High-efficiency Synthesis Research Articles

Improving biocatalysis of cefaclor with penicillin acylase immobilized on magnetic nanocrystalline cellulose in deep eutectic solvent based co-solvent

Deep eutectic solvent (DES), has been considered as a new type of green solvent applied in enzymatic systems. Here, we reported DES-buffer co-solvent as a novel reaction medium for high efficient synthesis of cefaclor by penicilin acylase immobilized on magnetic nanocrystalline cellulose. Effect of DES composition, DES-buffer ratio, temperature, pH, substrate ratio and substrate concentration was systematically investigated. In co-solvent consisting of choline chloride (ChCl):glycol-buffer (7:3, v/v), conversion of 7-ACCA was 94%, synthesis to hydrolysis ratio was 1.8, and yield of cefaclor reached 91%, higher than that in aqueous buffer with optimized yield of 84%, showing the great potential of DES as organic solvent alternative. To the best of our knowledge, this is the first example of biosynthesis of cefaclor in the DES-buffer co-solvent.

Low-temperature phyto-synthesis of copper oxide nanosheets: Its catalytic effect and application for colorimetric sensing

The last decade has seen a remarkable detonation in modifying chemical processes for nanomaterial synthesis to make them ‘green’. Owing to the unique properties of nanomaterial and with regard to environmental issues, in this study, a new alternative and fast eco-friendly approach for the synthesis of copper oxide nanosheets (CuO-NSs) using Terminalia catappa (Indian almond) leaf extract as a renewable and non-toxic reducing agent and efficient stabilizer was reported. It is noteworthy to mention that the present fabrication process can open up the possibility of fast, low cost and high efficiency synthesis of CuO nanostructures with an interesting morphology of nanosheets at ambient temperature and pressure. Optimization of important factors such as pH, the quantity of leaf extract, copper precursor concentration, incubation time and temperature on the formation of CuO-NSs were investigated. The formation of bioreduced CuO-NSs was certified by UV–Vis spectroscopy, XRD, TEM analysis and FT-IR spectroscopy. Due to good stability, and excellent catalytic activity of the synthesized CuO-NSs, they are exerted to degrade of MB dye in water as a model color pollutant in the presence of NaBH4 at room temperature. Furthermore, color properties of CuO nanostructures aid us to apply these biosynthesized nanomaterials in the design of optical sensors for detection of Fe2+ and Fe3+ ions. In view of many advantages of the current optical sensors based on CuO-NSs, such as eco-friendly, cost-effective, and straightforward design, the sensing system presents a potential application in environmental science.

Rapid and high yield synthesis of carbon dots with chelating ability derived from acrylamide/chitosan for selective detection of ferrous ions

Rapid and high efficient synthesis of carbon dots is crucial problem for scalable synthesis and practical biomedical or environmental application. However, synthesis of carbon dots still has the challenges, such as long reaction time of hydrothermal carbonization and low synthetic yield of rapid microwave carbonization. To develop rapid and high-yield synthesis of carbon dots, we proposed acrylamide/chitosan boost the synthetic yield of carbon dots via microwave-hydrothermal carbonization. The reaction time and synthesis yield were 30 min and 45.9%, respectively. As increasing of the carbon-carbon double bonds content, the synthetic yield of carbon dots (45.9%) was improved 5.85 and 4.53 times higher than carbon dots derived from chitosan or acrylamide, respectively. Carbon dots with amino and carboxylic groups exhibited the chelating ability benefiting for detection of ferrous ions, and the detection limit for ferrous ions was as low as 160 nM with the concentration range of 0–50 μM. Rapid and high yield synthesis carbon dots derived from acrylamide/chitosan provides carbonaceous probe with chelating ability for detection of ferrous ions sensitively and specifically.

Mass production of poly(ethylene glycol) monooleate-modified core-shell structured upconversion nanoparticles for bio-imaging and photodynamic therapy

Developing robust and high-efficient synthesis approaches has significant importance for the expanded applications of upconversion nanoparticles (UCNPs). Here, we report a high-throughput synthesis strategy to fabricate water-dispersible core-shell structured UCNPs. Firstly, we successfully obtain more than 10 grams core UCNPs with high quality from one-pot reaction using liquid rare-earth precursors. Afterwards, different core-shell structured UCNPs are fabricated by successive layer-by-layer strategy to get enhanced fluorescence property. Finally, the hydrophobic UCNPs are modified with poly(ethylene glycol) monooleate (PEG-OA) though a novel physical grinding method. On the basis of mass-production, we use the as-prepared PEG-UCNPs to construct an 808-nm stimuli photodynamic therapy agent, and apply them in cancer therapy and bio-imaging.

High Efficient Synthesis of Hydroxyl-Terminated Polybutadiene (HTPB) based Polyurethane via Microwave Heating

High Efficient Synthesis of Hydroxyl-Terminated Polybutadiene (HTPB) based Polyurethane via Microwave Heating

Rapid and high efficient synthesis of zeolite W by gel-like-solid phase method

Abstract Zeolite W was synthesized rapidly and efficiently by gel-like-solid phase method using silica-alumina xerogel as the silica-alumina source and potassium hydroxide as the alkali source. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and N2 adsorption-desorption. The results exhibited that zeolite W can be synthesized with silica-alumina gel (n(Al2O3)/n(SiO2) = 0.2) under a wide range of synthesis conditions: n(K2O)/n(SiO2) = 0.125–0.5, n(H2O)/n(SiO2) = 5.55–14.81, crystallization temperature T = 125–150 °C, and crystallization time t = 6–18 h. Among them, a batch of uniform and well crystallized zeolite W was synthesized under 150 °C for 12 h with the mole ratio of n(K2O)/n(SiO2) = 0.375 and n(H2O)/n(SiO2) = 7.40. The specific surface area of optimal sample is 221.98 m2 g−1, and NH4+ exchange capacity in exchange fluid is up to 38.12 mg g−1 and the highest recovery amount of K+ is 51.21 mg g−1 in artificially simulated seawater. The mechanism of zeolite W synthesized by gel-like-solid phase method is liquid-solid two phases transformation mechanism. Compared with the conventional hydrothermal synthesis system, the gel-like-solid phase synthesis method greatly reduced the amount of water, shortened the crystallization time, improved the utilization rate of raw materials and simplified the recovery process of mother liquor.

High-efficiency synthesis of high-performance K0.5Na0.5NbO3 ceramics

Pure (K0.5Na0.5)NbO3 (KNN) ceramics with high density, fine and uniform-size grains were prepared by mechanochemical activation-assisted process. The time of synthesis is only 100 min, which is 72% – 93% shorter than the 6–24 h of the conventional solid-state method. Compared to samples prepared by conventional solid-state method, both the microstructure evolvement and electric properties were explored in detail. Results show the electric properties was significantly improved. Moreover, the dielectric and ferroelectric properties of obtained KNN ceramics exhibit strong dependence on the crystal size of the initial powders. The optimized ceramics HKNN100 showed a quite high energy storage performance, i.e., large electric energy storage density (Wtol = 1.612 J/cm3) and recoverable energy storage density (Wrec = 0.431 J/cm3), which can be mainly ascribed to the large dielectric breakdown strength (DBS = 110 kV/cm). Our works demonstrated that mechanochemical activation-assisted method possesses advantages for high-efficiency preparation of KNN or KNN-based ceramics.

Zn-Co@N-Doped Carbon Derived from ZIFs for High-Efficiency Synthesis of Ethyl Methyl Carbonate: The Formation of ZnO and the Interaction between Co and Zn

In this work, a series of Zn-Co@N-doped carbon materials were prepared by pyrolysis of Co/Zn-ZIF precursors under a N2 atmosphere and used for high-efficiency synthesis of ethyl methyl carbonate (EMC) from dimethyl carbonate (DMC) and diethyl carbonate (DEC). The Co to Zn molar ratio and calcination temperature were varied to study the physical and chemical properties of Zn-Co@N-doped carbon materials identified by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), inductively coupled plasma (ICP), thermogravimetric analysis (TG) and temperature programmed desorption (TPD) analysis. It was deduced that the formation of a ZnO crystalline structure and the interaction between zinc and cobalt providing weak basic sites and strong basic sites, respectively, in different samples significantly affected their catalytic performance. The catalyst activated the reaction most effectively when the Co to Zn molar ratio was 1.0 and calcination temperature was 600 °C. With the DMC to DEC molar ratio controlled at 1:1, a superior yield of around 51.50% of product EMC can be gained over catalyst ZnCo/NC-600 at 100 °C with 1 wt% catalyst loading in 7 h.

High-efficiency synthesis of a naphthalene-diimide-based conjugated polymer using continuous flow technology for organic field-effect transistors

A conjugated polymer based on naphthalene-diimide and dithiophene units was synthesized by continuous flow synthesis.

Nanoporous Glass with Controlled Pore Size for High-Efficiency Synthesis of Oligonucleotides

The results of work on the development of powder nanoporous glass (NPG) with controlled pore size for solid-phase synthesis of oligonucleotides with heightened product yield are presented. NPG with a narrow pore-size distribution was obtained by varying the parameters of the heat and chemical treatment of sodium-borosilicate glasses. It was found that the functional charge of the material is equal to 72 μmol/g. It is shown that using the developed NPG in the synthesis of long-chain oligonucleotides increases the product yield more than seven-fold compared with the analogous material offered on the market.

Synthesis of chrysenosiloles via Mallory photocyclization

Development of synthetic methods for silole-containing or –fused polycyclic aromatic compounds has been in great demand. Described in this paper is an easy synthetic method for the high-efficient synthesis of chrysenosilole derivatives from silatricyclic compounds via the Mallory photocyclization reaction. It is noteworthy that those conventional transition-metal and Lewis acid catalyzed or mediated CC bond coupling reactions did not work well for this aryl-aryl coupling reaction.

Facile synthesis of hierarchical porous carbon nanorods for supercapacitors application

A hierarchical porous carbon nanorods (HPCRs) with highly interconnected three-dimensional conductivity networks derived from metal-organic frameworks have been successfully synthesized via a simple carbonization method. The resultant HPCRs shows an stable porous structure with abundant micro/mesopore on two-dimensional squared shape carbon nanosheets and also between the closely cross-linked carbon sheets. The electrochemical measurements reveal that the HPCRs materials as electrodes for supercapacitor deliver a high specific capacitance of 274 F g−1 at 0.5 A g−1 with an enhanced rate capability in basic media. Moreover, a considerable energy density of 6.77 W h kg−1 at power density of 100 W kg−1 are exhibited for solid-state symmetric supercapacitor. The assembled symmetric supercapacitor also works well under 0 and −20 °C with a remarkable temperature endurance. The large-scale production of unique hierarchical porous carbon nanorods with high efficiency, low cost and one-step synthesis method will be effective electrode materials in energy storage applications.

High efficiency synthesis of HKUST-1 under mild conditions with high BET surface area and CO2 uptake capacity

This study focuses on the development of a hydrothermal method for the rapid synthesis of good quality copper benzene-1,3,5-tricarboxylate (referred to as HKUST-1) with high yield under mild preparation conditions to address the issues associated with reported methods. Different synthesis conditions and activation methods were studied to understand their influence on the properties of HKUST-1. It was found that mixing the precursors at 50 °C for 3 h followed by activation via methanol refluxing led to the formation of a product with the highest BET specific surface area of 1615 m2/g and a high yield of 84.1%. The XRD and SEM data illustrated that the product was highly crystalline. The sample was also tested on its capacity in CO2 adsorption. The results showed strong correlation between surface area of the sample and its CO2 uptake at 1 bar and 27 °C. The HKUST-1 prepared in this study demonstrated a high CO2 uptake capacity of 4.2 mmol/g. It is therefore concluded that this novel and efficient method can be used in the rapid preparation of HKUST-1 with high surface area and CO2 uptake capacity.

SÍNTESIS DE NANOESTRUCTURAS DE CARBONO A PARTIR DE ISOPROPANOL Y ACETATO DE ETILO APLICANDO PRINCIPIOS DE QUÍMICA VERDE

Multiwall carbon nanotubes were grown on a stainless steel AISI 304 core catalyst by chemical vapor deposition in a quartz reactor. The highlight of this research is the use of stainless steel catalyst and organic precursors from renewable feedback for high efficient carbon nanostructures synthesis using green chemistry principles. Isopropanol and ethyl acetate were performing as precursors in the chemical vapor deposition. Raman spectroscopy and electron microscopy were used to analyze the morphology and crystallinity of the synthesized nanostructures. Transmission electron microscopy performed on samples confirms the presence of multiwall carbon nanotubes and metallic particles found on the tip, base and inside the nanotubes demonstrating a mixed growth mechanism. The secondary products found in the samples were carbon nanobars with different interplanar spaces. XRD confirmed the characteristic planes for hexagonal graphite and weak iron and manganese oxides signals. EDS showed a carbon content above 94% and low metals and oxygen contribution. The carbon nanostructures crystallite sizes were calculated from XRD data and compared with the transmission electron microscopy micrographs; the structures obtained from ethyl acetate had major crystallinity. An easy to scale up carbon nanostructures synthesis method applying green chemistry principles is proposed.

Single atom accelerates ammonia photosynthesis

Atomically dispersed metal has gained much attention because of the new opportunities they offer in catalysis. However, it is still crucial to understand the mechanism of single-atom catalysis at molecular level for expanding them to other more difficult catalytic reactions, such as ammonia synthesis from nitrogen. In fact, developing ammonia synthesis under ambient conditions to overcome the high energy consumption in well-established Haber-Bosch process has fascinated scientists for many years. Herein, we demonstrate that single Cu atom yields facile valence-electron isolation from the conjugated π electron cloud of p-CN. Electron spin resonance measurements reveal that these isolated valence electrons can be easily excited to generate free electrons under photo-illumination, thus inducing high efficient photo-induced ammonia synthesis under ambient conditions. The NH3 producing rate of copper modified carbon nitride (Cu-CN) reached 186 μmol g−1 h−1 under visible light irradiation with the quantum efficiency achieved 1.01% at 420 nm monochromatic light. This finding surely offers a model to open up a new vista for the ammonia synthesis at gentle conditions. The introduction of single atom to isolate the valence electron also represents a new paradigm for many other photocatalytic reactions, since the most photoinduced processes have been successfully exploited sharing the same origin.

High-purity helical carbon nanotubes by trace-water-assisted chemical vapor deposition: Large-scale synthesis and growth mechanism

Helical carbon nanotubes (HCNTs) are highly desirable due to their unique geometrical elegance and inherent physical properties; however, high-efficiency synthesis of high-purity HCNTs with high yield and full elucidation of their growth mechanism remains challenging. Traditional methods to achieve the high-yield growth of HCNTs mainly focus on controlling the size of catalytic particles. Herein, we found that addition of trace water greatly benefits large-scale synthesis of HCNTs. Uniform HCNTs with ∼ 100% purity can be obtained, and the yield of HCNTs can reach ∼ 8,078% in a run of 6 h, much higher than that obtained without trace water and any of the reported yields. Experiments and theoretical simulations are performed to reveal that the trace water can react with the dangling bond on carbon, thus inhibiting the generation of amorphous species. Furthermore, the trace water can enhance the anisotropy of the catalyst surface. This results in different segregation rates of carbon atoms coming out of different crystal planes and further periodic mismatch of the graphite layers, thus leading to the formation of HCNTs. Therefore, this new and efficient method is promising for practical, large-scale production of HCNTs.

Simultaneously efficient adsorption and photocatalytic degradation of tetracycline by Fe-based MOFs

Recently, Fe-based metal–organic frameworks (MOFs) have attracted increasing attention and been widely used. To date, however, it is unknown whether they can be employed to degrade tetracycline, one of the most widely used antibiotics. This work therefore aims to provide such support by comparing the performance of three Fe-based MOFs (namely, Fe-MIL-101, Fe-MIL-100, and Fe-MIL-53) in removing tetracycline. Experimental results showed that Fe-MIL-101 exhibited the best performance in tetracycline removal, with 96.6% of tetracycline being removed (initial tetracycline concentration at 50 mg/L) while Fe-MIL-100 and Fe-MIL-53 removed 57.4% and 40.6% under the same conditions. Additionally, the effects of adding dosage, adsorption time, and initial concentration of tetracycline on degradation efficiency were examined. It was found that the adsorption and photocatalytic degradation effect was better with the increase of time, the optimum dosage of Fe-MIL-101 was 0.5 g/L and the removal efficiency decreased with the increasing of initial tetracycline concentrations. Moreover, the trapping experiments and ESR tests indicated that O2−, OH and h+ were the main active species in photocatalytic degradation process of tetracycline. Due to its high removal efficiency and simple synthesis, it could be used as a potential catalyst for degradation of tetracycline and other antibiotics.

Synthesis of benzocycloalkene derivatives via Pd-catalyzed one-pot two-step reactions of benzocyclic ketones, tosylhydrazide with aryl bromides

A new method for the synthesis of benzocycloalkene derivatives is described, through the palladium-catalyzed one-pot two-step reactions of benzocyclic ketones, tosylhydrazide with aryl bromides. Palladium-carbene complex as an important intermediate undergoes migratory insertion to form benzylpalladium complex, followed by a fast β-hydride elimination to give substituted benzocycloalkenes. The advantages of this reaction include readily available starting materials, broad substrate scope, high efficiency, and gram scale synthesis.

One step synthesis of high efficiency nickel/mesoporous TiO2 hybrid catalyst for hydrogen evolution reaction

Nickel-TiO2 hybrid catalysts are synthesized by electrodeposition and their catalytic activity with respect to the hydrogen evolution reaction is analyzed. Two types of titanium oxide particles, which are commercial particles of dense TiO2 and mesoporous TiO2 particles synthesized by an aerosol method, are incorporated into the matrix of the nickel catalyst. Both nickel catalysts containing TiO2 particles presented higher catalytic activity than the conventional nickel Watts catalyst. Mesoporous TiO2-modified nickel catalyst showed the highest catalytic activity towards HER in alkaline medium. In addition, this type of nickel catalyst increases its catalytic activity after ageing treatment, which is an indication of an increase in the electro-active area of the electrode.

Bta-miR-2411 attenuates bovine viral diarrhea virus replication via directly suppressing Pelota protein in Madin-Darby bovine kidney cells

MicroRNAs (miRNAs) are endogenous ∼22 nt noncoding RNAs that control the translation initiation and stability of target genes in a sequence-specific manner and, thus, play important regulatory roles in animals and plants. Homologs of Dom34, called Pelota or PELO, are broadly conserved in eukaryotes and archaea. Biochemical and genetic studies indicate that eukaryotic Dom34/Pelota plays an important role in cell division, differentiation of germline stem cells, and stem cell self-renewal by controlling the expression of specific genes at the translational level. Additionally, it is reported that Pelota is specifically required for high efficiency synthesis of proteins in numerous viruses. In earlier studies, we found the Bos taurus bta-miR-2411 (shortly miR-2411 herein) was significantly upregulated by more than 2.1 times in bovine viral diarrhea virus (BVDV) strain NADL-infected Madin-Darby bovine kidney (MDBK) cells after 8 h post-infection (pi) compared to normal MDBK cells without BVDV infection. Moreover, miR-2411 overexpression significantly reduced the BVDV E1 mRNA level and viral titer. Nevertheless, the mechanisms of miR-2411 attenuating on viral replication remain unclear. Here, we report that miR-2411 as a novel microRNA regulates BVDV NADL replication via directly targeting the Pelota gene in MDBK cells. We investigated whether the potential target sequences of miR-2411, located in the Pelota 3′UTR, and miR-2411 agomir transfection attenuated Pelota mRNA and protein levels. Indeed, upon miR-2411 overexpression, BVDV NADL replication was prevented. Importantly, BVDV NADL replication levels were reversed to normal levels as a result of the Pelota rescuing experiment even though miR-2411 was existent. Overall, we profiled the unique role of miR-2411 in regulating BVDV NADL replication and provided a novel strategy for generalized inhibition of viral infection.