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The effect of storage conditions on the optimal MOF pore volume and methane working capacity has been analyzed, and the benchmark NPF-200 was discovered.

Globally, researchers have devoted consistent efforts to producing excellent coating properties since coating plays an essential role in enhancing electrochemical performance and surface quality. In this study, TiO2 nanoparticles in varying concentrations of 0.5, 1, 2, and 3 wt.% were added into the acrylic-epoxy polymeric matrix with 90:10 wt.% (90A:10E) ratio incorporated with 1 wt.% graphene, to fabricate graphene/TiO2 -based nanocomposite coating systems. Furthermore, the properties of the graphene/TiO2 composites were investigated by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), ultraviolet-visible (UV-Vis) spectroscopy, water contact angle (WCA) measurements, and cross-hatch test (CHT), respectively. Moreover, the field emission scanning electron microscope (FESEM) and the electrochemical impedance spectroscopy (EIS) tests were conducted to investigate the dispersibility and anticorrosion mechanism of the coatings. The EIS was observed by determining the breakpoint frequencies over a period of 90 days. The results revealed that the TiO2 nanoparticles were successfully decorated on the graphene surface by chemical bonds, which resulted in the graphene/TiO2 nanocomposite coatings exhibiting better dispersibility within the polymeric matrix. The WCA of the graphene/TiO2 coating increased along with the ratio of TiO2 to graphene, achieving the highest CA of 120.85° for 3 wt.% of TiO2. Excellent dispersion and uniform distribution of the TiO2 nanoparticles within the polymer matrix were shown up to 2 wt.% of TiO2 inclusion. Among the coating systems, throughout the immersion time, the graphene/TiO2 (1:1) coating system exhibited the best dispersibility and high impedance modulus values (Z0.01Hz), exceeding 1010 Ωcm2.

A new series of coumarin-yl-chalcone derivatives (3a-m) had been designed and synthesized through different reactions such as aromatic addition, cyclization and Claisen-Schmidt reactions in good yields (54-78%). 5-acetyl-4-(2-hydroxyphenyl) -6-methyl-3, 4-dihydropyrimidin-2(1H) -one (1) has been synthesized by multi-component one pot reaction of salicylaldehyde, methyl acetoacetate and urea, which was further reacted with malonic acid employing ZnCl2 catalyst to yield 5-acetyl-4-(4-hydroxy-2-oxo-2H-chromen-8-yl) -6-methyl-3, 4-dihydropyrimidin-2(1H) -one (2). The title compounds (3a-m) were synthesised by reacting 5-acetyl-4-(4-hydroxy-2-oxo-2H-chromen-8-yl) -6-methyl-3, 4-dihydropyrimidin-2(1H)-one (2) with different aromatic aldehydes in the presence of potassium hydroxide. In silico studies, a preliminary screening method for predicting the anti-cancer activity was performed for the synthesized compounds (3a-m) against Src, Alb tyrosine kinase and homology model protein (PDB ID: 4csv). The derivatives 3h and 3m showed moderate binding energies. The in vitro cytotoxic activity was evaluated for the compounds 3h and 3m by using human cancer cell-line morphology and MTT assay against three human cell-lines A549 (Lung), Jurkat (Leukemia) and MCF-7 (Breast). The results indicate that the derivatives 3h and 3m display significant anti-cancer activity, however it was found to be less cytotoxic when compared to the standard used i.e. Imatinib.

An efficient metal-free domino reaction leading to structural/electronically divergent 1,2-dihydropyridines from easily accessible propargyl vinyl anilines via N-phenyl 3-aza-Cope sigmatropic rearrangement is reported with good to excellent yields using 1,2-dichlorobenzene as solvent under thermal conditions. Spirocyclic substitution is also tolerated under the present optimized conditions.

Mesoporous α-iron oxide@graphitized-carbon nitride nanocomposites (α-Fe2O3@g-C3N4-NCs) were synthesized using urea-formaldehyde (UF) resins at 400 °C/2 h. The mesoporous nature of the prepared nanocomposites was observed from electron microscopy and surface area measurements. The electrochemical measurements show the bifunctional nature of mesoporous α-Fe2O3@g-C3N4-NCs in electrolysis of water for oxygen evolution and oxygen reduction reactions (OER/ORR) using 0.5 M KOH. Higher current density of mesoporous α-Fe2O3@g-C3N4-NCs reveals the enhanced electrochemical performance compared to pure Fe2O3 nanoparticles (NPs). The onset potential, over-potential and Tafel slopes of mesoporous α-Fe2O3@g-C3N4-NCs were found lower than that of pure α-Fe2O3-NPs. Rotating disc electrode experiments followed by the K-L equation were used to investigate 4e− redox system. Therefore, the mesoporous α-Fe2O3@g-C3N4-NCs bifunctional electro-catalysts can be considered as potential future low-cost alternatives for Pt/C catalysts, which are currently used in fuel cells.

A series of 3-aryl indazoles and 1-methyl-3-aryl indazole derivatives are prepared with exceptional yields by coupling with several arylboronic acids and methylation by two dissimilar approaches. The as-prepared indazole derivatives (3a-3j) and their N-methyl derivatives (5a-5j) are evaluated for in vitro anticancer activity against two cancer cell lines, HCT-116 and MDA-MB-231. The results reveal that the indazole derivatives tested display mild to moderate anticancer activities against the cell lines tested. We believe that slight structural modification of these active derivatives may yield better prospective anticancer drugs and demand further experimental investigations, especially in the area of anticancer research.

The hydrogen evolution reaction (HER) is important for the advancement of next-generation electrochemical energy devices. The search for an alternative inexpensive catalyst for energy conversion to replace expensive and rare noble metals is of high priority. There has been a significant push to investigate electrocatalysis of various layered materials for hydrogen evolution. However, the electrocatalytic activity of layered MAX phases remains largely unexplored. Herein, electrocatalytic activity studies of MAX (Ti2AlC, Ta2AlC, Ti2SnC, Ti3SiC2, V2AlC, Mo2TiAlC2, and Cr2AlC) phases are conducted. Material and electrochemical characterization are carried out to understand the morphology and catalytic activity, respectively. From Tafel slope analysis, it was found that proton adsorption is the rate-limiting step for all the MAX phases studied. Double transition-metal MAX carbides (Mo2TiAlC2) showed better catalytic activity for HER than single transition-metal MAX carbides.

A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C–N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/ nucleophilic substitution and a subsequent domino intra and intermolecular C–N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products. However, the simplicity, environmental acceptability, and cost effectiveness of copper makes this method more practical.

Copper nanoparticles were synthesized following their characterization by XRD, SEM-EDX and TEM techniques. These nanoparticles were used to remove new generation pollutant ketoprofen up to 89% at optimal conditions of 50 mg/L concentration, 50 min, 5.0 pH, 1.0 g/L dose and 25 °C. The adsorption followed the Langmuir, Temkin and Dubinin - Radushkevich models describing good adsorption of ketoprofen in water. The adsorption followed pseudo-first-order and liquid film diffusion mechanism. The adsorption was spontaneous and exothermic as proposed by the thermodynamics data. The supramolecular mechanism was purposed for the adsorption. Remarkably, the adsorption process was appropriate at low contact time. These properties of the adsorption made this development applicable to natural water resources, making the process economic and eco-friendly. So, this adsorption method may be used to remove ketoprofen in water easily at an inexpensive level.

3D-printing technology is widely accepted as a scalable and advanced manufacturing procedure for the fabrication of electrodes for electrochemical applications. 3D-printed carbon-based electrodes can be used for electrochemical analysis, replacing conventional carbon electrodes. However, a bare 3D-printed carbon electrode exhibits poor electrochemical performance. Herein, a post-treatment of 3D-printed electrodes was carried out using catalytically active materials to improve their electrochemical performance. We used a dip-coating technique which is a more universal, facile, and cost-effective approach compared with other conventionally used techniques such as atomic layer deposition or electrodeposition. The 3D-printed nanocarbon electrodes were dip-coated with MXene (Ti3C2Tx) and different transition metal dichalcogenides such as MoS2, MoSe2, WS2, and WSe2 to study their catalytic activity towards the hydrogen evolution reaction (HER). This study demonstrates a simple method of improving the catalytic surface properties of 3D-printed nanocarbon electrodes for energy conversion applications.

Hybrid materials based on metal-organic frameworks (MOFs) and nanoparticles (NPs) have gained considerable popularity in a variety of applications. Particularly, these types of materials have demonstrated excellent efficiency in heterogeneous catalysis due to the synergistic effect between the components. Herein, we report a simple, eco-friendly, photocatalytic method for the fabrication of Zr containing MOF-801 and a silver (Ag) NPs-based hybrid (Ag@MOF-801). In this method, the photocatalytic property of the central metal ion (Zr) of MOF was exploited to promote the formation and deposition of Ag NPs on the surface of the MOF-801 under the irradiation of visible light. The successful incorporation of Ag NPs was ascertained by powder X-ray diffraction (XRD) and UV-Vis analysis, while the morphology and surface area of the sample was determined by N2 adsorption–desorption and scanning electron microscopy (SEM), respectively. The resulting Ag@MOF-801 hybrid served as a highly efficient catalyst for the transesterification of used vegetable oil (UVO) for the production of biodiesel. The Ag@MOF-801 catalyst exhibited superior catalytic activity compared to its pristine MOF-801 counterpart due to the enhanced surface area of the material.

Mobile self-propelled micro/nanorobots are mobile binding surface that improved the sensitivity of many biosensing system by “on-the-fly” identification and isolation of different biotargets. Proteins are powerful tools to predict infectious disease progression such as COVID-19. The main methodology used to COVID-19 detection is based on ELISA test by antibodies detection assays targeting SARS-CoV-2 virus spike protein and nucleocapside protein that represent an indirect SARS-CoV-2 detection with low sentitivy and specificity. Moreover ELISA test are limited to used external shaker to obtain homogenously immobilization of antibodies and protein on sensing platform. Here, we present magnetic microrobots that collective self-assembly through immuno-sandwich assay and they can be used as mobile platform to detect on-the-fly SARS-CoV-2 virus particle by its spike protein. The collective self-assembly of magnetic microrobots through immuno-sandwich assay enhanced its analytical performance in terms of sensitivity decreasing the detection limit of SARS-CoV-2 virus by one order of magnitude with respect to the devices previously reported. This proof-of-concept of microrobotics offer new ways to the detection of viruses and proteins of medical interest in general., Graphical abstract Image, graphical abstract

The isoreticular principle has been applied to construct two copper metal-organic framework (MOF) analogues with different porosities for the adsorptive capture of CO2 from N2 and CH4 at 1 atm and 298 K. By using a 4-substituted isophthalate linker with a bulky nitro group, the microporous MOF [Cu(BDC-NO2)(DMF)] (UTSA-93 or CuBDC-NO2; H2BDC-NO2 = 4-nitroisophthalic acid and DMF = N,N'-dimethylformamide) has been synthesized with mot topology, showing a compact pore structure with a size of 6.0 × 7.0 A2 in contrast to that of 6.9 × 8.5 A2 in the prototypical MOF with a bromo group. The optimized pore structure allows the nitro-functionalized MOF to capture CO2 with a higher capacity of about 2.40 mmol g-1 under ambient conditions, in contrast to 1.08 mmol g-1 in the bromo-functionalized analogue. The adsorption selectivity of CuBDC-NO2-a for a CO2/N2 (15:85) mixture (28) under ambient conditions is also higher than that of the bromo-substituted prototype (25) and comparable with those of several MOF materials. Moreover, dynamic breakthrough experiments of the nitro-functionalized MOF have been performed to illustrate its separation potential toward a CO2/N2 mixture.

The decentralized fabrication of sensors using 3D-printing technology and low power requirements of electrochemical detection promise to revolutionize point-of-care sensing. One of the obstacles is that the 3D-printed devices are often not catalytic to the target analytes. Here, we develop a non-enzymatic printed nanocarbon electrode sensor to detect sugars (glucose and sucrose) via copper and nickel electroplating over a 3D-printed conducting electrode. The morphological and spectroscopic characterizations of copper-plated and nickel-plated 3D-printed carbon electrodes were performed. Scanning electron micrographs show the formation of metal nanoparticles over the surface of a 3D-printed nanocarbon electrode. X-ray photoelectron spectroscopy reveals the composition and chemical states of the metal coating. Electrochemical characterization via cyclic voltammetry and chronoamperometry was carried out, and glucose and sucrose sensing were performed. This method of on-demand decentralized sensor fabrication and modifications should find broad applications.

Additive manufacturing, also termed 3D printing, enables economical, dynamic and rapid fabrication of customisable three-dimensional (3D) devices catering for specialised functions. Herein, we report the fabrication of 3D-printed graphene electrodes by fused deposition modelling (FDM), which were then used for the electrochemical detection of the mycotoxin zearalenone (ZEA). Chemical and electrochemical pre-treatment procedures were applied to remove the inert polylactic acid external layer from the graphene electrodes, exposing and activating the inner graphene surface. These procedures enhanced the sensitivity of the electrodes towards electrochemical detection of ZEA. The activated 3D-printed graphene electrodes displayed a good linear response (r = 0.995) over a wide concentration range (10 to 300 µM). This proof-of-concept application opens up a wide range of possibilities for the fabrication of 3D-printed electrochemical devices for use in food analysis and food safety.

A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C&ndash, N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C&ndash, N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.

Advancement of technology for the sustainable production of biodiesel is of significant importance in fighting against rising fuel costs due to the fast depletion of fossil fuels. In this regard, the application of highly efficient MOFs (metal–organic frameworks)-based materials as acidic, basic, or supported heterogeneous catalysts plays a crucial role in enhancing the efficiency of biodiesel production processes. In this report, we demonstrate the synthesis and catalytic application of Zr-fumarate-MOF (also known as MOF-801) as a heterogeneous catalyst for the transesterification reaction of used vegetable oil (UVO) for the production of biodiesel. The formation of MOF-801 and its structural stability is confirmed by a variety of characterization techniques including XRD, SEM, EDX, FT-IR, BET, and TGA analyses. The results revealed the formations of highly crystalline, cubic MOF-801 possessing thermal stability below 500 °C. The MOF-801 catalyst demonstrated moderate catalytic activity during transesterification of UVO (~60%) at 50 wt.% of methanol: oil, 10 wt.% catalyst loading, 180 °C reaction temperature, and 8 h of reaction time. Furthermore, the catalyst has exhibited adequate reusability with a slight reduction in the reaction yield of up to ~10% after three cycles.

Solvothermal reaction of 3-aminoisonicotinic acid (Haina) and Cu(NO 3 ) 2 ·2.5H 2 O gave a novel two-dimensional (2D) microporous metal–organic framework, [Cu(aina) 2 (DMF)]·DMF ( 1 , DMF = N,N-dimethylformamide). Single-crystal X-ray crystallographic study of compound 1 revealed that Cu(II) ions are linked by aina − ligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity (void = 46.5%) with one-dimensional (1D) open channels (4.7 A × 4.8 A) functionalized by amino groups. Gas sorption measurements of 1 revealed selective carbon dioxide (CO 2 ) and acetylene (C 2 H 2 ) adsorption over methane (CH 4 ) and nitrogen (N 2 ) at ambient temperature.

Mesoporous α-iron oxide@graphitized-carbon nitride nanocomposites (α-Fe2O3@g-C3N4-NCs) were synthesized using urea-formaldehyde (UF) resins at 400 °C/2 h. The mesoporous nature of the prepared nanocomposites was observed from electron microscopy and surface area measurements. The electrochemical measurements show the bifunctional nature of mesoporous α-Fe2O3@g-C3N4-NCs in electrolysis of water for oxygen evolution and oxygen reduction reactions (OER/ORR) using 0.5 M KOH. Higher current density of mesoporous α-Fe2O3@g-C3N4-NCs reveals the enhanced electrochemical performance compared to pure Fe2O3 nanoparticles (NPs). The onset potential, over-potential and Tafel slopes of mesoporous α-Fe2O3@g-C3N4-NCs were found lower than that of pure α-Fe2O3-NPs. Rotating disc electrode experiments followed by the K-L equation were used to investigate 4e− redox system. Therefore, the mesoporous α-Fe2O3@g-C3N4-NCs bifunctional electro-catalysts can be considered as potential future low-cost alternatives for Pt/C catalysts, which are currently used in fuel cells.

3D printing is a manufacturing technique used to prototype devices with customized shapes composed of different materials, including carbon composites. Toxic phenolic compounds are a major environmental hazard. Herein, we demonstrate the use of carbon-based 3D-printed electrodes for the detection of chlorophenols and nitrophenols. The influence of pH on the voltammetric response was studied, and an alkaline pH was identified as the best environment for the detection of substituted phenols. Simultaneous detection of phenolic compounds was performed using differential pulse voltammetry. This approach appears promising for the fabrication of electrochemical sensors.

A twofold interpenetrated metal-organic framework, PMOF-3, composed of four kinds of polyhedra exhibits the highest selectivity of 157 for C2 H2 /CH4 separation at 296 K and 1 atm owing to the synergistic effect of the open metal sites, C≡C triple bonds, and microporous structure.

A new threefold interpenetrated pillared-layer microporous metal-organic framework, [Zn2 (cca)2 (4-bpdb)]n ⋅(DMF)2n (UTSA-85) (H2 cca=4-carboxycinnamic acid, 4-bpdb=1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, and DMF=N,N-dimethylformamide), has been designed and generated by the solvothermal reaction of mixed ligands (H2 cca and 4-bpdb) and Zn(NO3 )2 ⋅6 H2 O. Single-crystal XRD analysis disclosed that discrete paddle-wheel Zn2 (COO)4 clusters as secondary building units linked the cca ligands to give two-dimensional layers, which were further pillared by 4-bpdb ligands to form a threefold interpenetrated pillared-layer structure. The desolvated framework, UTSA-85 a, was revealed to exhibit permanent porosity with a BET surface area of 558 m2 g-1 and a high selectivity of 64 for C2 H2 /CH4 separation at 296 K owing to the microporous (≈5.0 A) structure and functional azine groups that decorated the pore channels.

Catalytic light-powered microrobots have become a major focus in the current autonomous self-propelled micromotors research. The attractiveness of such machines stems from the fact that these motors are liquid “fuel-free”, with their motion modulated by irradiation. It is assumed that as catalytic micro/nanoparticles, they can function eternally. We show here that Pt/TiO2 photo powered micromachines undergo corrosion and that they lose catalytic activity several days after deployment.

CoxOy&ndash, manganese carbonate (X%)(CoxOy&ndash, MnCO3 catalysts (X = 1&ndash, 7)) were synthesized via a straightforward co-precipitation strategy followed by calcination at 300 &deg, C. Upon calcination at 500 &deg, C, these were transformed to CoxOy&ndash, dimanganese trioxide i.e., (X%)CoxOy&ndash, Mn2O3. A relative catalytic evaluation was conducted to compare the catalytic efficiency of the two prepared catalysts for aerial oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using O2 molecule as a clean oxidant without utilizing any additives or alkalis. Amongst the different percentages of doping with CoxOy (0&ndash, 7% wt./wt.) on MnCO3 support, the (1%)CoxOy&ndash, MnCO3 catalyst exhibited the highest catalytic activity. The influence of catalyst loading, calcination temperature, reaction time, and temperature and catalyst dosage was thoroughly assessed to find the optimum conditions of oxidation of benzyl alcohol (BzOH) for getting the highest catalytic efficiency. The (1%)CoxOy&ndash, MnCO3 catalyst which calcined at 300 &deg, C displayed the best effectiveness and possessed the largest specific surface area i.e., 108.4 m2/g, which suggested that the calcination process and specific surface area play a vital role in this transformation. A 100% conversion of BzOH along with BzH selectivity &gt, 99% was achieved after just 20 min. Notably, the attained specific activity was found to be considerably larger than the previously-reported cobalt-containing catalysts for this transformation. The scope of this oxidation reaction was expanded to various alcohols containing aromatic, aliphatic, allylic, and heterocyclic alcohols without any further oxidation i.e., carboxylic acid formation. The scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and Brunauer&ndash, Emmett&ndash, Teller (BET) specific surface area analytical techniques were used to characterize the prepared catalysts. The obtained catalyst could be easily regenerated and reused for six consecutive runs without substantial decline in its efficiency.

A series of 3-aryl indazoles and 1-methyl-3-aryl indazole derivatives are prepared with exceptional yields by coupling with several arylboronic acids and methylation by two dissimilar approaches. The as-prepared indazole derivatives (3a-3j) and their N-methyl derivatives (5a-5j) are evaluated for in vitro anticancer activity against two cancer cell lines, HCT-116 and MDA-MB-231. The results reveal that the indazole derivatives tested display mild to moderate anticancer activities against the cell lines tested.

A hydrogen-bonded organic framework (HOF), HOF-7, based on a zinc porphyrin-based building block (ZnTDPP) with diaminotriazine moieties has been successfully constructed and structurally characterized (ZnTDPP = 5,10,15,20-tetrakis(4-(2,4-diaminotriazinyl)phenyl)porphyrinato zinc). Single-crystal X-ray diffraction analysis reveals that HOF-7 is built by the 2D layered subunits connected by the intermolecular hydrogen-bonding and π–π interaction, exhibiting two kinds of micropores with sizes of 3.2 × 4.7 A2 and 4.2 × 6.7 A2, respectively. This HOF exhibits permanent porosities as demonstrated in the CO2 sorption and selective adsorption of CO2 over N2.

Two Praseodymium-organic frameworks, [Pr2(NDC)2(NO3)2(DMA)4] (1) and [Pr3(NDC)4.5(DMF)3(H2O)] (2) (H2NDC = 2,6-naphthalenedicarboxylic acid; DMA = N,N-dimethylacetamide; DMF = N,N-dimethylformamide) have been synthesized and structurally characterized. The discrete Pr2(COO)4 cluster and 1D [Pr(COO)3]n rod act as the secondary building units in MOF 1 and MOF 2, respectively, leading to their different structures of 2D sheet and 3D rod-packing. Their permanent porosities have been also established.

Three solvent dependent structures of 2,6-diaminopurine in N,N′-dimethylforamide (DAP-1-DMF), water (DAP-2-H2O), and methoxybenzene (DAP-3-CH3OC6H5) have been structurally characterized. They exhibit different structures because of the different involvement of solvent molecules in the hydrogen bonded frameworks. The DAP molecules tend to be self-assembled with other DAP molecules through hydrogen bonding interactions. DAP has very similar hydrogen bonding interaction patterns to the established DAT group (2,4-diaminotriazinyl), underlying the potential of this new unit for the construction of porous hydrogen bonded organic frameworks.

A twofold interpenetrated metal-organic framework, PMOF-3, composed of four kinds of polyhedra exhibits the highest selectivity of 157 for C

A new threefold interpenetrated pillared-layer microporous metal-organic framework, [Zn