Route For Preparation Research Articles

A High Voltage Sonoelectrochemical Route for Preparation of Highly Oxidized Carbon Nanosheets with Excellent Electrocatalytic Property

A high voltage sonoelectrochemical method was proposed for the preparation of highly oxidized carbon nanosheets (hoCNSs) with good hydrophilicity and excellent electrocatalytic property for various compounds. It was found that the high electrolytic voltage played an important role in the hoCNSs’ fragmentary appearance and excellent electrocatalytic property. The ultrasonic power further obviously improved the electrolytic efficiency. The very low concentration of electrolyte leads to a very simple post-treatment process. So this facile, low-cost and environmentally friendly method had great utility value for the preparation of hoCNSs.

Outstanding microwave absorption behavior and classical magnetism of Y1-K FeO3 honeycomb-like nano powders

Yttrium perovskite ferrite has a stable and symmetrical crystal structure and a simple preparation route. However, it exhibits poor absorption performance at 17–18 GHz. Several studies in the past have reported on the formation of mixed-valence states induced by the addition of monovalent K ions. In this study, YFeO3 was synthesized by doping with monovalent K via the sol-gel auto combustion method. This greatly optimized the wave-absorbing properties and effective bandwidth of YFeO3. The influence of different K additions on the absorption properties of the materials was also studied. All the hybrid composites showed excellent absorbing properties, with Y0.8K0.2FeO3 having an effective bandwidth of 4.88 GHz at a simulated thickness of 2.0 mm, Furthermore, the reflection loss (RL) value of Y0.7K0.3FeO3 reached − 30.56 dB at 15.44 GHz (effective bandwidth up to 4.72 GHz) corresponding to the thickness of only 1.6 mm. This demonstrates that this broadband effect is greater than other similar materials. Moreover, the as-prepared samples completely covered the X and Ku band at only 2.2 mm, and the maximum effective bandwidth reached 5.28 GHz at 2.0 mm. The excellent wave absorption and frequency broadening effects were due to the various loss mechanisms and improved impedance matching characteristics caused by doping.

Hybrid Improper Ferroelectricity: A Theoretical, Computational, and Synthetic Perspective

We review the theoretical, computational, and synthetic literature on hybrid improper ferroelectricity in layered perovskite oxides. Different ferroelectric mechanisms are described and compared, and their elucidation using theory and first-principles calculations is discussed. We also highlight the connections between crystal chemistry and the physical mechanisms of ferroelectricity. The experimental literature on hybrid improper ferroelectrics is surveyed, with a particular emphasis on cation-ordered double perovskites, Ruddlesden–Popper and Dion–Jacobson phases. We discuss preparative routes for synthesizing hybrid improper ferroelectrics in all three families and the conditions under which different phases can be stabilized. Finally, we survey some synthetic opportunities for expanding the family of hybrid improper ferroelectrics.

CHITIN HYDROGEL PREPARED AT VARIOUS TEMPERATURE OF WATER VAPOR–INDUCED PHASE INVERSION

"Chitin solutions were obtained by dissolving chitin extracted from crab shell waste in N,N-dimethylacetamide (DMAc) solvent, in the presence of 5, 7 and 10% lithium chloride (LiCl). Then, the concentrated chitin solution was subjected to water vapor-induced phase inversion to prepare the chitin hydrogel. The properties of the resultant chitin hydrogel having various LiCl concentrations were determined after coagulating at different temperatures of the water vapor, namely, 5, 20 and 60 °C. The viscosity of the chitin solutions decreased when the temperature increased, suggesting the formation of the hydrogel could be accelerated by applying heat. After the chitin solution was coagulated, the resultant hydrogels prepared at higher temperature of water vapor provided better properties than those of the others. When the concentration of LiCl in the hydrogel was 7%, the water content values decreased from 407 to 359%, and the tensile strength increased from 447 to 737 kPa as the temperature was adjusted from 5 to 60 °C, respectively. As for viscoelasticity, the storage modulus of the chitin hydrogels indicated that the increment in the LiCl concentration to 7% and the water-vapor temperature of 60 °C could form a tighter structure of the hydrogels. Considering the green preparation route of the chitin hydrogels and their obtained characteristics, they can be considered as promising materials for applications where such properties required, such as in the biomedical and agricultural sectors."

Innovation new route for preparation of polyacrylamide bearing urethane group based on one-pot Curtius rearrangement

Innovation new route for preparation of polyacrylamide bearing urethane group based on one-pot Curtius rearrangement

Effect of different curing methods on the preparation of carbonized high-titanium slag based geopolymers

This work reported a rapid preparation route of carbonized high titanium slag (CHTS) based geopolymer with better mechanical properties by employing different curing techniques. The combination pre-curing treatment (first thermal heating at 60℃ for 6 h and then microwave radiation at 210 W for 15 min) was confirmed as an effective preparation method, and the compressive strength of the geopolymer reached 76.33 MPa. Mechanism analysis indicated that the facilitating effect of the combination pre-curing process in different reaction stages has resulted in the better formation of hydration gels in geopolymer samples. Thus, a high-quality hydration structure with the lowest porosity and micro-cracks was obtained.

Investigating the effects of synthesis procedures on textural and catalytic properties of nickel/magnesium silicate catalyst in glycerol dry reforming

• The synthesis method affects the structural properties of the Ni/MgO.SiO 2 catalyst. • The structural features of the Ni catalyst affect catalytic performance significantly. • The Ni/MgO.SiO 2 catalyst prepared by one-pot method showed better performance. • The one-pot method has resulted in the highest textural properties of the Ni/MgO.SiO 2. Ni-based catalysts supported on magnesium silicate were synthesized using various synthesis procedures and were then investigated for the first time in the glycerol-DR (dry reforming) process. In general, synthesis procedures for catalyst supports included co-precipitation and hydrothermal, and nickel as active metal was attached to the support simultaneously with support preparing and impregnation technique. The results of characterizations of Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), hydrogen temperature-programmed reduction (TPR-H 2 ), temperature-programmed oxidation (TPO), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) element mapping, Fourier transform infrared (FTIR), thermogravimetric analysis (TGA-DTA), and the catalytic glycerol-DR reaction tests illustrated that the preparation route of Ni/MgO.SiO 2 catalyst is effective in the structural and physicochemical features of the sample. It was observed that the catalysts with various synthesis methods exhibited different activity and stability during the glycerol-DR reaction. However, the highest glycerol conversion (31–50%) and the yield of both H 2 and CO were achieved over the Ni/MgO.SiO 2 (I) catalyst at all reaction temperature ranges (600–750 °C). The high catalytic performance of the Ni/MgO.SiO 2 (I) sample in the glycerol-DR reaction was related to its textural properties such as surface area (411 m 2 g −1 ), the crystallite size (8.5 nm), and active species dispersion, which were superior for this catalyst in comparison with other samples. This sample also exhibited better catalytic stability during the reaction. Furthermore, synthesis gas (syngas) was produced for all catalysts with an H 2 /CO ratio of less than 1.6. These results clearly show a significant impact of the sample synthesis procedure on the catalyst's final physical and chemical properties. The Ni/MgO.SiO 2 catalyst prepared with a one-step method showed high potential as a glycerol-DR catalyst for syngas production.

Synthesis of novel antibacterial and antifungal dithiocarbamate-containing piperazine derivatives via re-engineering multicomponent approach

A metal-free multicomponent synthetic route for the diverse preparation of dithiocarbamate-containing piperazine derivatives was developed through the C–N bond cleavage of DABCO ring. This multicomponent re-engineering approach proceeds via the reaction of amines, CS2 and DABCO salts in one pot. Various DABCO salts and secondary amines are tolerated well in this protocol to afford a broad spectrum of dithiocarbamate-containing piperazines in good to high yields. Then, the selected compounds have been deployed against some critical types of bacteria and fungi. A certain number of synthesized compounds revealed not only appropriate antibacterial activity as investigated by disc fusion and minimum inhibitory concentration methods against bacteria (Gram-positive and Gram-negative), but also depicted good to excellent antifungal activity.

Engineering hierarchical porous S-doped Defective nickel Cobaltite/carbon hybrids to boost efficient asymmetric electrochemical capacitor

Developing energy materials with sufficient active sites, large surface area, high conductivity, and good stability through low-cost preparation routes are vital to the promotion of energy storage technologies. However, it is not easy for the longing component-structure features converged on a single component, the hybrid strategy provides a possible approach for the thorny issue. Herein, micro/mesoporous S–NiCo2O4/AC with abundant vacancy defects is rationally designed via intermolecular bonding of S–NiCo2O4 anchored onto carbon nanosheets through a facile hydrothermal and low-temperature pyrolysis method. The constructed hybrids possess superior structural durability, good electrical conductivity, and rich active sites due to the strong interfacial conjunction and favorable synergistic effect between the porous AC and S–NiCo2O4. Consequently, the S–NiCo2O4/AC hybrid demonstrates high conductivity, reasonable specific surface area, and superior specific capacitance, and the assembled hybrid electrochemical capacitor (S–NiCo2O4/AC//NAC) reveals an ideal energy density of 74.8 Wh kg−1 and power density of 31.4 kW kg−1, which is superior to the reported devices. This work not only paves the strategy toward efficient energy materials but also provides new insight into the relationship between each phase of the hybrids.

Insights into the Role of Biopolymer-Based Xerogels in Biomedical Applications.

Xerogels are advanced, functional, porous materials consisting of ambient, dried, cross-linked polymeric networks. They possess characteristics such as high porosity, great surface area, and an affordable preparation route; they can be prepared from several organic and inorganic precursors for numerous applications. Owing to their desired properties, these materials were found to be suitable for several medical and biomedical applications; the high drug-loading capacity of xerogels and their ability to maintain sustained drug release make them highly desirable for drug delivery applications. As biopolymers and chemical-free materials, they have been also utilized in tissue engineering and regenerative medicine due to their high biocompatibility, non-immunogenicity, and non-cytotoxicity. Biopolymers have the ability to interact, cross-link, and/or trap several active agents, such as antibiotic or natural antimicrobial substances, which is useful in wound dressing and healing applications, and they can also be used to trap antibodies, enzymes, and cells for biosensing and monitoring applications. This review presents, for the first time, an introduction to biopolymeric xerogels, their fabrication approach, and their properties. We present the biological properties that make these materials suitable for many biomedical applications and discuss the most recent works regarding their applications, including drug delivery, wound healing and dressing, tissue scaffolding, and biosensing.

A simple salt mediated electrooxidative method for the synthesis of benzaldehydes from benzyl alcohols

A mild and efficient approach for the electrochemical conversion of benzyl alcohols to benzaldehydes is reported in homogeneous medium using Carbon/Stainless Steel electrodes and NaCl as mediator with H2SO4 as supporting electrolyte. To achieve excellent product conversion, optimization of the reaction condition with various parameters was carried out in a beaker type cell. In 2 F of current density and ambient temperature, benzyl alcohols electrochemically oxidized to benzaldehydes in 90% yield. The present work demonstrates a green and sustainable route for benzaldehydes preparation and the superiority of electrochemical method for organic synthesis.

Green and chemical synthesis of CuO nanoparticles: A comparative study for several in vitro bioactivities and in vivo toxicity in zebrafish embryos

CuO NPs is being applied for various applications including catalyst, electronics, cosmetics, and biomedicines due to its exceptional physicochemical properties. Physical and chemical routes for CuO NPs synthesis raised the concern of environmental hazard due to use of high energy, high temperature, and toxic chemicals. Conversely, green procedure is considered as an inexpensive and eco-friendly approach. To compare in vitro bioactivities and in vivo toxicity, CuO NPs was synthesized by two different methods; green and chemical routes. Leaf extract of a medicinal plant (Salacia reticulate) was used as a reducing and capping agent for green synthesis of CuO NPs. Sodium hydroxide was applied for chemical route of CuO NPs preparation. The in vivo toxicity of both CuO NPs (green and chemical) was examined in zebrafish (Dania rerio) embryos. Several in vitro biological activities e.g. antibacterial, cytotoxicity (in human cells), antidiabetic, and anti-inflammatory activities of both CuO NPs (green and chemical) was also assessed. Prepared CuO NPs (green and chemical) was characterized by SEM-EDX, FTIR, XRD, and UV–Vis spectroscopy. Several biomarkers such as hatching rate, malformation, and mortality rate of zebrafish embryos showed that green prepared CuO NPs exerted much lesser toxicity as compared to chemically synthesized CuO NPs. Antibacterial activity of green CuO NPs against Gram-negative (Escherichia coli, Staphylococcus aureus, and Enterobacter) and Gram-positive (Bacillus subtilis and Pseudomonas aeruginosa) bacteria was higher than chemical CuO NPs. Cytotoxicity results showed that human breast cancer cells (MCF-7) were more sensitive to green CuO NPs than chemical CuO NPs. Furthermore, antidiabetic and anti-inflammatory activities of green CuO NPs was greater than those of chemically prepared CuO NPs. This work revealed that in vitro bioactivities of green synthesized CuO NPs was better than chemically synthesized CuO NPs. Green CuO NPs also displayed higher biocompatibility towards zebrafish than chemical CuO NPs. This work highlights the importance eco-friendly green synthesis of CuO NPs for biomedical applications.

In Situ Anchoring Massive Isolated Pt Atoms at Cationic Vacancies of α‐NixFe1‐x(OH)2 to Regulate the Electronic Structure for Overall Water Splitting

AbstractRational design and preparation of single‐atom catalysts provide a promising strategy to significantly improve the electrocatalytic activity for water splitting. In particular, single atoms anchored at cationic vacancies can enhance the stability of the catalysts and improve reaction kinetics. In this work, Pt single atoms are loaded at layered α‐Ni2/3Fe1/3(OH)2 by oxidizing Fe2+ with H2PtCl6, and specifically, Pt atoms are anchored at in situ generated iron cationic vacancies during the process, resulting in stabilized Pt single atoms in the surface of α‐Ni2/3Fe1/3(OH)2 with the maximum loading of ≈6.15 wt%. The Pt single atoms not only act as active sites for hydrogen evolution reaction but also regulate the electronic structure of NiFe hydroxides and activate Ni atoms adjacent to Pt for oxygen evolution reaction. Therefore, the water‐splitting electrolyzer assembled with such a bifunctional catalyst shows a smaller overpotential than that with RuO2 and 20 wt% Pt/C catalysts as the anode and cathode, respectively, and efficient solar‐to‐hydrogen conversion. The results demonstrate the practical application of single‐atom Pt catalysts with low cost, large loading, and facile preparation route.

Poly(3-hydroxybutyrate) Nanocomposites with Cellulose Nanocrystals.

Poly(3-hydroxybutyrate) (PHB) is one of the most promising substitutes for the petroleum-based polymers used in the packaging and biomedical fields due to its biodegradability, biocompatibility, good stiffness, and strength, along with its good gas-barrier properties. One route to overcome some of the PHB’s weaknesses, such as its slow crystallization, brittleness, modest thermal stability, and low melt strength is the addition of cellulose nanocrystals (CNCs) and the production of PHB/CNCs nanocomposites. Choosing the adequate processing technology for the fabrication of the PHB/CNCs nanocomposites and a suitable surface treatment for the CNCs are key factors in obtaining a good interfacial adhesion, superior thermal stability, and mechanical performances for the resulting nanocomposites. The information provided in this review related to the preparation routes, thermal, mechanical, and barrier properties of the PHB/CNCs nanocomposites may represent a starting point in finding new strategies to reduce the manufacturing costs or to design better technological solutions for the production of these materials at industrial scale. It is outlined in this review that the use of low-value biomass resources in the obtaining of both PHB and CNCs might be a safe track for a circular and bio-based economy. Undoubtedly, the PHB/CNCs nanocomposites will be an important part of a greener future in terms of successful replacement of the conventional plastic materials in many engineering and biomedical applications.

Synthesis and Energetic Properties of Trending Metal‐Free Potential Green Primary Explosives: A Review

AbstractThe requirements for the chemical to act as a primary explosive, its importance, and the hazards associated with heavy‐metal‐based primary explosives are all well‐stated in this review. In addition, it outlined the limitations of the heavy‐metal‐free primary explosives already in use. This analysis underlines the importance of green primary explosives with updated information. It summarizes the possible candidates of metal‐free new generation green primary explosives, including their preparation routes, energetic properties, applications, and comparisons to traditional primary explosives. Furthermore, this analysis also aims to discuss the necessity for metal‐free primary explosives as well as the significant problem of replacing traditional primary explosives.

High‐performance thermoplastic polyureas via a non‐isocyanate route from urea and aliphatic diamines

AbstractPolyureas (PUrs) with excellent properties have been applied widely in many fields. These days attention has been turned to non‐isocyanate routes for PUr preparation due to the toxicity and the high cost of isocyanates. Urea is a green chemcial which can be either from urine or from recycled carbon dioxide and ammonia. Here we introduce a urea‐based route to prepare PUrs, by melt polycondensation of urea and 1,10‐diaminodecane (DA‐10) or/and 1,6‐diaminohexane (DA‐6) without catalyst, solvent, and high pressure. It is difficult to synthesize such thermoplastic PUrs from diisocyanate without any solvent since the melting point of PUr is normally higher than 170°C at which isocyanate is able to react with urea group to form biuret. The thermoplastic PUrs obtained in this study exhibit excellent mechanical and thermal properties. Furthermore, the properties can be adjusted by changing the feed ratio of diamines (DA‐6/DA‐10). The compression‐molded PUrs show even better mechanical properties than ultra‐high molecular weight polyethylene (UHMWPE). The values of Young's modulus, strength at break and elongation at break are found to be 230–300 MPa, 40–60 MPa and 200%–400%, respectively (except for PUr‐6). Therefore, this facile, non‐isocyanate approach provides a viable alternative to the current industrial process for high‐performance PUrs.

Propane dry reforming over highly active NiO-MgO solid solution catalyst for synthesis gas production

In the present study, the textural characteristics and catalytic efficiency of the NiO(x)-MgO solid-solution catalysts (x = 10,15,20, and 25 wt.%) were determined in CO2 reforming of propane. All samples were fabricated by the simple mechanochemical preparation route. The chemicophysical characteristics of the synthesized catalysts were determined using XRD, BET, H2-TPR, TPO, and SEM exams. The obtained results demonstrated that the physicochemical properties and catalytic activity of the samples were affected with the increment in NiO content, which is assigned to the change in the concentration of active sites and improvement of the reduction features. The NiO(25)-MgO catalyst was selected as the sample with the highest activity, and the effect of the operating factors and calcination temperature were studied over this catalyst. Also, the TPO analysis showed that the whisker carbon was formed on the spent catalyst and the sample with 25 wt.% Ni possessed the highest amount of deposited carbon. Moreover, the initial catalytic activity of all catalysts was not changed during 300 min time on stream.

Near-Infrared All-Fused-Ring Nonfullerene Acceptors Achieving an Optimal Efficiency-Cost-Stability Balance in Organic Solar Cells

Near-Infrared All-Fused-Ring Nonfullerene Acceptors Achieving an Optimal Efficiency-Cost-Stability Balance in Organic Solar Cells

Homologous Strategy: Fabrication of a High-Performance Dual-Carbon Potassium Ion Hybrid Capacitor

Potassium ion hybrid capacitors (PIHC) have attracted a significant amount of interest in recent years because of their excellent overall performance and the abundance of potassium resources. The search for kinetically matched and high-performing anode and cathode materials is the key to the development of PIHCs. Hereby, we present a homologous preparation method for dual-carbon electrode materials of PIHCs with the single precursor nitrilotriacetic acid trisodium salt (NTA-3Na) by different preparation routes. The 3NaC-700 obtained by high-temperature calcination as the anode exhibits excellent kinetics performance for potassium ion storage due to its three-dimensional, large layer spacing and N-doped structure. 3NaC can be converted to a 3NaAC cathode with a high specific surface area (SSA, 3014 m2 g–1) and superior capacitance properties by further KOH activation. As a result of the advantages of the 3NaC and 3NaAC electrodes mentioned above, a high-performance dual-carbon PIHC is fabricated. It delivers a high energy and power density of 149.2 Wh kg–1 at 200 W kg–1. A high energy density of 67.2 Wh kg–1 is maintained even at a high power density of 20 kW kg–1. The PIHC device also exhibits excellent cycling stability with 81% capacity retention after 8000 cycles at a current density of 2.0 A g–1.

Green Biosynthesis of Tin Oxide Nanomaterials Mediated by Agro-Waste Cotton Boll Peel Extracts for the Remediation of Environmental Pollutant Dyes.

The sustainable synthesis of metal oxide materials provides an ecofriendly and more exciting approach in the domain of a clean environment. Besides, plant extracts to synthesize nanoparticles have been considered one of the more superior ecofriendly methods. This paper describes the biosynthetic preparation route of three different sizes of tetragonal structure SnO2 nanoparticles (SNPs) from the agro-waste cotton boll peel aqueous extract at 200, 500, and 800 °C for 3 h and represents a low-cost and alternative preparation method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrophotometry, ultraviolet–visible absorption spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy. Surface area and porosity size distribution were identified by nitrogen adsorption–desorption isotherms and Brunauer–Emmett–Teller analysis. The photocatalytic properties of the SNP samples were studied against methylene blue (MB) and methyl orange (MO), and the degradation was evaluated with three different size nanomaterials of 3.97, 8.48, and 13.43 nm. Photocatalytic activities were carried out under a multilamp (125 W Hg lamps) photoreactor. The smallest size sample exhibited the highest MB degradation efficiency within 30 min than the most significant size sample, which lasted 80 min. Similarly, in the case of MO, the smallest sample showed a more superior degradation efficiency with a shorter period (40 min) than the large-size samples (100 min). Therefore, our studies suggested that the developed SNP nanomaterials could be potential, promising photocatalysts against the degradation of industrial effluents.