intuitive to thermodynamically forbidden. In that, they share large similarities with metamaterials, which are engineered to generate properties not found in “normal” materials. We review here the surprising behavior of these meta-MOFs and other framework materials that display properties “beyond” (μετά) the boundaries of common crystalline materials.
The separation of acetylene (C2H2) from carbon dioxide (CO2) is a very important but challenging task due to their similar molecular dimensions and physical properties. In terms of porous adsorbents ...for this separation, the CO2‐selective porous materials are superior to the C2H2‐selective ones because of the cost‐ and energy‐efficiency but have been rarely achieved. Herein we report our unexpected discovery of the first hydrogen bonded organic framework (HOF) constructed from a simple organic linker 2,4,6‐tri(1H‐pyrazol‐4‐yl)pyridine (PYTPZ) (termed as HOF‐FJU‐88) as the highly CO2‐selective porous material. HOF‐FJU‐88 is a two‐dimensional HOFs with a pore pocket of about 7.6 Å. The activated HOF‐FJU‐88 takes up a high amount of CO2 (59.6 cm3 g−1) at ambient conditions with the record IAST selectivity of 1894. Its high performance for the CO2/C2H2 separation has been further confirmed through breakthrough experiments, in situ diffuse reflectance infrared spectroscopy and molecular simulations.
The novel two‐dimensional ultramicroporous hydrogen‐bonded organic framework (HOF), denoted as HOF‐FJU‐88, is synthesized utilizing the organic linker 2,4,6‐tri(1H‐pyrazol‐4‐yl)pyridine. Once activated, HOF‐FJU‐88 demonstrates a notable selectivity for CO2 over C2H2 with an IAST selectivity index of 1894.
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