One-step Synthesis Route Research Articles

One-step facile pathway synthesis of PAPXD/1214-PEA thermoplastic elastomer: Structure and properties

In this study, a novel and facile one-step synthesis route was conducted to prepare semi-aromatic polyamide elastomer (PAPXD/1214-PEA) with p-phenylenediamine, dodecane diamine, dodecanedioic acid and polyether amine (PEA) as monomers. A systematic investigation has been conducted into the effect of hard segment content on the thermal, mechanical and solvent resistance of polymers when semi-aromatic polyamides are used as hard segments. It was found that the melting point of the copolymers gradually increased from 191.2 °C to 231.5 °C with the hard segment content increased from 39 % to 76 %, while the Vicat softening temperature (VST) enhanced from 103.2 °C to 192.2 °C. Compared with the commercial polyamide elastomer Pebax@ (produced by Arkema Inc) with similar hard segment contents, the VST of PAPXD14/1214-PEA were 17.4–66.2 °C higher. The mechanical performance of these elastomers was also largely improved with tensile strength increasing from 15.1 to 40.6 MPa, Young's modulus from 28.2 to 168.7 MPa, toughness from 91.1 to 170.7 MJ/m3. In addition, the solvent resistance properties of PAPXD14/1214-PEA was compared with the commercial polyamide elastomer Pebax@. After soaking in hydrochloric acid for 24 h, the tensile strength of PAPXD/1214-PEA with the hard segment content increased from 50 % to 63 % decreased down to 9.4 and 14.4 MPa, respectively. While the commercial polyamide elastomer Pebax@ (with similar hard segment content) decreased down to 1.5 and 4.3 MPa, indicating the commercial polyamide elastomer products were deteriorated. This suggests the corrosion resistance of the synthesized PAPXD/1214-PEA is much better than that of commercial product, and these semi-aromatic polyamide elastomers can be potentially applied in some harsh service environment especially for high temperature and corrosion sealing.

Comparison of lithium sources on the electrochemical performance of LiNi0.5Mn1.5O4 cathode materials for lithium-ion batteries

In order to fulfill the demand for high energy and capacity, an electrode with high-voltage capability, namely LiNi0.5Mn1.5O4 (LNMO) that has an operating potential of up to 4.7 V vs Li/Li+, is currently becoming popular in Li-ion battery chemistries. This research produced LNMO by using a solid-state method with only one-step synthesis route to compare its electrochemical performance with different lithium sources, including hydroxide (LNMO-LiOH), acetate (LNMO-LiAce), and carbonate (LNMO-LiCar) precursors. TGA/DSC was first performed for all three sample precursors to ensure the optimal calcination temperature, while XRD and SEM characterized the physical properties. The electrochemical measurements, including cyclic voltammetry and charge-discharge, were conducted in the half-cell configurations of LNMO//Li-metal using a standard 1 M LiPF6 electrolyte. LNMO-LiOH samples exhibited the highest purity and the smallest particle size, with values of 93.3% and 418 nm, respectively. In contrast, samples with higher impurities, such as LNMO-LiCar, mainly in the form of LixNi1-xO (LiNiO), displayed the largest particle size. The highest working voltage possessed by LNMO-LiOH samples was 4.735 V vs Li/Li+. The results showed that LNMO samples with LiNiO impurities would affect the reaction behavior that occurs at the cathode-electrolyte interface during the release of lithium-ions, resulting in high resistance at the battery operations and decreasing the specific capacity of the LNMO during discharging. The highest value, shown by LNMO-LiOH, was up to 92.75 mAh/g. On the other side, LNMO-LiCar only possessed a specific capacity of 44.57 mAh/g, indicating a significant impact of different lithium sources in the overall performances of LNMO cathode.

Cu2Mg5Sn5Se16 – the first selenospinel of the A2B5C5X16 type

Abstract A new member of the A2B5C5X16 family of compounds – the first one containing Se – has been synthesized. Following a one-step mechanochemical synthesis route, starting from the binary selenides and Mg metal, Cu2Mg5Sn5Se16 has been obtained. Structural evaluation was carried out using X-ray diffraction with subsequent Rietveld refinement. Cu2Mg5Sn5Se16 adopts the spinel type with space group Fd 3 ‾ $\overline{3}$ m and exhibits a statistical distribution of Cu, Mg, and Sn on Wyckoff position 16d whereas Wyckoff position 8a is only occupied by Mg. Despite the fact that structures containing MgSe4 tetrahedra are rare in the literature, it appeared to be the most plausible way of distributing the cations in this compound.

One-step synthesis of δ-MnO2 with rich defects for efficient ozone decomposition under humid conditions

The catalytic performance of manganese oxides (MnOx) for ozone (O3) decomposition is affected by moisture and stability, for which MnOx with abundant defects offers a promising solution. In this study, a simple and mild one-step synthesis route was developed for highly defective δ-MnO2 preparation. The optimal catalyst was operated at 35 % relative humidity (RH) for 12 h, and the O3 conversion maintained over 99 %. Characterizations revealed that the K+ insertion into the interlayers preserved a highly defective layered structure. Rich surface defects and grain boundaries facilitated the generation of oxygen vacancies and the migration of oxygen species, stabilizing the elimination of O3. In addition, a combination of characterization and experiments determined that physisorbed water is critical for inhibiting activity, and thus, weak physisorption of water on the catalyst represents excellent water resistance. This work aims to provide guidance and new insights into the design of stable and water-resistant MnOx catalysts.

Energy transfer from Ce3+ to Eu3+ in the spinel structure of ZnAl2O4 phosphor for optoelectronic applications

Zinc aluminate (ZnAl2O4), with a spinel structure is known for its versatile applications as catalyst, ceramic material, and optoelectronic device. ZnAl2O4 is an excellent host for trivalent rare-earth ions such as Dy3+ , Tb3+, Eu3+ and Sm3+ has been extensively investigated for application in display devices. The focus of this work is on Ce3+ and Eu3+ co-dopants aiming to address issues such as multistage combustion synthesis routes, the formation of secondary phases, that often impact luminescence intensity. Through a systematic approach, we synthesized the ZnAl2O4 host with consistent cerium concentration and varying europium ions using one-step combustion synthesis route. The findings reveal that the synthesized material exhibits efficient energy transfer, mitigates concentration quenching and demonstrates favorable color chromaticity. The crystal structure analysis confirms phase purity and addresses concerns related to secondary phase formation. The simplified and cost-effective approach of one-step combustion synthesis method for synthesizing Ce3+ and Eu3+ co-doped ZnAl2O4 suggests that this phosphor has potential applications in ultraviolet photo-electronic technology and other opto-electronic devices.

Biomimetic synthesis of single-crystalline anhydrous xanthine nanoplates in an aqueous solution with high reflectivity.

Biogenic purine crystals can function in vision as light scatters, mirrors, and multilayer reflectors and produce structural colors or depolarization for camouflage. Xanthine crystals form irregular multifocal mirrors in the median ocellus of Archaeognatha. It is important to broaden the study of crystallization strategies to obtain organic crystals with purine rings in the laboratory. In this work, a facile one-step synthesis route to fabricate bio-inspired xanthine crystals is reported for the first time. The obtained rhomboidal xanthine nanoplates have similar morphology and size to biogenic xanthine crystals. Their length and thickness are about 2-4 μm and 50 nm, respectively. Lattice parameters, crystal structure, formation mechanism and optical properties of synthetic single-crystalline xanthine nanoplates were investigated in detail in this work. The obtained xanthine nanoplate crystals are proposed to be anhydrous xanthine with monoclinic symmetry, and the xanthine nanoplates mainly expose the (100) plane. It is proposed that the anhydrous xanthine nanoplates are formed via an amorphous xanthine intermediate precursor. The synthetic anhydrous xanthine nanoplates exhibit excellent optical properties, including high diffuse reflectivity, strong depolarization and pearlescent luster. This work provides a new design to synthesize bio-inspired organic molecular crystals with excellent optical properties.

Single Crystalline α-Fe2O3 Nanosheets with Improved PEC Performance for Water Splitting.

We report the photoelectrochemical (PEC) performance of a densely grown single crystalline hematite (α-Fe2O3) nanosheet photoanode for water splitting. Unlike expensive ITO/FTO substrates, the sheets were grown on a piece of pure Fe through controlled thermal oxidation, which is a facile low cost and one-step synthesis route. The sheets grow with a widest surface parallel to basal plane (0001). Iron oxide formed on Fe consisting of layer structure α-Fe2O3-Fe3O4-Fe is elucidated from GIXRD and correlated to spectral features observed in Raman and UV-vis spectroscopy. The top α-Fe2O3 nanosheet layer serves as a photoanode, whereas the conducting Fe3O4 layer serves to transport photogenerated electrons to the counter electrode through its back contact. Time-resolved photoluminescence (TRPL) measurements revealed significantly prolonged carrier lifetime compared to that of bulk. Compared to the thin film of α-Fe2O3 grown on the FTO substrate, ∼3 times higher photocurrent density (0.33 mA cm-2 at 1.23 VRHE) was achieved in the nanosheet sample under solar simulated AM 1.5 G illumination. The sample shows a bandgap of 2.1 eV and n-type conductivity with carrier density 9.59 × 1017 cm-3. Electrochemical impedance spectroscopy (EIS) measurements reveal enhanced charge transport properties. The results suggest that nanosheets synthesized by the simple method yield far better PEC performance than the thin film on the FTO substrate. The anodic shifts of flat band potential, delayed electron-hole recombination, and growth direction parallel to the highly conducting basal plane (0001) being some of the contributing factors to the higher photocurrent observed in the NS photoanode are discussed. Characterizations carried out before and after the PEC reaction show excellent stability of the nanosheets in an alkaline electrochemical environment.

Biogenic one-step synthesis of silver nanoparticles using Quisqualis indica linn flower extract: Characterization, molecular docking, and DFT studies

The present study reports a one-step, eco-friendly, and green synthesis route of silver nanoparticles (AgNPs) from the flower extract of Quisqualis indica Linn. Analytical techniques like Ultraviole-visible (UV–Vis), Field emission scanning electron microscope (FESEM), and X-ray diffraction (XRD) were used to investigate different physicochemical characteristics of AgNPs. The UV–Vis spectrum revealed the maximum absorption at 455 nm and FESEM images confirmed that the synthesis produces stable, polydisperse with a spherical, rod-shaped, triangular, and hexagon shape. XRD analysis at 2θ degrees of 38.1o, 44.3o, 64.7o, and 77.7o corresponding to the (111), (200), (220), and (311) planes, respectively, Bragg’s reflections of the face-centered cubic crystalline structure. Fourier transform infrared spectroscopy (FTIR) analysis suggested that the carbonyl and alcoholic groups of the different compounds of the extract of Quisqualis indica Linn flowers were majorly responsible for being the stabilizer and a capping agent of AgNPs. Furthermore, the quantum chemical parameters of β-Sitosterol (1), Brinzolamide (2), Gallic Acid (3), L-Asparagine (4), L-Proline (5), Quisqualic Acid (6), Quinoline-4-Carbonitrile (7), Quercetin (8), and Rutin (9) compounds present in the flowers of Quisqualis indica Linn are also calculated based on density functional theory (DFT). In silico study, a method such as molecular docking was carried out to determine the binding affinity of compounds (1–9) with presentations of Gram-positive bacteria (PDB ID: 2MLM) and Gram-negative bacteria (PDB ID-1KZN). Compounds (1), (2), (7) and (8) had a better score of binding toward the selected proteins. Overall, our findings shed light on the green synthesis of silver nanoparticles and it could be a potential candidate for the pharmaceutical industry against topical pathogens.

Photochemical Synthesis of Porous Triazine-/Heptazine-Based Carbon Nitride Homojunction for Efficient Overall Water Splitting.

Porous triazine-/heptazine-based carbon nitride (THCN) homojunction with chloride (Cl) doping was synthesized by a simple, one-step photochemical synthesis route for efficient visible-light-driven overall water splitting. The phase ratio of triazine-based carbon nitride (TCN) and heptazine-based carbon nitride (HCN), texture and morphology of the THCN isotype junction were finely tuned by varying ultraviolet irradiation time and washing solvents. After washing with acetonitrile, the resulting porous THCN nanosheets with 48 h irradiation contain 21 wt % TCN and 79 wt % HCN units and reveal a significantly improved photocatalytic performance with H2 and O2 production rates up to 7.9 and 4.2 μmol h-1 , respectively, about 3.8 times higher than that of THCN prepared by 36 h illumination. The dual-phase interaction, holey structure, and Cl dopants favor the exposure of active sites, extended visible-light harvesting, accelerated charge transfer, and enhanced photoreduction ability, thereby improving photocatalytic activity.

Adsorption properties and mechanism of zinc acrylic carbon nanosphere aggregates for perfluorooctanoic acid from aqueous solution

This study found that the cross-linkable zinc acrylic nanosphere aggregates (NAs) as precursors were successfully prepared by a simple one-step synthesis route, and Zn,O dopped-carbon nanocomposites were obtained through temperature-controllable engineering, which showed excellent adsorption capacities for perfluorooctanoic acid (PFOA). A series of experiments were performed to investigate and compare carbon materials for the efficient removal of PFOA. The maximum adsorption capacities of PFOA absorbed on carbon nanospheres aggregates (CNAs) were calculated by the Langmuir (360.98 mg/g) and Sips models (309.65 mg/g). The kinetic model indicated there was chemical adsorption and physical adsorption in the adsorption process. Van der Waals force and electrostatic interactions might be the dominant mechanism of the adsorption process. Additionally, pore-filling also played a role in the adsorption process. Furthermore, the adsorption efficiency was still above 90% after five cycles. The selective adsorption ability was tested through various pollutants (metal ions and dye solutions) absorbed by the CNAs. Our results proved that carbon nanosphere aggregates (CNAs) are expected to be outstanding adsorption materials for the decontamination of PFOA from wastewater.

Conditioning of simulated cesium radionuclides in NaOH-activated fly ash-based geopolymers

The growing nuclear safety concerns call for better solutions than traditional Portland cement-based materials to retain radionuclides especially Cesium (Cs). This work explored engineering process development and characterization of low-cost sustainable NaOH-activated fly ash-based geopolymers (FA-GP) as a conditioning matrix for non-radioactive equivalent of Cs (133Cs+). The effects of processing parameters on the FA-GP microstructure, porosity, in-situ zeolite crystallization, and Cs immobilization performance (quantified as the Leachability Index LX) were investigated and compared with literature data. The immobilization of non-radioactive equivalent of Cs (133Cs+) in NaOH-activated FA-GP was investigated using factorial design of experiments. The Cs leachability index (LX) was evaluated according to ANSI/ANS-16.1. FA-GP were characterized using SEM, XRD, and N2 adsorption-desorption isotherms. The results revealed that the main factors influencing Cs immobilization were the curing temperature and the interaction between Cs dosage and curing temperature. LX ≥12 and effective diffusion coefficient De ≤10−12 cm2/s was obtained for FA-GP cured at 90 °C. The effective diffusivity was about 5–7 orders of magnitude lower than for the conventional Portland cement-based encapsulation materials. Enhanced immobilization of Cs (LX = 14.6, De = 2.5 × 10−15 cm2/s), not reported hitherto, was further achieved by in-situ pollucite (Cs,Na)2Al2Si4O12.2H2O crystallization within FA-GP via one-step synthesis route at 90 °C. In addition, leaching studies on powdered FA-GP demonstrated encouraging performance and reliability of FA-GP under extreme mechanical conditions. It therefore appears that FA-GP could be a promising nuclear waste immobilization material, especially for the waste containing high concentration of Cs.

Microwave-Assisted Solvothermal Route for One-Step Synthesis of Pure Phase Bismuth Ferrite Microflowers with Improved Magnetic and Dielectric Properties.

The prototypical plum-free, one-phase multiferric ferrite BiFeO3 (BFO) is solid, parallel, with a high ferroelectric Curie temperature and Neel temperature and antiferromagnetic and ferroelectric propagation. This work aims to synthesize pure-phase BFO in the quickest possible way. We followed the microwave-assisted solvothermal (MWAST) method to achieve pure-phase BFO in the shortest duration of 3 min. The experiment involves simple optimizations with KOH concentration and microwave power levels. The surface morphology along with magnetic properties of BFO synthesized via the MWAST method are altered with varying KOH concentrations and microwave (MW) power levels. Our X-ray diffraction findings reveal that the pure-phase BFO is formed at 800 W MW power, and the structural characterizations like transmission electron microscopy, field emission scanning electron microscopy with energy-dispersive X-ray analysis have displayed the formation of uniformly distributed spherical microflowers of pure-phase BFO exhibiting a single-crystalline nature. Besides, the magnetic measurements affirmed a reliable weak ferromagnetic behavior (magnetization ∼1.25 emu/g) in BFO synthesized at 800 W MW power. In addition, good dielectric behavior with low dielectric loss was accompanied by frequency-dependent dielectric studies indicating an excellent frequency response of the material, and also the room-temperature ferroelectric properties were studied using a ferroelectric analyzer. The polarization of pure-phase BFO increases with the applied electric field and exhibits unsaturated polarization–electric field loops due to leakage current. Moreover, the Fourier transform infrared spectrum of the synthesized material has indicated the pure-phase BFO, and the Raman data have elucidated the vibrational modes of BFO. Further, the analysis of X-ray photoelectron spectroscopy data has confirmed the presence of fewer Fe2+ ions and oxygen vacancies in the pure-phase BFO. Therefore, the collective characterizations and detailed analysis of BFO material have revealed the uniqueness of the MWAST method in producing the pure-phase BFO in 3 min with improved magnetic and dielectric properties, and hence the BFO synthesized via the MWAST method can be a potential candidate for multiferroic applications.

New 18β-Glycyrrhetinic Acid-Emodin Esters Synthetized by a One-Step Innovative Route, Its Structural Characterization, and in Vivo Toxicity Assessed on Zebrafish Models.

To integrate the active advantages of 18β-glycyrrhetinic acid (18β-GA) and emodin, improve bioavailability, increase efficiency, and reduce toxicity, a one-step innovative synthetic route was set up for the first time: 4-dimethylaminopyridine (DMAP) was used as catalyst, 1-ethyl-(3-dimethylaminopropyl)carboimide hydrochloride (EDCI) as condensation agent, dry dichloromethane (DCM) as solvent at 25 °C for 12 h, the three target products were obtained and purified by high performance liquid chromatography (HPLC), the chemical structures of them were characterized by nuclear magnetic resonance (NMR) technique and high resolution electron ionization mass spectrometry (HREI-MS), namely, 18β-glycyrrhetinic acid-3-emodin ester (1, yield 78.83 %, known), di-18β-glycyrrhetinic acid-1-emodin ester (2, yield 6.49 %, new), and di-18β-glycyrrhetinic acid-8-emodin ester (3, yield 1.81 %, new). To estimate their effects of the products on toxicity in zebrafish embryos and juvenile fishes, the two precursors and three target products were assayed involving in hatching rate, survival rate, morphology, heart rate, and apoptosis of cardiomyocytes. The results showed that the target products enhanced the hatching and survival rate of zebrafish embryos, decreased the malformation rate and the apoptosis of cardiomyocytes. It should be suggested that the one-step synthesis route with high yield makes the industrial application of the target products possible due to significantly reduced toxicity. The two new by-products provide potential candidates for the applications of pharmaceutical industry in the future.

Physical and Electrochemical Properties of Graphene Decorated with ZnO Hollow Spheres for Supercapacitor Applications

Single-layer graphene-ZnO hollow sphere (SLG-ZnO(HS)) composites were successfully prepared through facile one-step solvothermal synthesis route. The morphological structures of the samples were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Hollow spheres consisting of ZnO nanoparticles with a diameter of approximately 30 nm are decorated to both sides of the SLG sheets. The electrochemical performances were tested by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance (EIS). The SLG-ZnO(HS) composite electrode synthesized at a concentration of 0.25 mM Zn precursor exhibited an enhanced specific capacitance of 34.7 F/g at a scan rate of 1 mV/s with energy and power densities of 5.39 W h/kg and 1.73 kW/kg, respectively.

One‐Step Formation of Hybrid Nanocrystal Gels: Deposition of Metal Domains on CdSe/CdS Nanorod and Nanoplatelet Networks (Advanced Optical Materials 17/2021)

In article number 2100291, Nadja C. Bigall and co-workers report a one-step synthesis route to prepare different hybrid semiconductor–metal nanocrystal gel networks. The novel approach includes the simultaneous formation of the hyperbranched semiconductor dot-in-rod and nanoplatelet backbones as well as their decoration with noble metals and transition metal-based domains without using light, heat, or any external chemical trigger. The conduction band/Fermi level offset facilitates an efficient charge carrier separation upon illumination in the hybrid gel structures.

Synthesis of Co–Ni and Cu–Ni based-catalysts for dry reforming of methane as potential components for SOFC anodes

In this work, we report a comparative study of Ni-based anode compositions, made of Cu and Co (40 and 80 mol%) and gadolinia-doped ceria (CGO) matrices, for application the dry reforming of methane (DRM) reaction using Solid Oxide Fuel Cells (SOFCs). The new compositions are synthesized by a one-step synthesis route, using citric acid as chelating agent, and characterized at three different stages: i) after synthesis, ii) after reduction, and iii) after DRM. X-ray diffraction (XRD) analysis combined with thermodynamic calculations is used to understand phase evolution along the different stages, revealing that complete solid solutions of NiCo- and NiCu-based alloys are formed after DRM reaction. Transmission Electron Microscopy (TEM) shows the formation of nanocrystalline powders, while surface area (SBET) measurements show higher values in the case of the NiCo-based samples. Moreover, the Co-containing compositions exhibit higher reducibility and stronger metal-ceramic interactions than the Cu-containing samples, according to the Temperature Programmed Reduction (TPR) results. Finally, DRM results demonstrate higher CO2 and CH4 conversions in the case of the Co-containing samples, as well as increased resistance towards carbon deposition, as confirmed by Thermogravimetric and Differential Scanning Calorimetry analyses (TG-DSC). Overall, the Co-based compositions are highly beneficial for their use as anodes for the CO2 reforming of methane in SOFCs.

SIMULTANEOUS ELECTROCHEMICAL DETECTION OF ASCORBIC ACID, DOPAMINE, AND URIC ACID AT MAGNETIC NANOPARTICLES/REDUCED GRAPHENE OXIDE MODIFIED ELECTRODE

A magnetic nanoparticles/reduced graphene oxide modified glassy carbon electrode (MNP/rGO/GCE) was fabricated via one-step facile synthesis route for the simultaneous determination of ascorbic acid (AA), dopamine (DA), along with uric acid (UA). A series of diseases and disorders has been associated with irregular levels of these respective analytes, thus early detection is highly crucial. Physical and electrochemical characterization of the modified electrode was conducted by using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) analysis, X-Ray Diffraction (XRD) analysis and Brauneur-Emmet-Teller (BET), Cyclic Voltammetry (CV) and Electron Impedance Spectroscopy (EIS). The results obtained confirmed the formation of MNP/rGO composite. Differential pulse voltammetry (DPV) of MNP/rGO/GCE displays three well-defined peaks which associated to AA, DA and UA, respectively. The response towards DA is linear in the concentration range of 15 nM to 100 µM with a detection limit of 0.19 nM while a response to AA and UA is also linear in the concentration range of 10 µM to 100 µM with a limit of detection 0.22 µM and 45 nM respectively. The proposed modified electrode offers a good response towards simultaneous detection of three different electroactive species with excellent electron transfer rate, great capacitance and ideal diffusive control behavior.

Facile Preparation of a Laponite/PVA Mixed Matrix Membrane for Efficient and Sustainable Pervaporative Dehydration of C1-C3 Alcohols.

The exfoliation method was applied for the preparation of high-water selective mixed matrix membranes (MMMs), especially for the dehydration of C1–C3 alcohol–water solutions. Herein, a facile and easy method was employed to fabricate physically cross-linked Laponite nanosilicate clay–PVA MMMs without additional cross-linking by a one-step synthesis route for water dehydration from methanol, ethanol, and isopropanol aqueous solutions. The morphologies, chemical structures, thermal stabilities, and surface hydrophilicity of Laponite–PVA MMMs were investigated properly by different characterization techniques. The Laponite concentration has affected the fractional free volume of the membranes, as proven by positron annihilation lifetime spectroscopy analysis. The MMMs displayed both a significant improvement in the separation factor and remarkable enhancement in the permeation fluxes for the three alcohol systems. The influence of the operating temperature on the MMM performance was investigated for the methanol/water solution. The methanol permeability was 100-fold lower than that of the water, indicating that the membranes are more water selective. Particularly, the Laponite–PVA membrane with 5 mg/mL Laponite loading exhibits excellent separation efficiency for C1–C3 dehydration having water permeabilities higher than most other polymeric membranes from the other literature studies of 2.82, 2.08, and 1.56 mg m–1 h–1 kPa–1 for methanol, ethanol, and isopropanol/water systems, respectively. This membrane development allows a more efficient and sustainable separation of aqueous alcoholic mixtures.

Catalytic combustion of CO over Cu-doped iron oxides: CO2 effects on activity

This study reports the catalytic combustion application of FeCuOx thin films synthesized through a doping strategy with different Fe/Cu molar ratios via one-step synthesis route. Structure analysis of the as-prepared thin film reveals the formation of single-phase delafossite structure. A smooth hollows film surface with agglomerated grains was observed. With the introduction of Cu content, Cu+ was successfully embedded in Fe2O3 lattice to form substituted structure, whereas the ratio of OLatt/OAds tended to increase. The perceived behavior was ascribed to the progressive incorporation of Cu, which brought structural changes favoring the formation of anionic vacancies and the mobility of oxygen. The catalytic activity was investigated through the complete catalytic combustion of CO with a high GHSV of 184,500 mL·g−1·h−1, which is closer to actual engineering for the commercial application of the catalytic combustion. The addition of higher quantity of Cu transferred the conversion curvature toward lower temperatures, due to active Cu, Fe and surface oxygen species. Moreover, the effects of CO2 interaction on the reaction mixture was analyzed in order to assess the performance of thin film catalysts under realistic conditions of reaction. Although the principal inhibitor effect was associated with the CO2, the progressive introduction of CO2 in the reaction, gave rise to a decrease of the CO conversion. Furthermore, theoretical calculations based on DFT method of CO with CO2 oxidation over CuFeO2 delafossite film surface catalyst demonstrated that the existence of CO2 acted as an inhibitor in the CO adsorption process which led the reaction to higher temperature.

Synthesis and electrochemical study of coinage metal nanodendrites for hydrogen evolution reaction

Herein, we report a facile one-step synthesis route to fabricate the coinage metal nanodendrites (NDs) via a tailored galvanic replacement reaction (GRR). Cu, Ag and Au NDs are directly grown on glassy carbon plate (GCP) from the mixture of their precursor solutions and Zn dust. The formed NDs are uniformly distributed to the substrate and obtained the unique structures with sharp tips and tertiary branches. The electrocatalytic activity of the synthesized NDs towards the hydrogen evolution reaction (HER) is further investigated in 0.5 M H2SO4 using linear sweep voltammetry (LSV) and the Tafel slope. The results demonstrate that the nanodendrites formed through the GRR process exhibit greater catalytical activity towards HER in comparison to the polycrystalline Cu, Ag and Au. The prepared Au NDs exhibits the highest catalytic performance with a current density of −10.68 mA cm−2 at overpotential of 67 mV and a low Tafel slope of 65 mV dec−1. The simple and easy synthesis approach, the unique morphology and high electrocatalytic activity and excellent stability make the developed Cu, Ag and Au NDs highly efficient catalysts for green energy and electrochemical applications.