Synthesis Route Research Articles

Stretch-Induced Spin-Cast Membranes Based on Semi-Crystalline Polymers for Efficient Microfiltration.

Microfiltration membranes derived from semi-crystalline polymers face various challenges when synthesized through the extrusion-casting technique, including the use of large quantities of polymer, long casting times, and the generation of substantial waste. This study focuses on synthesizing these membranes using spin-casting, followed by stretch-induced pore formation. Recycled high-density polyethylene (HDPE) and virgin polyethylene powder, combined with a calcium carbonate filler, were used as the source materials for the membranes. The influence of the polymer-filler ratio with and without stretching on the morphology, tensile strength, and water flow rate was investigated. Optimal conditions were determined, emphasizing a balance between pore structure and mechanical integrity. The permeable membrane exhibited a water flow rate of 19 mL/min, a tensile strength of 32 MPa, and a water contact angle of 126°. These membranes effectively eliminated suspended particles from water, with their performance evaluated against that of commercially available membranes. This research, carried out utilizing the spin-casting technique, outlines a synthesis route for microfiltration membranes tailored to semi-crystalline polymers and their plastic forms.

Towards the Stable Binding of Mercury: Synthesis and Functionalization of Dibenzyldiazabicyclononane Scaffolds

AbstractA universally applicable synthesis route for the preparation of functionalized diazabicyclononane compounds was elaborated starting from a readily available 1,5‐diphenyl‐3,7‐diazabicyclo[3.3.1] nonan‐9‐ol by alkylation of both secondary amines with modified benzyl residues containing a bromo, trimethylstannyl, trimethylsilyl, and pinacolboranyl residue. High yields (65–88 %) were achieved, supporting the intended purpose of these compounds: efficient mercuration reactions to stably bind Hg2+. Finally, the C‐9 position of two functionalized diazabicyclononanes was further modified by introducing an azide functionality. This enables the conjugation to biomolecules of interest via click chemistry combined with a tracking by the introduced mercury isotopes.

Intercalation based synthesis of Chevrel phase superconductors

This work focuses on the superconducting and magnetic properties of Chevrel phase (CP) compounds (Cu2Mo6S8 and Ni2Mo6S8) processed via a novel self-propagating high-temperature synthesis (SHS) method involving ternary cation intercalation in MoS2 high-temperature polymorphs. Green pellets of the precursor materials sealed under vacuum and exposed to 1050 °C or 1200 °C rapidly transformed from a powder mixture into submicron CPs within minutes. X-ray diffraction analysis confirmed the presence of Cu2Mo6S8 CP (67%), and Ni2Mo6S8 (93%). This group has illustrated the first time CP were formed at low energy cost and full stoichiometry. Magnetization versus temperature data obtained for the samples under different field conditions confirmed the superconducting behavior of the Cu–CP at a critical temperature of 8.3 K. The Ni–CP behaved as a superparamagnetic at low temperature (4.2 K). The results of this work suggest that the novel SHS process offers a viable scalable synthesis route for the Chevrel family of compounds and that it is worth exploring the functional applications of the new compounds of this material system.

Green Synthesis of Silver Nanoparticles from Cannabis sativa: Properties, Synthesis, Mechanistic Aspects, and Applications

The increasing global focus on green nanotechnology research has spurred the development of environmentally and biologically safe applications for various nanomaterials. Nanotechnology involves crafting diverse nanoparticles in terms of shapes and sizes, with a particular emphasis on environmentally friendly synthesis routes. Among these, biogenic approaches, including plant-based synthesis, are favored for their safety, simplicity, and sustainability. Silver nanoparticles, in particular, have garnered significant attention due to their exceptional effectiveness, biocompatibility, and eco-friendliness. Cannabis (Cannabis sativa L.) has emerged as a promising candidate for aiding in the green synthesis of silver nanoparticles. Leveraging the phytochemical constituents of Cannabis, researchers have successfully tailored silver nanoparticles for a wide array of applications, spanning from biomedicine to environmental remediation. This review explores the properties, synthesis mechanisms, and applications of silver nanoparticles obtained from Cannabis. Additionally, it delves into the recent advancements in green synthesis techniques and elucidates the optical properties of these nanoparticles. By shedding light on plant-based fabrication methods for silver nanoparticles and their diverse bionanotechnology applications, this review aims to contribute to the growing body of knowledge in the field of green nanotechnology. Through a comprehensive examination of the synthesis processes, mechanistic aspects, and potential applications, this review underscores the importance of sustainable approaches in nanoparticle synthesis and highlights the potential of Cannabis-derived silver nanoparticles in addressing various societal and environmental challenges.

Metal-Organic Frameworks-Based Frustrated Lewis Pairs for Selective Reduction of Nitroolefins to Nitroalkanes.

Nitroalkanes serve as essential intermediates in the synthesis of pharmaceuticals, agrochemicals, and functional materials. To date, nitroalkanes are mainly prepared from homogeneous catalysts such as noble transition metal catalysts with poor recyclability. Herein, we propose a metal-organic framework-frustrated Lewis pair (MOF-FLP) heterogeneous catalyst for selectively reducing nitroolefins to nitroalkanes under moderate reaction conditions. MOF enrichment effect can significantly improve the catalytic efficiency compared to homogeneous FLP catalysts. Benefiting from the strong interaction between FLP and MOF, the MOF-FLP catalyst exhibits outstanding recyclability. This work not only provides a convenient route for nitroalkane synthesis but also showcases the potential of porous heterogeneous FLP catalysts, offering inspiration for future catalytic design strategies.

Advancements in Starch‐Based Aerogels and Hydrogels for Treatment of Water Containing Heavy Metals – A Short Review

AbstractRapid industrialization and profligate use of resources in the present era has led to increase in the concentration of toxic heavy metal ions in water bodies and has become a serious environmental concern. Starch hydrogels and aerogels with engineered functionality, porosity, regeneration characteristics, and high surface to volume ratio have rendered them potential candidates for the adsorption of heavy metal ions from wastewater streams. However, grafting, crosslinking, and composting of the starch aerogels and hydrogels to tailor them in response to various stimuli such as ionic strength, pH, and temperature has added an advantage in the treatment of wastewater containing heavy metal ions. This review critically analyses the various synthesis routes for the production of starch‐based aerogels and hydrogels with physico‐chemical characteristics (amylose content, gelatinization temperature, surface area, density, and porosity) and their applicability to adsorb heavy metal (Cd, Cu, Co, Ni, Cr, Pb, Zn, Fe, and Co) ions from wastewater. Future prospects in the development of economical and robust starch‐based aerogels and hydrogels in terms of their stability and reusability have also been discussed.

The influence of the synthesis route and microwave activation on the CuFe2O4 spinel mixed oxide catalysts activity in N2O decomposition

In this study a comprehensive analysis of the influence of synthesis route of CuFe2O4 spinel mixed oxides on their catalytic performance in the N2O decomposition was carried out. A co-precipitation technique allowed one to obtain the CuFe2O4 spinel with a higher specific surface area and pore volume compared to the synthesis with the application of organic additives. This resulted in better catalytic performance of the CuFe2O4 samples prepared by co-precipitation. The microwave activation step with the duration of 1 min during the co-precipitation synthesis led to the formation of the CuFe2O4 spinel with a higher content of oxygen vacancies per 1 m2 in comparison with the sample obtained without the microwave activation. This fact caused a significantly higher specific activity of the CuFe2O4 spinel synthesized with the application of 1 min microwave activation. The increase of the microwave treatment time led to the fast growth of the contents of the CuO and α-Fe2O3 phases, which are less active in the N2O decomposition, resulting in the activity drop.

Controlling the coverage of intermediates on the active site enables efficient carbon dioxide electroreduction to hydrocarbons

The electrochemical CO2 reduction reaction (ECO2RR) has the capability to convert CO2 molecules into high-value products, offering a feasible pathway aligned with carbon cycling and emission reduction. Nevertheless, significant efforts are required to achieve highly active and selective catalysts tailored for specific products. Herein, a facile synthesis route is proposed, wherein copper, phosphorus, and carbon precursors are mixed and subsequently calcined at different temperatures to obtain a series of copper-based catalysts (CPC-300, 500, 700) containing various copper components with different phases and oxidation states. And further performance tests show their differentiated product distributions. Specifically, CPC-300, which contains more high-valence Cu, is more inclined to produce C2 products, while CPC-700 possessing low-valence Cu as its phase is more keen to produce C1 products. In particular, the CPC-700 catalyst presents a high FECH4 of 52.2 % with a CH4 partial current density of −167.8 mA cm−2 at −1.447 V vs. RHE. Combining the results of in-situ Raman and electrochemical characterizations confirms the effect of valence state and composition on the adsorbed intermediates containing *CO and *H during the reaction. This work achieves the design and development of highly selective and active Cu-based catalysts from the strategies of valence state and component engineering.

Green Synthesis of Silver Nanoparticles Using Plant Extract Blends and Its Impact on Antibacterial and Biological Activity

There is a strong interest in using green resources for synthesizing nanoparticles (NPs) of industrial and biomedical utility in a way to maintain desired material properties throughout use while not inducing any harmful effects. The use of various plant extracts as reducing, capping, or stabilizing agents is widely attempted in green nanotechnology. However, very little has been explored about incorporating plant extract blends into green NP synthesis routes. Here, we used the combination of tea and olive leaf extracts for the synthesis of silver NPs and evaluated the advantages it provided over both chemical and single-plant-mediated synthesis routes. Four different reducing agents (tannic acid, black tea leaves extract, olive leaves extract and their blend) were used to synthesize silver NPs (Ag NP) from silver nitrate (AgNO[Formula: see text]. The synthesized Ag NP was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), and ultraviolet-visible (US-Vis) spectroscopy. The antimicrobial properties of Ag NP were assessed against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus) using the colony-forming unit (CFU) assay and the minimum inhibitory concentration (MIC) assay. The cytotoxic potential of Ag NP on human colorectal adenocarcinoma (Caco-2) cells was assessed by the WST-1 assay. Results showed that Ag NP synthesized using plant extract mixtures had a primary particle size of 40[Formula: see text]nm and were very effective antibacterial agents, with the MIC values ranging from [Formula: see text]g/mL to 10[Formula: see text][Formula: see text]g/mL. While the particle size obtained in chemical synthesis was slightly lower, the resultant Ag NP did not serve as an effective antibacterial agents at low doses. Further understanding of how best to integrate extracts of different plants into green NP synthesis routes will enable wider and safer biomedical applications.

Impact of the electrospinning synthesis route on the structural and electrocatalytic features of the LSCF (La0.6Sr0.4Co0.2Fe0.8O3–δ) perovskite for application in solid oxide fuel cells

In-house electrospun La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF) nanofibers have been tested through synchrotron x-ray diffraction and electrochemical impedance spectroscopy (EIS) in the 823–1173 K range, namely in the operating window of intermediate-temperature solid oxide fuel cells. Identical tests have been carried out on commercial LSCF powders, as a control sample. The results demonstrate that the electrospinning manufacturing procedure influences the crystalline properties of the perovskite. The rhombohedral structure (R), stable at room temperature, is retained by nanofibers throughout the whole temperature range, while a rhombohedral to cubic transition (R→C) is detected in powders at ⁓1023 K as a discontinuity in the rhombohedral angle α, accompanied by an abrupt change in oxygen occupation and microstrain. EIS data have a single trend in the nanofibers Arrhenius plot, and two different ones in powders, separated by a discontinuity at the structural transition temperature. Thus, a striking parallel is demonstrated between the variation with temperature of crystallographic features and electrochemical performance. Interestingly, this parallel is found for both nanofiber and granular electrodes. This opens up questions and new perspectives in attributing activation energies derived from EIS tests of LSCF materials to electrochemical processes and/or crystal structure variations.

The Limited Incorporation and Role of Fluorine in Mn-rich Disordered Rocksalt Cathodes.

Disordered rocksalt oxide (DRX) cathodes are promising candidates for next-generation Co- and Ni-free Li-ion batteries. While fluorine substitution for oxygen has been explored as an avenue to enhance their performance, the amount of fluorine incorporated into the DRX structure is particularly challenging to quantify and impedes our ability to relate fluorination to electrochemical performance. Herein, an experimental-computational method combining 7Li and 19F solid-state nuclear magnetic resonance, and ab initio cluster expansion Monte Carlo simulations, is developed to determine the composition of DRX oxyfluorides. Using this method, the synthesis of Mn- and Ti-containing DRX via standard high temperature sintering and microwave heating is optimized. Further, the upper fluorination limit attainable using each of these two synthesis routes is established for various Mn-rich DRX compounds. A comparison of their electrochemical performance reveals that the capacity and capacity retention mostly depend on the Mn content, while fluorination plays a secondary role.

Recent Developments in the Materials and Miniaturization of Supercapacitors

AbstractHigh‐performing energy storage systems are getting more and more attention due to the rapid growth of renewable energy harvesting technology. To keep pace with it, supercapacitors have emerged a promising energy storage technology providing high power density and long cycle life. In an urge to enhance the energy density without sacrificing the power density, enormous research is going on the exploration of high‐performance electrode materials. Huge modifications in the present synthesis routes and innovations in the new techniques may be attributed to the large‐scale production of potential electrode materials for supercapacitors. This review focuses on the recent advancements in several potential electrode materials for supercapacitors and device miniaturization.

Unravelling the potential of magnetic nanoparticles: a comprehensive review of design and applications in analytical chemistry.

The study of nanoparticles has emerged as a prominent research field, offering a wide range of applications across various disciplines. With their unique physical and chemical properties within the size range of 1-100 nm, nanoparticles have garnered significant attention. Among them, magnetic nanoparticles (MNPs) exemplify promising super-magnetic characteristics, especially in the 10-20 nm size range, making them ideal for swift responses to applied magnetic fields. In this comprehensive review, we focus on MNPs suitable for analytical purposes. We investigate and classify them based on their analytical applications, synthesis routes, and overall utility, providing a detailed literature summary. By exploring a diverse range of MNPs, this review offers valuable insights into their potential application in various analytical scenarios.

Atomically Thin Kagome-Structured Co9Te16 Achieved through Self-Intercalation and Its Flat Band Visualization.

Kagome materials have recently garnered substantial attention due to the intrinsic flat band feature and the stimulated magnetic and spin-related many-body physics. In contrast to their bulk counterparts, two-dimensional (2D) kagome materials feature more distinct kagome bands, beneficial for exploring novel quantum phenomena. Herein, we report the direct synthesis of an ultrathin kagome-structured Co-telluride (Co9Te16) via a molecular beam epitaxy (MBE) route and clarify its formation mechanism from the Co-intercalation in the 1T-CoTe2 layers. More significantly, we unveil the flat band states in the ultrathin Co9Te16 and identify the real-space localization of the flat band states by in situ scanning tunneling microscopy/spectroscopy (STM/STS) combined with first-principles calculations. A ferrimagnetic order is also predicted in kagome-Co9Te16. This work should provide a novel route for the direct synthesis of ultrathin kagome materials via a metal self-intercalation route, which should shed light on the exploration of the intriguing flat band physics in the related systems.

Evaluating the Kinetics and Molecular Mechanism for Biomimetic Metabolic Activation of PAHs by Surface-Enhanced Raman Scattering Spectroscopy.

Biomimetic cytochrome P450 for chemical activation of environmental carcinogens is an efficient in vitro model for evaluating their mutagenicity and ultimately acquiring the metabolites that cannot be easily accessed by conventional routes of organic synthesis. Different kinds of mutagen derived from polyaromatic hydrocarbons (PAHs) by metalloporphyrin/oxidant model systems have been reported, but the underlying molecular mechanisms are poorly understood. Herein, we have for the first time demonstrated an effective surface-enhanced Raman scattering (SERS) protocol to study the dynamics and biomimetic metabolic behaviors of pyrene (Pyr) in the presence of various oxygen donors. Quantitative information on the relative concentration of Pyr and its metabolites in the biomimetic system can be extracted from the SERS spectra. On the basis of our results, we conclude that the oxidative metabolism of Pyr is highly influenced by the types and concentrations of oxygen donors, leading to the formation of 1-hydroxypyrene and dioxygenated products. Besides, the addition of an appropriate amount of an organic solvent can promote the formation of secondary oxidation products. These results offer valuable insights into the dynamics of PAHs metabolism and the regulation of their metabolic pathways in biomimetic activation. In comparison to traditional liquid chromatography-mass spectrometry, the present SERS approach is more suitable for high-throughput evaluation of the metabolic process and kinetics of PAHs. We anticipate that this approach will enable a more general and comprehensive tracking of metabolic dynamics and molecular mechanisms involved in the biomimetic activation of other xenobiotics, such as procarcinogens, promutagens, and drugs.

Core–Shell catalyst particles for tandem catalysis: An experimental/numerical approach towards optimal design

Tandem catalysis is a promising approach to intensify chemical processes and increase their efficiency. On the other hand, the design of efficient, optimal and targeted tailored tandem catalysts is yet so challenging as the optimal catalyst loading is difficult to assess a priori. In this article, we present a concise route towards the design of optimal core–shell tandem catalyst particles on the example of coupled RWGS and FTS reactions for any specific spherical morphology. The route features five consecutive steps including: tandem system identification, catalyst synthesis, i.e. mono- and tandem-functional, catalyst characterization and initial performance test, kinetic modeling with parameter estimation if necessary, and optimal design of catalysts. The initial step features thermodynamic equilibrium calculations for RWGS and FTS showing a common operational window. Then, Pt and Co are selected as active metals and the formulation of the tandem catalyst is designed. For the second step, the synthesis route for the tandem catalyst Pt,CeO2@SiO2-Co, and the mono-functional catalysts, Pt@SiO2 and CeO2@SiO2-Co are presented. For the third step, all catalysts were tested for CO2 hydrogenation as an exemplary tandem process. A reduced transport model from literature was adjusted for RWGS and FTS reactions with kinetic expression from literature to enable numerical optimization. The kinetic parameters are estimated based on the performance tests of the mono-functional reference materials, i.e. Pt@SiO2 for RWGS and CeO2@SiO2-Co for FTS. The model is validated by cross comparison to the data from the tandem reaction setup. In the fifth step, the model was used for the numerical optimization of the catalyst loading on core and shell leading to the identification of the optimal design, resulting in a significant increase of C2+ Yield.

Electrolyte-dependent performance of SnSe nanosheets electrode for supercapacitors

Transition metal chalcogenides (TMC) are widely suggested as electrode materials for electrochemical energy storage devices due to their layered structure. However, the difficult synthesis limits the commercial utilization of these materials. Herein, we report a simple and effective synthesis method to obtain thin films of SnSe electrodes using the solution heating synthesis route. Having an average thickness of 45 nm, the structural and topographical confirmation of the SnSe nanosheets was revealed by XRD, XPS, SEM, and TEM characterizations. The produced SnSe served as electrodes in aqueous three-electrode supercapacitor cells. When tested with KOH electrolyte, it demonstrated a high specific capacitance of 794 F/g and an areal capacitance of 155 mF/cm2 at a scan rate of 5 mV/s. The LiClO4 electrolyte had a specific capacitance of 645 F/g and an areal capacitance of 103 mF/cm2 at a scan rate of 2 mV/s. Furthermore, the SnSe nanosheet electrode maintains 97 % of the maximum capacitance in the LiClO4 electrolyte for 4500 cycles, even at a high scan rate of 100 mV/s. The symmetric solid-state SnSe supercapacitor device fabrication has been carried out by using PVA-KOH and PVA-LiClO4 gel electrolytes. The highest estimated energy density from a fabricated symmetric solid-state (SSC) device is 8.88 Wh/kg at a power density of 2.7 kW/kg. Even at 3.0 kW/kg higher power density, the SSC device retained a reasonably good energy density of 4.3 Wh/kg. Finally, to check the durability of the fabricated SSC device has been carried out for long 5000 CV cycles and the specific capacitance retention was around 96 %. The easy synthesis technique for SnSe nanosheets and binder-free electrode fabrication has a promising application in the production of high-performance energy storage devices. The findings of this study hold significant implications for the advancement of supercapacitor technology, offering insights into the potential of SnSe as a high-performance electrode material and shedding light on the critical role of electrolyte selection in achieving superior supercapacitor performance.

Controllable Regioselective [3+2] Cyclizations of N-CF3 Imidoyl Chlorides and Ph3PNNC: Divergent Synthesis of N-CF3 Triazoles.

Presented herein are two distinct regiodivergent [3+2] cyclization reactions between N-CF3 imidoyl chlorides and N-isocyaniminotriphenylphosphorane (NIITP) that include flexible modulation of the electronic properties of NIITP. The regioselectivity of reactions was different in the absence and presence of the Mo catalyst. The approach provides alternative efficient and scalable routes for N-CF3 triazole synthesis, demonstrating a broad substrate scope, excellent functional group tolerance, and practical advantages.

Effect of surface composition on the stability of Ti- and V-based oxycarbide and oxynitride MXenes

Oxycarbide MXenes were recently experimentally identified, opening up the possibility of a vast majority of carbon-based MXenes synthesised to date being in fact oxycarbides, wherein some substitutional oxygen atoms are present amid the layers that were previously thought to contain carbon only. Here, using an approach based on density-functional theory, we study the structural, energetic and electronic properties of subsurface substitutional oxygen atoms on the X layers of MXenes of the form M2XT2, with M = Ti, V; X = C, N; and T = none, O or F. According to the calculations, subsurface O is thermodynamically stable in any concentration on all the analysed MXenes.Subsurface substitutional O atoms in the Ti2C MXene are thermodynamically driven towards the surface, leaving behind vacancies and creating local O surface terminations. Given that this process involves a very low energy barrier, we predict that, under conditions suitable for eliminating the surface termination of MXenes, many vacancies on the layers of X atoms should occur.The O-terminated carbide MXenes, Ti2CO2 and V2CO2, are stable with their hexagonal symmetry up to a threshold amount of subsurface O, around 75 %, which is above the maximum experimentally observed concentration, 65 %. The F surface termination stabilizes the hexagonal structure of MXenes, which no longer distort regardless of the presence and amount of subsurface oxygen. This suggests that MXene synthesis routes based on fluorine-containing compounds are the most indicated for synthesising nitride MXenes.The PBE functional predicts the semiconductor characteristics of the Ti2CO2 MXene to be lost in the presence of subsurface O, even a percentage as low as 6 %, the lowest considered in this work. The hybrid HSE06 functional predicts the oxycarbide material to remain a semiconductor, but with a significantly lowered band gap energy with increasing substitutional O content. Nevertheless, both functionals agree that the mixture of C and O atoms between the Ti layers of the Ti2CO2 MXene increases its conductivity. To the best of our knowledge, this MXene has never been confirmed experimentally to behave as a semiconductor probably because the real samples of this MXene contain subsurface oxygen.

Nesting BiVO4 nanoislands in ZnO nanodendrites by two-step electrodeposition for efficient solar water splitting

Photoanodes with a large electrochemically active surface area, rapid charge transfer, and broadband light harvesting capacity are required to maximize the photoelectrochemical (PEC) water splitting performance. To address these features, we demonstrate that 3D hierarchal ZnO nanodendrites (NDs) can be sensitized with BiVO4 nanoislands by chemical and thermal treatments of electrodeposited Bi metal films. The flat band measurements and optical characterization suggested that the resulting heterojunction had type-II band alignment with a viable charge transfer from BiVO4 to ZnO NDs. In parallel, PL analysis revealed inhibition of the charge recombination rate by the electron transfer between BiVO4 and ZnO NDs. Upon AM 1.5 G illumination, BiVO4/ZnO NDs heterojunction yielded the highest photocurrent efficiency (0.15 mA·cm−2 at 1.2 V vs. NHE), which was attributed to its enhanced surface area (due to the presence of small dendrite branches), extended broadband light absorption extending from UV to visible light regions, and the most efficient interfacial charge transfer as proven by electrochemical impedance spectroscopy (EIS) studies. Besides, the incident photon-to-current conversion efficiency and applied bias photon-to-current efficiency tests confirmed an improved spectral photoresponse of the heterojunction based photoanode, particularly towards the visible light spectrum. The results outline a promising synthesis route for building heterojunctions between visible light active and wide band gap semiconductors for the use as a highly efficient photoanodes in a PEC cell.