Search

Tailor-made unsaturated coordination of metal ions or organic linkers in zeolitic imidazole frameworks (ZIFs) has great potential in tuning the ZIFs’ properties and reactivity for their applications. Taking advantage of the solid-state thermal (SST) method as a facile and eco-friendly synthesis method, the rational coordination of metal ions with imidazole ligands in ZIF-67 through the SST method is investigated. The rational precursor ratio (metal-to-ligand source) under the solvent-free SST method emerges as a perfect strategy to tune the coordinately unsaturated sites within the ZIF-67 frameworks. Different analysis techniques, computational methods (DFT), and catalytic model reactions examine unsaturated coordination in ZIF-67 materials (defect structures). The unsaturated coordination provides unique characteristic properties on materials with excellent catalytic performance. However, the higher reactive properties are negotiated with weaker structural stability on materials. In addition, the post-SST approach is applied to enable rational coordination and modify the pristine ZIF-67 materials. The post-SST method rearranges and modifies coordination in the framework of materials. These findings are crucial to understanding the role of the uncoordinated degree to balance with structural stability based on ZIF-67, which is critical for effective heterogeneous catalysts.

Metal(ii)-carboxylate frameworks are an important class of MOF materials finding applications in gas storage, separation, sensing, catalysis, etc.Recently, their design, synthesis and characterization have been established at a very fast pace. Here two novel MOFs based on 5,5′-(([1,1′-biphenyl]-4,4′-dicarbonyl)bis(azanediyl))diisophthalic acid (H4L, an amide containing ligand) and transition metals (copper and zinc) are reported. Several characterization tools e.g., FT-IR, XRD, SEM, TGA, and XPS are used to characterize these MOFs. Single-crystal X-ray diffraction and Hirshfeld surface analyses are used to characterize the 3D structural framework. The void and cavity analysis revealed the strength of the crystal packing. Both MOFs followed multistage thermogravimetric disintegration profiles. The solvent molecules escaped around 200 °C and the structural changes due to decompositions in the frameworks continued till 500 °C. The morphological analysis for Zn-MOF and Cu-MOF showed uniform wedge-shaped rectangular blocks and spherical balls with dimensions around 100 and 50 μm, respectively. The amide functionalized Zn(ii)-carboxylate framework exhibited high catalytic activity (85–>99%) towards the solvent-free cycloaddition of CO2to different epoxides e.g., epichlorohydrin, propylene oxide, allyl glycidyl ether and glycidyl isopropyl ether with 100% selectivity under ambient conditions (i.e., 1 bar at 40 °C for 24 h) at very low catalyst loading. By adjusting the reaction conditions (T, P, and co-catalyst), the catalytic conversion reached 100% within only 2 hours. The results showed Zn-MOF as a superior and efficient catalyst compared to other reported MOFs. Additionally, the catalyst can be easily recovered and regenerated for repeated use without performance loss.

Acoustic-activated polarization at two-dimensional (2D) domains provide supplementary mechanisms for adjustment of empty and occupied orbitals at material heterointerfaces, activating a wide range of physicochemical applications. The piezoelectric nanodomains grown at 2D liquid-metal heterointerfaces represent a new class of polarization-dependent hybrid nanostructures with a highly challenging fabrication process. Here, the controlled growth of selenium-rich piezoelectric nanodomains on the nonpolar 2D surface of liquid Ga-based nanoparticles (NPs) enabled highly efficient and sustainable CO2conversion. The Ga-based NPs were engulfed in carbon nanotube (CNT) frameworks. The initial hindrance effects of CNT frameworks suppressed the undesirable Ga-Se amalgamation to guarantee the suitable functions of piezocatalyst. Simultaneously, the CNT-Se mesoporous network enhances the transport and interaction of ionic species at heterointerfaces, providing unique selectivity features for CO2conversion. Driven by acoustic energy, the multiple contributions of Ga-Se polarized heterointerfaces facilitated the piezoelectric switching and therefore increased the CO2conversion efficiency to the value of 95.8%. The inherent compositional and functional tunability of the Ga-Se nanojunction reveal superior control over the catalyst heterointerfaces and thereby show promising potential for nanoscale applications.

• Mixing sucrose and zinc nitrate hexahydrate can be used as a solvent-free synthesis procedure. • This method can produce zinc oxide nanoparticles (ZnO NPs) embedded in carbon foam. • The interface of ZnO NPs and porous carbon produces abundant interfacial polarization. • Its unique porous structure facilitates the generation of strong conduction losses and greatly enhances absorption. • The optimal synthesized ZnO/C-2 carbon material demonstrates the strongest absorption of –41.7 dB and covers almost the entire Ku band. Exploring a simple, rapid, solvent-free synthetic method for mass production of cheap, broadband microwave absorbers remains the main challenge. Here, a mild solvent-free procedure is reported to synthesize zinc oxide nanoparticles (ZnO NPs) embedded in porous carbon derived from mixing sucrose and zinc nitrate hexahydrate. The characteristic morphology and the ZnO NPs distribution in these composites were tuned using the different raw materials proportions. The mesoporous structure of porous carbon benefits the compositional advantages between carbon foam and ZnO NPs. The optimal synthesized ZnO/C-2 carbon material demonstrates the strongest absorption of –41.7 dB with a frequency of 14.5 GHz at a thin thickness of 2 mm, and its widest effective absorption is close to 6 GHz (12.2–17.8 GHz). This work produces a feasible route for the sensible design of other effective microwave absorbers for large-scale production. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) heterostructures of transition metal oxides (TMOs) are promising candidates for high-performance electrochemical supercapacitors (ESCs). Herein, sub-10 nm 2D SnO2-ZnO heterostructures were constructed on Au-modified SiO2/Si wafers by an atomic layer deposition (ALD) technique for ESC application. The cyclic voltammetry (CV) study revealed the pseudocapacitive-type Faradaic redox reactions of the 2D SnO2-ZnO heterostructure electrode with good reversibility. The electrode exhibited high energy storage capability with a high specific capacitance (Cs) of 538.90 F g–1at a scan rate and current density of 10 mV s–1and 8.0 A g–1, respectively. The corresponding energy density and the power density were 14.80 Wh kg–1and 2512.35 W kg–1, respectively, at 8.0 A g–1. The high energy storage capacity of the heterostructure electrode can be ascribed to the combination of improved infiltration and intercalation/deintercalation of electrolyte ions induced by the nanoscale thickness and enhanced redox activity of the heterostructure. Furthermore, the 2D electrode displayed excellent electrochemical robustness with a capacitance retention of 96.3% after 5000 charge/discharge cycles.

A facile method was developed from solid precursors to obtain zinc anchored in a nitrogen-doped carbon matrix (Zn-NCx) via the solid–solid thermal (SST) route. The applied method, to synthesize Zn-NCx, was completed under single-step and solvent-free conditions. Regarding the synthesis mechanism, the zeolitic-imidazole framework (ZIF-8) was first fabricated from solid mixed precursors at a low temperature of the SST process. In a continuous mode, the fabricated ZIF-8 was sacrificed at a high temperature of the SST process to obtain Zn-NCx. Detailed characterization was performed to investigate the solid–solid transformation of precursors during the SST route. This characterization confirmed that Zn-NCxconsists of zinc anchored in the nitrogen-doped carbon matrix. Also, due to the high porosity and N-functionalization, Zn-NCxexhibited excellent adsorption properties for CO2and was helpful in CO2/CH4separation. Furthermore, the chemical properties in hierarchical porous Zn-NCxwere demonstrated to act as a catalyst for CO2fixation. Interestingly, since the current method (SST) is solvent-free, this is a promising environmental route. The procedure has the potential for upscaling, revealing vast prospect for applications based on these carbon materials.

The dehydrogenation of primary alcohols to carboxylic acids is a crucial process in chemical industries such as fibers and plastics. Carboxylic acids, the resulting products, are not only important chemical raw materials but also fundamental pharmaceutical intermediates. Zn-based catalysts have gained attention as a promising option for this transformation owing to their economic cost and abundant reserves. However, stability issues, including structure collapse and morphological changes, have plagued the reported Zn-based catalysts during this transformation. In response to these challenges, this study focused on the design and development of Zn-based catalysts via controlled incorporation of Zn into nitrogen-doped porous carbon to modulate the numbers of defects and Lewis acid-base site pairs. Through extensive screening of various parameters, the best-performing catalyst, namely Zn@NC-800, exhibited high activity and remarkable stability, surpassing all the reported Zn-based catalysts. Moreover, this catalyst demonstrated great recyclability since it could maintain approximately 90 % yields after 9 cycles. Notably, the product formation rate of this catalyst could reach 3833 μmol·gcat.−1·h−1, exceeding that of most reported non-noble metal heterogeneous catalysts. Consequently, this study offers a promising approach for efficiently and stably catalyzing alcohol dehydrogenation reactions using non-noble metals.

•Nickel and Zinc azolium, bipyridine-based MOFs were synthesized and applied in the adsorption of anionic dyes.•Introduction of azolium moieties creates charges in the two MOFs.•The charged environment in the MOFs results in excellent anionic dye adsorption.•The carbene site of the azolium linker could be metallated with Pd.•The Pd-metallated MOFs are efficient catalysts for cross coupling reactions.

Graphic Abstract:

[Display omitted] • An inexpensive and facile approach to synthesize a bimetallic electrocatalyst. • Carbon foam physically mixed with ZIF-67 generates Co-Zn-CNTs after pyrolysis. • The Co-Zn-CNTs demonstrate remarkable catalytic activity towards OER and HER. • Co 3 ZnC species contribute to the excellent performance of the electrocatalyst. • Co 3 ZnC species are associated with enhanced durability. An efficient and facile approach to synthesize a bi-functional electrocatalyst via combining carbon foam with cobalt-centered zeolitic imidazolate framework (ZIF-67) is reported. The carbon foam was synthesized via dehydration of sugar utilizing zinc nitrate, forming Co 3 ZnC in the carbon matrix. To obtain Co hybridized and Co particles covered with carbon nanotubes embedded in a carbon matrix (Co-Zn-CNTs), physical mixing of both defines the critical point after pyrolysis. Higher content of N-related species and transition metal species in polyvalent states and well-grown multi-wall carbon nanotubes for charge transfer are achieved after the pyrolysis process. The obtained Co-Zn-CNTs catalyst was employed as cathode and anode for overall water splitting (HER and OER) and showed excellent performances. This development offers a low-cost and straightforward strategy to synthesize catalyst material for large-scale fuel cells and water splitting technologies. This development affords a precise method for effectively improving the electrocatalyst performance derived from the ZIF-67 precursor. [ABSTRACT FROM AUTHOR]

Graphical abstract:

Herein, a metal-free and solvent-free protocol was developed for the C–N coupling of heteroaryl halides and amines, which afforded numerous heteroaryl amines or their hydrochlorides without any external base. Further investigations elucidated that the basicity of amines and specific interactions derived from the X-ray crystallography analysis of 3j′·HClplayed pivotal roles in the reactions. Moreover, this protocol was scalable to gram scales and applicable to drug molecules, which demonstrated its practical value for further applications.

A facile and eco-friendly in situ thermal (IST) method was developed to synthesize zeolitic imidazole frameworks based on a 2-methylimidazole (2-MIM) linker (ZIF-67, ZIF-8, and Zn/Co-ZIF). A single-step and a short processing time with the lowest precursor ratio (M/L) and solvent-free provided an advantage of the IST method over the reported traditional synthesis procedures. A variety of synthesis parameters, including temperature, time, precursor, and gas atmosphere, were optimized to obtain excellent crystalline and porosity properties. In the following, different characterization techniques were comprehensively applied to verify the properties of the synthesized materials. Moreover, the beneficial chemical and physical properties of the synthesized material exhibited potential application for adsorption and catalysis. Overall, the IST method approach is a novel ZIF synthesis procedure generating high porous crystalline ZIFs. The IST is a green strategy avoiding solvent, activation, or post-treatment to remove unreacted residual, side-product, and guest molecules from the product. Additionally, the single-step IST process showed scalability for large-scale material synthesis.

To investigate the feasibility and effectiveness of applying in situ chemical oxidation (ISCO) on the remediation of sulfolane-contaminated groundwater, batch and pilot-scale studies were conducted in this study. The kinetics of sulfolane oxidation by Fenton and Fenton-like processes and optimal operational conditions were evaluated. The major control factors in the ISCO study included H2O2concentrations, ratio of H2O2to ferrous iron (mol/mol), molar ratios of oxidant to sulfolane, and catalyst effect. Results show that the Fenton reaction could obtain a complete sulfolane oxidation with the following operational conditions: 3% of H2O2, molar ratio of H2O2to ferrous iron = 1:0.5, and initial sulfolane concentration = 72 mg/L. The calculated pseudo-first-order decay rate constants (k′) were 1.32 × 10–1and 6.69 × 10–2min–1for sulfolane degradation under Fenton and Fenton-like oxidation reaction processes with 3% of H2O2concentration, respectively. However, the sequential Fenton-like operational pattern could be an alternate option to obtain a complete sulfolane removal efficiency. Results from the soil oxidant demand test show that approximately 25%–35% of supplied H2O2(3%) was consumed by soil organic matter, and thus, higher oxidant concentration would be required for field application. Sulfolane oxidation would result in sulfuric acid production, which caused the decrease in solution pH, and this would be beneficial to Fenton reaction. A sulfolane-contaminated groundwater site was selected for the pilot-scale study and Fenton oxidation process was applied for sulfolane degradation. Approximately, 600 L of H2O2solution (5%) [molar ratio of [H2O2]:[Fe2+] = 1:0.5] was injected into the injection well (IW) to oxidize sulfolane in situ. Up to 97% and 88% of sulfolane could be removed (initial sulfolane concentration = 68 mg/L) in the IW and a downgradient monitor well (located 5 m downgradient of the IW). Results from the batch and pilot-scale studies demonstrate that the Fenton reaction could be an applicable remedial option to oxidize sulfolane and cleanup sulfolane-contaminated groundwater.

Integrated energy systems (IES) have attracted increasing attention in recent years. Zn–air battery powered water splitting devices require the development of highly active and durable trifunctional electrocatalysts for the oxygen evolution, oxygen reduction, and hydrogen evolution reactions (OER/ORR/HER). However, engineering rational nano-scaled designs and achieving the required synergy are major challenges due to the lack/weak control of synthesis processes. Herein, ZIF-67 regular polyhedra were fabricated for the first time to incorporate single ZnO nanorods. Thereafter, pyrolysis sacrificed the nanorods and stimulated intriguing modifications on the ZnONR@ZIF-67-derived CoOx@N, O-doped hierarchical carbon (CoOx@NOC), not only from the outside-in, but also from the inside out. Consequently, an outstanding enhancement in OER/ORR/HER trifunctional activity was achieved. The CoOx@NOC based Zn–air battery showed a small initial charge–discharge voltage gap of 92 mV at 10 mA cm−2and a high specific capacity and maximum power density of 757.39 mA h gZn−1and 141.65 mW cm−2, respectively. A CoOx@NOC-based all-solid-state Zn–air battery (SS ZAB) was fabricated, which showed a high open circuit potential of 1.49 V. Two SS ZABs in series drove an overall water splitting system, which showed an intriguingly low potential of 1.51 V at 10 mA cm−2, surpassing most reported electrocatalysts. Thus, the excellent performance of CoOx@NOC implies its great potential to compete with noble metal electrocatalysts.

Mixed-matrix membranes (MMMs) with an ideal polymer–filler interface and high gas separation performance are very challenging to fabricate because of incompatibility between the fillers and the polymer matrix. This work provides a simple technique to prepare a series of cross-linked MMMs (xMMM@n) by covalently attaching UiO-66-NB metal–organic frameworks (MOFs) within the PEG/PPG–PDMS copolymer matrix via ring-opening metathesis polymerization and in situ membrane casting. The norbornene-modified MOF (UiO-66-NB) is successfully copolymerized and dispersed homogeneously into a PEG/PPG–PDMS matrix because of very fast polymer formation and strong covalent interaction between MOFs and the rubbery polymer. A significant improvement in gas permeability is achieved in membranes up to a 5 wt % MOF loading compared to the pristine polymer membrane without affecting selectivity. The CO2/N2separation performance of xMMM@1, xMMM@3, and xMMM@5 with 1, 3, and 5 wt % MOF loading, respectively, surpassed Robeson’s 2008 upper bound. In addition, the best performing membrane, xMMM@3 (PCO2= 585 Barrer and CO2/N2∼53), approaches the 2019 upper bound, indicating that the cross-linked MMMs (xMMM@n) are very promising for CO2separation from flue gas. The experimental results of our study were evaluated and are supported by theoretical data obtained using the Maxwell model for MMMs. Moreover, the developed MMMs, xMMM@ns, displayed outstanding antiplasticization performance at pressures of up to 25 atm and very stable antiaging performance for up to 11 months with good temperature switching behaviors.

Although research in renewables is growing at a tremendous rate, the world will still be greatly dependent on fossil fuels for at least the first half of this century. In the quest for more efficient and clean fuels, oil refining companies have turned their attention to processes such as reforming and alkylation technologies; in the latter process, isobutane is reacted with butenes and/or propylenes to produce, among others, branched isooctane, which is the main high-octane component of the gasoline pool. The main benefit of this process is the possibility to produce sulfur-free high-octane fuels, so important economic and environmental advantages are foreseen if investments in this area are realized. This Review analyzes and discusses the most recent progress on catalyst technologies, starting from the traditional sulfuric acid process and proceeding to newly emerging catalyst technologies such as solid acid and ionic liquid-based catalysts. We start with basic mechanistic analyses and conclude this Review with the new non-liquid acid-based commercial and emerging technologies for isobutane alkylation. Emphasis is given to the structure–activity relationships and the advantages and disadvantages present in every discussed catalyst material.

This study presents the influence of molecular interaction and molecular ordering on the physicochemical properties and the excess values of the binary mixtures containing several alkanediols and a symmetric cyclic ketone (cyclopentanone) at 298.15 K and 101.3 kPa. Thus, experimental values of the permittivity, density, and refractive index were determined for the alkanediol–cyclopentanone systems over the entire range of mole fraction. A series of straight-chain primary alkanediols, each having two primary hydroxyl groups, were 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentandiol. Meanwhile, the other alkanediols (1,2-propanediol and 1,3-butanediol) possesses both primary and secondary hydroxyl groups. The measured data were coherently analyzed by the conventional methods, leading to different excess values. The calculated excess quantities indicate the existence of hydrogen-bonding network in the studied systems. The excess values of relative permittivity, molar volume, and Kirkwood correlation factors were found to be negative for all of the binary mixtures, suggesting the formation of multimer structures, the reduction of the effective dipole moments, and the opposite alignment of dipoles in the mixtures. In order to support the experimental data, theoretical calculations were performed using density functional theory (DFT). The optimization of the structures were performed by the B3LYP/6-311G (d,p) DFT level.

Although some ligand transformations involved in metal complexes have been reported during water oxidation (WO) ((photo)chemical/electrochemical), such as ligand decomposition, partial oxidation, or complete dissociation, ligand photodissociation has not been reported yet. Here, we report the first example of ligand photodissociation in [Ru([9]-aneN3)(bpy)(DMSO)]2+, 1(bpy is 2,2′-bipyridine), under the frequently used conditions for screening water oxidation catalysts, and its relation to the catalyst activity. We demonstrate that the observed photodissociation in complex 1boosts its catalytic performance towards electrochemical WO and enables surface generation of electrochemically active species. Conversely, the absence of such a phenomenon in [Ru([9]-aneN3)(pic)(DMSO)]+, 2(pic is 2-picolinate), resulted in an unreactive catalyst towards WO. DFT calculations could explain the observed difference between complexes 1and 2aqueous solutions towards ligand partial-dissociation when exposed to light based on the activation barrier between triplet metal-to-ligand charge transfer (3MLCT) and dissociative metal-centered (3MC) excited states as well as the stability of the 3MC state. Whereas the 3MLCT–3MC transition for complex 2requires higher activation energy than that for complex 1, the resulting 3MC state is less stable than its 3MLCT state. Calculations involving the ligand exchange process reveal that a water molecule can replace one of the pyridine rings with a considerably lower activation barrier in the triplet state as compared to the singlet state.

A novel series of 2-(3-methyl-1,6-diphenyl-1H-pyrazolo[3,4-b]pyridin-4-yl)-5-aryl-1,3,4-oxadiazoles (4a–4h) has been synthesized from corresponding hydrazones (3a–3h) and evaluated their antiplatelet aggregation effect induced by arachidonic acid and collagen. Spectral data and elemental evaluation were used to confirm the structure of the compounds while molecular docking against cyclooxygenase 1 and 2 (COX1 & COX2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential. All synthesized compound exhibited more than 50% platelet aggregation inhibition against both arachidonic acid and collagen. Antiplatelet activities results showed that 4b and 4f compounds have highest % inhibition against arachidonic acid. High Egap and ionization potential values showed that the compound 4d, 4e and 4f were supposed to be more active and good electron donor while 4b, 4c, 4d, 4e, 4g and 4h might be more active due to more electrophilic sites. Interaction with more than one residues in the binding pocket of COX-1 in comparison with aspirin and ligand efficacy (LE) consequences showed that compounds have excellent action potential for COX-1. Computational evaluations are in good agreement with antiplatelet activities of the compounds. All compounds might be promising antiplatelet agents especially 4b, 4f and helpful in the synthesis of new drugs for the treatment of cardiovascular diseases (CVDs).

The reaction of carbon dioxide transformation is tremendously interesting in research societies from the viewpoint of carbon resource and also to resolve the environmental problem of carbon dioxide emission. Carbon dioxide (CO2) is a suitable C1 feedstock which can be converted into a number of valuable fine chemicals. The utilization of CO2not only helps to reduce the carbon emission but should also lead to economic benefits, if CO2is converted into chemicals for which there are significant demands or have a high added value. The reaction of CO2with methanol is one of the pathways to directly synthesize dimethyl carbonate. However, the catalyst is a key factor in the reaction development. Herein, in this review, the focus is made on materials for the catalyzed reaction for the direct synthesis of dimethyl carbonate (DMC) from CO2and methanol. The developed catalysts (homogeneous and heterogeneous catalysts) used so far are discussed, together with the respective operating conditions to obtain the optimum catalyst performance. Interesting ideas to allow the direct synthesis of carbonate products from CO2with methanol using developed novel catalysts with high performance and efficiency for the economy are offered in this review.

Developing a stable, cost-effective, and high-performance electrocatalyst is fundamental for practical alkaline electrolyzer applications; however, it remains a significant issue for researchers. Herein, we reported the fabrication of a heterostructure (CoSe2–CoP/CC) electrode material to work as an efficient electrocatalyst with a remarkable HER activity for alkaline Hydrogen Evolution Reaction (HER). Experimental results along with DFT calculations reveal that the transfer of an electron between CoSe2and CoP contributes towards enhanced H2O adsorption as well as dissociation with more optimized energies and a promoted Haddiffusion, resulting in an outstanding catalytic performance of HER showing relatively small overpotential value of 51 mV and 37 mV in alkaline (1.0 M KOH), and acidic (0.5 M H2SO4) electrolytes respectively to drive 10 mA/cm2of the current density.

Electrochromic devices, serving as smart glasses, have not yet been intelligent enough to regulate lighting conditions independent of external photosensing devices. On the other hand, their bulky sandwich structures have been suffering setbacks utilized for reflective displays in an effort to compete with mature emissive displays. The key to resolve both problems lies in incorporating the photosensing function into electrochromic devices while simplifying their configuration via replacing ionic electrolytes. However, so far it has not yet been achieved because of the essential operating difference between the optoelectronic devices and the ionic devices. Herein, a concept of a smarter and thinner device: “electrochromic photodetector” is proposed to solve such problems. It is all-solid-state and electrolyte-free and operates with a simple thin metal–semiconductor–metal structure via an electrolytic mechanism. As a proof of concept, a configuration of the electrochromic photodetector is presented in this work based on a tungsten trioxide (WO3) thin film deposited on Au electrodes via facile, low-cost solution processes. The electrochromic photodetector switches between its photosensing and electrochromic functions via voltage modulation within 5 V, which is the result of the semiconductor–metal transition. The transition mechanism is further analyzed to be the voltage-triggered reversible oxygen/water vapor adsorption/intercalation from ambient air.

A record-high HCHO capture capacity, reaching 49 mg g−1, is achieved in about ten minutes, on defective NH2-UiO-66(Zr) nano-octahedra. The adjacent bifunctional base/acid catalytic centers significantly facilitate the efficient HCHO adsorption and regenerative transformation of the adsorbed HCHO into less toxic formic acid and methanol.

Water-soluble homogeneous nickel catalysts have been rarely investigated for catalytic water oxidation as compared to their heterogeneous counterparts. Herein, we report homogenous electrochemical water oxidation by a nickel(ii) complex, ([NiL](PF6)2(L = bis(2-pyridyl-methylimidazolylidene)methane), based on a macrocyclic N-heterocyclic carbene/pyridine hybrid ligand under neutral and alkaline conditions. The catalyst displayed the stable catalytic current of 0.65 mA cm−2at the overpotential of 0.80 V (∼0.55 V at GCE for CV) with a ∼93% Faradaic efficiency at pH 9.0 for oxygen evolution in long-term bulk electrolysis. The CV, UV-vis, ESI-MS, SEM, and EDX results demonstrated that the catalyst was impressively stable even after long-term controlled potential electrolysis (CPE) (11 h) and homogeneous in nature. The synthesis of this catalyst is straightforward, and its complex is air and moisture stable. To the best of our knowledge, this is the first study on the investigation of a Ni–NHC complex for water oxidation under aqueous conditions (acetate/phosphate). According to the literature, the role of the phosphate ion in homogenous nickel-catalysed water oxidation was found to vary from catalyst poisoning to activation. Interestingly, the catalytic activity of our catalyst in phosphate buffer was significantly higher than that with acetate ions at the same pH value; this might indicate the key role of phosphate ions as proton acceptors, which boosted the catalyst activity viaenhanced PCET during catalysis.

Cesium salts (Cs2CO3, CsCl, and CsNO3) were used for the coupling of CO2and epoxides. These salts are highly active catalysts for the formation of cyclic carbonates from epoxides and CO2at ambient pressure (1 bar). The reaction proceeds with high conversions up to 100% and turnover numbers (TONs) up to 97 × 103.

A series of N-(4-aryloxyphenyl)phthalimides were synthesized and identified as new inhibitors of the cytochrome bc1complex. Furthermore, results obtained from computational simulations indicated that 3e′should bind to the Qosite of the bc1complex.

[Display omitted]

Densities and dynamic viscosities for organic binary mixtures of cyclohexane with toluene, o-xylene, and mesitylene were measured at T= (303.15 to 323.15) K and atmospheric pressure. The measurements were carried out over the entire range of composition using a bicapillary pycnometer and an A-type Ostwald viscometer. The excess molar volumes, thermal expansivities, and excess thermal expansivities were calculated from the experimental density data, while the viscosity deviations were obtained from the dynamic viscosity data. The excess results were correlated with the fourth-order Redlich–Kister-type polynomial equation. The excess properties of binary liquids were analyzed in terms of intermolecular interactions.

Electrically responsive plasmonic devices, which benefit from the privilege of surface plasmon excited hot carries, have supported fascinating applications in the visible-light-assisted technologies. The properties of plasmonic devices can be tuned by controlling charge transfer. It can be attained by intentional architecturing of the metal–semiconductor (MS) interfaces. In this study, the wafer-scaled fabrication of two-dimensional (2D) TiO2semiconductors on the granular Au metal substrate is achieved using the atomic layer deposition (ALD) technique. The ALD-developed 2D MS heterojunctions exhibited substantial enhancement of the photoresponsivity and demonstrated the improvement of response time for 2D Au–TiO2-based plasmonic devices under visible light illumination. To circumvent the undesired dark current in the plasmonic devices, a 2D WO3nanofilm (∼0.7 nm) was employed as the intermediate layer on the MS interface to develop the metal–insulator–semiconductor (MIS) 2D heterostructure. As a result, 13.4% improvement of the external quantum efficiency was obtained for fabricated 2D Au–WO3–TiO2heterojunctions. The impedancometry measurements confirmed the modulation of charge transfer at the 2D MS interface using MIS architectonics. Broadband photoresponsivity from the UV to the visible light region was observed for Au–TiO2and Au–WO3–TiO2heterostructures, whereas near-infrared responsivity was not observed. Consequently, considering the versatile nature of the ALD technique, this approach can facilitate the architecturing and design of novel 2D MS and MIS heterojunctions for efficient plasmonic devices.

A new heterogeneous NHC catalyst (Ag-NHC-MOF) was synthesized by the post-synthetic modification of an azolium-containing metal–organic framework. The structure of the catalyst was well defined and fully characterized using various techniques such as PXRD, FE-SEM, HR-TEM, XPS, FT-IR, TGA, BET, 1H-NMR, 13C-NMR, EDS, and ICP. The catalyst showed an excellent activity towards the A3-coupling reaction with a broad substrate scope. The A3-coupling reaction was performed under ambient conditions and full conversion was reached within just 1 hour for the model reaction. The heterogeneous silver NHC MOF (Ag-NHC-MOF) catalyst can be recycled and reused at least four times without a significant loss of activity. In comparison with previously reported heterogeneous catalysts applied for the A3-coupling reaction, the Ag-NHC-MOF demonstrates a superior performance for the A3-coupling reaction.