Step Synthesis Method Research Articles

Construction of Metal-Organic Framework as a Novel Platform for Ratiometric Determination of Cyanide.

Metal-organic frameworks (MOFs) are frequently utilized as sensing materials. Unfortunately, the low conductivity of MOFs hinder their further application in electrochemical determination. To overcome this limitation, a novel modification strategy for MOFs was proposed, establishing an electrochemical determination method for cyanides in Baijiu. Co and Ni were synergistically used as the metal active centers, with meso-Tetra(4-carboxyphenyl)porphine (TCPP) and Ferrocenecarboxylic acid (Fc-COOH) serving as the main ligands, synthesizing Ni/Co-MOF-TCPP-Fc through a hydrothermal method. The prepared MOF exhibited improved conductivity and stable ratio signals, enabling rapid and sensitive determination of cyanides. The screen-printed carbon electrodes (SPCE) were suitable for in situ and real-time determination of cyanide by electrochemical sensors due to their portability, low cost, and ease of mass production. A logarithmic linear response in the range of 0.196~44 ng/mL was demonstrated by this method, and the limit of detection (LOD) was 0.052 ng/mL. Compared with other methods, the sensor was constructed by a one-step synthesis method, which greatly simplifies the analysis process, and the determination time required was only 4 min. During natural cyanide determinations, recommended readouts match well with GC-MS with less than 5.9% relative error. Moreover, this electrochemical sensor presented a promising method for assessing the safety of cyanides in Baijiu.

The synthesis of amide bond by a simple one-step method to connect ionic liquid and MIL-101-NH2 firmly for efficient CO2 cycloaddition

Finding robust combination modes between ionic liquids and MOFs is still a challenge. In this work, using a simple one step-synthesis method, the ionic liquid was grafted onto MOF without any additives, and the binding mode of the two was characterized by means of XPS, FT-IR, TGA, SEM etc. It was found that the carboxyl group in the ionic liquid bonded with the amino group in MOF to form an amide bond. Thus, a novel stable composite material MIL-101-NH2-1-carboxypropyl-3-methylimidazolium bromine (1-C-3-M@MIL-101-NH2) was synthesized. This composite employed as a catalyst for CO2 cycloaddition demonstrated excellent catalytic activity, achieving a target product PC (Propylene carbonate) yield of 91.7 % under the conditions of 80 °C, 1.0 MPa, and a reaction time of 4 h, without the addition of any co-catalysts or solvents. The good catalytic activity was benefit from the synergistic effect of Lewis acidic Cr centers and nucleophilic Br-, as well as the high specific surface area and good CO2 affinity of 1-C-3-M@MIL-101-NH2. In addition, owing to this robust bonding configuration, the catalyst can be recycled up to five times without losing activity. It is a potential catalyst for CO2 capture and conversion.

Transforming scalable synthesis of graphene aerosol gel material toward highly flexible and wide-temperature tolerant printed micro-supercapacitors

The ever-growing demand for portable, bendable, twistable, and wearable microelectronics operating in a wide temperature range has stimulated an immense interest in the development of solid-state flexible energy storage devices using scalable fabrication technology. Herein, we developed additively manufactured graphene aerosol gel-based all-solid-state micro-supercapacitors (MSCs) via inkjet printing with functioning temperature in the range from −15 to +70 °C and exhibiting a super-stable and reliable electrochemical performance using interdigitated finger electrodes and PVA/H3PO4 solid-state electrolyte. The graphene aerosol gel was obtained using a scalable single step synthesis method from a gas phase precursor using a detonation process, producing a nanoscale shell type structure. The fabricated graphene aerosol gel-based solid-state MSC achieved a volumetric capacitance of 376.63 mF cm−3 (areal capacitance of 76.23 μF cm−2) at a constant current of 0.25 μA and demonstrated exceptional cyclic stability (∼99.6% of capacitance retention) over 10 000 cycles. To exploit the mechanical strength of the as-fabricated graphene aerosol gel-based solid-state MSC, its supercapacitive performance was scrutinized under various bending and twisting angles and the results showed excellent mechanical flexibility. Furthermore, to study the electrochemical performance of the as-fabricated graphene aerosol gel solid-state MSC in stringent surroundings, a broad temperature dependent supercapacitive analysis was performed as stated above. The electrochemical results of the as-fabricated graphene aerosol gel based all-solid-state MSC exhibit a highly potential route to develop scalable and authentic future miniaturized energy storage devices for IoT based smart electronic appliances.

Influence of low level of non-metal doping on g-C3N4 performance for H2 production from water under solar light irradiation

In this paper, a facile one step synthesis method for the preparation of C-, B-, P- and S-doped g-C3N4 by incorporation of small concentration of doping element precursor into urea during thermal polycondensation is reported leading to much lower doping levels than the ones usually reported. The as-obtained doped g-C3N4 photocatalytic materials are deeply characterized in terms of structural, morphological, surface and optical properties. Doping yields beneficial surface morphology modulation along with improved optical, electronic and photocatalytic properties. In particular, C-doped and S-doped g-C3N4 show, after deposition of gold nanoparticles (<1 wt%), enhanced photocatalytic performance (at least twice as high as the undoped photocatalyst, to achieve ca. 610 μmol/h/g) for the production of H2 by water splitting under solar light in the presence of low content (1 vol%) of triethanolamine (TEOA) as sacrificial agent. The most remarkable activity results from the incorporation of traces of S dopant, mainly inserted into interplanar hollow cavities. The enhanced activity is attributed to a combination of high surface area, location of the S dopant and small size of the co-catalyst NPs, which induces enhanced visible light harvesting, enhanced charge carrier separation and enhanced proton recombination. This work highlights the benefits of the optimized low-level doping strategy to overcome the main limitations of g–C3N4–based photocatalysts.

(Digital Presentation) Synthesis of Fluorescent Carbon Nanoparticles (CNPs) By Microwave-Assisted Polymerization of Sp-Carbon Rich Precursors

Carbon nanoparticles (CNPs) have emerged as one of the most promising nanomaterials due to their distinct optoelectronic properties for a diverse range of applications. These unique properties arise from the network of hybridized sp2 carbon atoms as it allows delocalization of the electrons over the entire surface of the molecule. These surface groups help CNPs emit strong fluorescence in visible region. The significant fluorescence of CNPs combined with low toxicity, and photostability makes them suitable for various applications in biosensing, bio-imaging, and OLEDs. Despite several advantages and unique properties, the transformation from laboratory to industrial products has been slow for carbon nanoparticles. The synthetic methods reported until now chemically inert nanoparticles, increasing the difficulty to modulate their morphological, optical, and electronic properties. The organic synthesis methods for synthesizing CNPs often involve several synthesis steps, long reaction time, low yield, non-scalable and inefficient purification methods. Most of these synthesis methods involve several catalysts and removal of catalysts is always a challenge. Resulting nanoparticles also need functionalization using another synthesis step to give them properties such as fluorescence and making them soluble. Therefore, a synthesis method with minimum steps, minimum catalysts which could result in soluble and fluorescence nanoparticles is desired.This work investigates the use of highly reactive sp-carbon rich precursors for polymerization with microwave heating with minimum use of catalysts resulting in fluorescent CNPs. The sp-carbon rich precursors such as TMS-Benzene, butadiyne and acetylene were used as starting material. These alkynes are highly reactive and reacts to other alkynes present in the system in the presence of heat and form polyyne intermediates which are thermodynamically unstable in the form of long chains and decompose to provide us with CNPs. The plan is to use the high reactivity with microwave heating for polymerization without catalysts and further investigate the use of oxidants or minimum catalysts to increase the rate of polymerization and conversion into CNPs. The resulting nanoparticles required minimum purification in centrifuge and were isolated easily as there were no catalysts involved. The resulting nanoparticles were characterized with various techniques to study the morphology, structure, composition, and optical properties of CNPs. The resulting nanoparticles had blue fluorescence under the UV lamp. The single step synthesis of blue fluorescence CNPs was performed with microwave assisted polymerization of sp-carbon rich precursors without any catalysts. Further investigation of this method will provide a single step synthesis method for fluorescent CNPs which would be suitable for application in sensing and OLEDs.

Enhancement of Ce doped La–Mn oxides for the selective catalytic reduction of NOx with NH3 and SO2 and/or H2O resistance

• A–bit doping is more favorable for improving SCR activity than that of B–bit doping. • A–bit doping enhances SO 2 resistance, but B–bit doping improves N 2 selectivity. • A–bit or B–bit doping can form the perovskite structure but the exposed plane changes. • A–bit doping increases Mn 4+ content but B–bit doping decreases Mn 4+ content. Cerium modified La–Mn oxides for NH 3 –SCR at low temperature is prepared by one–step synthesis method and characterized. The results showed that the perovskite La–Mn oxides at A–bit doped by Ce is more favorable for NOx removal than B–bit doping and achieves about 80% conversion of NOx at 120°C and about 100% in the range temperature of 180–220°C as well as good SO 2 and/or H 2 O resistance. However, LaMn 0.8 Ce 0.2 O 3 (B–bit doping) has better N 2 selectivity than La 0.8 Ce 0.2 MnO 3 (A–bit doping) and LaMnO 3 . The generated N 2 O and NO 2 influence the N 2 selectivity in the NH 3 –SCR reaction, but N 2 O is from the NH 3 oxidation while NO 2 is from the NO oxidation. The perovskite La–Mn oxides at A–bit or B–bit doped by Ce are able to maintain the perovskite structure of LaMnO 3.15 but the exposed plane shifts from (104) to (110). However, for both doped samples, some CeOx and Mn 3 O 4 are spilled out from the perovskite structure of La–Mn oxides. A–bit ions doped by Ce can increase Mn 4+ relative content, specific surface area, available oxygen and surface acid amount, while B–bit doping decreases Mn 4+ relative content and adsorbed oxygen and increases Ce 4+ relative content. After SO 2 resistance testing, the formation of (NH 4 ) 2 SO 4 and MnSO 4 on all catalysts is inevitable, but the binding force of the formed metal sulfate is different on catalyst surface, resulting in the difference of its resistance to sulfur.

Synthesis, Characterization and Biocompatibility of Holmium Zirconate/Zinc Sulphide Nanocomposite in Albino Mice in a Gender Specific Manner

Aim of this study was to report the biocompatibility of Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (HO2Zr2O7/ZnS) nanocomposite in albino mice. Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (Ho2Zr2O7/ZnS) nanocomposite were synthesized by, normal microemulsion, chemical co-precipitation and two step synthesis method, respectively. The synthesized materials were characterized by X-ray diffraction (XRD) for the confirmation of phase while scanning electron microscopy (SEM) was used morphological analysis. The composition and the particle size distribution were confirmed by energy dispersive spectroscopy and particle size analysis respectively. Seven week old mice were divided into two groups in a gender specific manner: control group that were intraperitoneally injected with saline solution and treated group were administered with 50 mg/ml solvent/Kg body weight of Holmium zirconate/zinc sulphide nanocomposite for 22 days. A series of neurological tests, blood cell count, selected serum parameters and biomarkers of oxidative stress were analysed in vital organs of both treatments. It was observed that nanocomposite treated female mice remained mobile (P = 0.05) for longer time while both male (P = 0.03) and female (P = 0.02) mice had more rotations than saline treated mice during open field test. Nanocomposite treated male had reduced stretch attend reflex during light dark box test. Blood and serum parameters remained unaffected (P ˃ 0.05) when compared between nanocomposite treated and untreated mice of both genders. Malondialdehyde concentration was significantly elevated (P = 0.04) in liver of male while superoxide dismutase concentrations were significantly reduced (P = 0.05) in brain of female albino mice treated with nanocomposite than their respective control groups.

Synthesis, Characterization and Biocompatibility of Holmium Zirconate/Zinc Sulphide Nanocomposite in Albino Mice in a Gender Specific Manner

Aim of this study was to report the biocompatibility of Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (HO2Zr2O7/ZnS) nanocomposite in albino mice. Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (Ho2Zr2O7/ZnS) nanocomposite were synthesized by, normal microemulsion, chemical co-precipitation and two step synthesis method, respectively. The synthesized materials were characterized by X-ray diffraction (XRD) for the confirmation of phase while scanning electron microscopy (SEM) was used morphological analysis. The composition and the particle size distribution were confirmed by energy dispersive spectroscopy and particle size analysis respectively. Seven week old mice were divided into two groups in a gender specific manner: control group that were intraperitoneally injected with saline solution and treated group were administered with 50 mg/ml solvent/Kg body weight of Holmium zirconate/zinc sulphide nanocomposite for 22 days. A series of neurological tests, blood cell count, selected serum parameters and biomarkers of oxidative stress were analysed in vital organs of both treatments. It was observed that nanocomposite treated female mice remained mobile (P = 0.05) for longer time while both male (P = 0.03) and female (P = 0.02) mice had more rotations than saline treated mice during open field test. Nanocomposite treated male had reduced stretch attend reflex during light dark box test. Blood and serum parameters remained unaffected (P ˃ 0.05) when compared between nanocomposite treated and untreated mice of both genders. Malondialdehyde concentration was significantly elevated (P = 0.04) in liver of male while superoxide dismutase concentrations were significantly reduced (P = 0.05) in brain of female albino mice treated with nanocomposite than their respective control groups.

Synthesis, Characterization and Biocompatibility of Holmium Zirconate/Zinc Sulphide Nanocomposite in Albino Mice in a Gender Specific Manner

Aim of this study was to report the biocompatibility of Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (HO2Zr2O7/ZnS) nanocomposite in albino mice. Holmium zirconate, zinc sulphide and holmium zirconate/zinc sulphide (Ho2Zr2O7/ZnS) nanocomposite were synthesized by, normal microemulsion, chemical co-precipitation and two step synthesis method, respectively. The synthesized materials were characterized by X-ray diffraction (XRD) for the confirmation of phase while scanning electron microscopy (SEM) was used morphological analysis. The composition and the particle size distribution were confirmed by energy dispersive spectroscopy and particle size analysis respectively. Seven week old mice were divided into two groups in a gender specific manner: control group that were intraperitoneally injected with saline solution and treated group were administered with 50 mg/ml solvent/Kg body weight of Holmium zirconate/zinc sulphide nanocomposite for 22 days. A series of neurological tests, blood cell count, selected serum parameters and biomarkers of oxidative stress were analysed in vital organs of both treatments. It was observed that nanocomposite treated female mice remained mobile (P = 0.05) for longer time while both male (P = 0.03) and female (P = 0.02) mice had more rotations than saline treated mice during open field test. Nanocomposite treated male had reduced stretch attend reflex during light dark box test. Blood and serum parameters remained unaffected (P ˃ 0.05) when compared between nanocomposite treated and untreated mice of both genders. Malondialdehyde concentration was significantly elevated (P = 0.04) in liver of male while superoxide dismutase concentrations were significantly reduced (P = 0.05) in brain of female albino mice treated with nanocomposite than their respective control groups.

A simple study on vaporization enthalpy of taurine anion-based ionic liquid

Room temperature ionic liquids, as a new type of environmentally friendly “green solvents”, have many well-known and unique properties, which lay the foundation for their wide application in many fields. Two target products, 1-propyl-3-methylimidazolium taurine ionic liquid and 1- butyl −3- methylimidazolium taurine ionic liquid, were synthesized by conventional two - step synthesis method. Hydrogen and carbon NMR spectra were also used to verify the chemical structure of the target products. Isothermal thermogravimetric analysis was used to record the decreasing trend of the weight for two ionic liquids samples over time. According to Langmuir equation and Clausius-Clapeyron equation, vaporization enthalpies of two ionic liquids were obtained. For the study of thermodynamic properties, the vaporization enthalpy data of ionic liquid in a certain temperature range are very important and indispensable.

Uniform Chiral Gap Synthesis for High Dissymmetry Factor in Single Plasmonic Gold Nanoparticle.

Synthesis of chiral plasmonic materials has been highlighted for the last decades with their optical properties and versatile potential applications. Recently reported aqueous-based amino acid- and peptide-directed synthesis of chiral plasmonic gold nanoparticles with 432 point-group symmetry shows exceptionally high chiroptic response within 100 nm scales. Despite its already excellent chiroptic response, a single-nanoparticle dark field scattering study revealed that full chiroptic potential of chiral gold nanoparticle is limited with its overall synthetic uniformity. Based on this knowledge, we present a multi-chirality-evolution step synthesis method for the enhancement of chiroptic response through an increase in particle uniformity. Detailed time variant study and interrelationship study of reaction parameters allowed the systematic construction of design principles for chiral nanoparticles with exceptional chiroptic response. With the application of precisely controlled growth kinetic to two distinct growth regimes, modified chiral gold nanoparticles showed significantly improved uniformity, achieving an improved dissymmetry factor of g = 0.31. We expect that our strategy will aid in precise morphology and property control for chiral nanomaterials, which can be used in various plasmonic metamaterial applications.

One Step Synthesis of Sr2Fe1.3Co0.2Mo0.5O6−δ-Gd0.1Ce0.9O2−δ for Symmetrical Solid Oxide Fuel Cells

Homogenous distribution of individual phases in the composite electrode is critical to the overall electrode performance. In this work, we report a one-step synthesis method to fabricate Sr2Fe1.3Co0.2Mo0.5O6−δ-Gd0.1Ce0.9O2−δ (SFCM-GDC) composite electrode material for symmetrical solid oxide fuel cells (SSOFCs). X-ray diffraction analysis reveals that the characteristic peaks of the perovskite and fluorite phases are obtained in the SFCM-GDC powder via the one-step synthesis method without any observable impurities. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) indicate a better phase distribution of the composite electrode of SFCM-GDC via one-step synthesis than that via a mechanically mixing process. As a result, the area specific resistance (ASR) of SFCM-GDC electrode is effectively decreased to 0.036 Ω cm2 and 0.047 Ω cm2 at 850 oC in air and hydrogen, respectively, compared to that of 0.041 Ω cm2 and 0.074 Ω cm2 of the mechanically mixed SFCM and GDC (SFCM+GDC). The maximum power density of a cell with configuration of SFCM-GDC∥LSGM∥SFCM-GDC can reach 0.986 W cm−2, higher than that with mechanically mixed electrode of 0.894 W cm−2 at 800 °C. This work shows that one step synthesis method is an effective way to fabricate composite electrode with enhanced electrode performance.

19P - Silymarin functionalized quantum cores as selective inhibitor of polo-like kinase 1, and preclinical antitumor activity in human breast cancer xenografts

BackgroundPolo-like kinase 1 (PLK1) is a protein kinase plays an important role in the initiation, maintenance, and completion of mitotic process. Human PLK1 has been shown to be over-expressed in a variety of human cancers, and elevated levels of PLK1 have been associated with poor prediction, leading to an attractive target for anticancer therapy. MethodsA novel Silymarin functionalized FeO quantum cores (SiFeO QDs) were synthesized through one step synthesis method. For in vitro assay MTT, apoptotic staining assays and cell cycle analysis were performed. In vivo studies, xenocraft mice further administration of the SiFeO QDs at a dose of 25mg/kg body weight every other day for 14d. after 24h of the last treatment dose, the mice were left to monitor their survival or sacrificed to assess the antitumor activity. ResultsSiFeO QDs inhibited proliferation of Triple negative breast cancer cell lines, with mean inhibitory concentration of (IC50) value about 4.5µg/ml, meanwhile in non-dividing normal cells, it didn’t exhibit any adverse effects upto 50µg/ml. In animal models, administration of SiFeO QDs significantly inhibited the growth of MM2 breast cancer xenografts. It also accompanied by decreased expression of anti-apoptotic proteins, BCL-2, and MCL-1 and increased expression of BAX. Moreover, caspase-3 was activated to a greater extent after SiFeO QDs treatment. Impressively the treated group animal exihibit there is no aberrant effect in vital organs and blood parameters. Tumor growth was significantly inhibited after i.v. injection of SiFeO QDs at dose of 5mg/kg compared to free FeO QDs at dose of 25mg/kg. However, this system remarkably suppressed tumor growth in human breast cancer xenografts. ConclusionsThe significant antitumor efficacy of SiFeO QDs were attributed to the ability of the cores to show both prolonged blood circulation and high accumulation in tumors, as confirmed by near infrared (NIR) imaging systems. Taken all together, the SiFeO QDs hold great potential in biomedical applications especially cancer theranostics due to their versatile nature in therapy as well in diagnostics in clinical tumor biology. Legal entity responsible for the studyManickam Paulpandi. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Structure and electric properties of zink oxide−based ceramics doped with iron

The structure and electrical properties of (FexOy)10 (ZnO)90 ceramics (0 ≤ x ≤ 3; 1 ≤ y ≤ 4) synthesized in air by one− and two−stage method were studied. To dope ZnO, powders of FeO, α−Fe2O3, and Fe3O4 or a mixture (α−Fe2O3 + FeO) were used. On the basis of X−ray diffraction analysis, gamma−resonance spectroscopy and Raman spectroscopy, it was established that at fixed average iron concentrations of 1—3 at.% in ceramic samples, at least three phases are formed: solid solution Zn1−δFeδO with wurtzite structure and residual iron oxides FexOy, used as doping agents. Scanning electron microscopy and energy−dispersive X−ray analysis have shown that, in the studied ceramics, the grain sizes of the wurtzite phase decreased from several tens of micrometers using one−step synthesis to the submicron level for the case of two−step synthesis. It was found that the incorporation of iron into ZnO leads to a contraction of the crystal lattice in the wurtzite phase and the stronger, the higher the proportion of oxygen in the doping iron oxides FexOy. The study of the temperature dependences of the electrical resistivity have shown that deep donor centers with an activation energy of about 0.35 eV are formed in the wurtzite phase Zn1−δFeδO. The temperature dependences of the electrical resistivity in the undoped ZnO in the temperature range of 6—300 K and in the doped ceramics (FexOy)10(ZnO)90, obtained by the one−step synthesis method, at temperatures below 50 K, are characterized by a variable activation energy, which indicates a strong disordering of their structure.

Facile one step synthesis method of spinel LiMn2O4 cathode material for lithium batteries

This study succeeded to prepare three pure phases of Mn2O3, Mn3O4 beside one of the best cathode materials, spinel LiMn2O4. LiMn2O4 with high phase purity and crystallinity was synthesized by a facile, cost effective and one step synthesis method. The structure and morphology of the powders were studied in detail by means of X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) and surface area. The X-ray diffraction shows that the post-annealing process reveals the formation of pure crystalline spinel LiMn2O4 with small particle size and lower lattice strain. The thermogravimetric analysis threw the light on the role of the evaporation technique in producing LiMn2O4 by following the different phases on the thermal performance of the precursor. The morphological characterization shows the clear appearance of the octahedral particles of LiMn2O4 calcined at high temperature with microporous nanosized structure. Electrochemical testing of the as prepared spinel at 900 °C showed promising results in terms of high initial capacity and good cycle stability. The as prepared spinel sample shows also good rate performance.

Synthesis and biological evaluation of novel tris-chalcones as potent carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase and α-glycosidase inhibitors

A novel class of fluoro-substituted tris-chalcones derivatives (5a-5i) was synthesized from phloroglucinol and corresponding benzaldehydes. A three step synthesis method was followed for the production of these tris-chalcone compounds. The structures of the newly synthesized compounds (5a-5i) were confirmed on the basis of IR, 1H NMR, 13C NMR, and elemental analysis.The compounds’ inhibitory activities were tested against human carbonic anhydrase I and II isoenzymes (hCA I and hCA II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly). These chalcone derivatives had Ki values in the range of 19.58–78.73 nM for hCA I, 12.23–41.70 nM for hCA II, 1.09–6.84 nM for AChE, 8.30–32.30 nM for BChE and 0.93 ± 0.20–18.53 ± 5.06 nM against α-glycosidase. These results strongly support the promising nature of the tris-chalcone scaffold as selective carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase, and α-glycosidase inhibitor. Overall, due to these derivatives’ inhibitory potential on the tested enzymes, they are promising drug candidates for the treatment of diseases like glaucoma, leukemia, epilepsy; Alzheimer’s disease; type-2 diabetes mellitus that are associated with high enzymatic activity of carbonic anhydrase, acetylcholine esterase, butyrylcholinesterase, and α-glycosidase.

One-step synthesis of Cu2O@carbon nanocapsules composites using sodium alginate as template and characterization of their visible light photocatalytic properties

A One step-synthesis method was developed to fabricate composite photocatalysts from cuprous oxide and carbon nanocapsules (Cu2O/CNC), using sodium alginate as a template. Carbon nanocapsules and nanosheets were self-generated by calcination in the presence of Cu2+ species. And Cu2O particles with a diameter of 20–50 nm were distributed in the carbon nanocapsules or on the surface of the carbon nanosheets. The carbon nanomaterials provide a large surface area, which makes it easier for Cu2O to immobilize dye molecules through hydrogen bonding. Batch adsorption and degradation experiments were carried out using catalysts synthesized under different conditions, including sodium alginate fraction, crosslinker concentration, and precipitant concentration. The results showed that the Cu2O/CNC composite catalysts exhibited excellent photodegradation performance under visible light, removing 90% of methyl red in 120 min. The removal efficiency and photodegradation rate were affected significantly by a) the specific area of the catalysts; b) the morphologies of Cu2O and carbon nanomaterials; c) the synergy between Cu2O and carbon nanomaterials. A detailed mechanism for the enhancement of photocatalytic activity towards degradation of methyl red is proposed.

Preparation and characterization of 2D ZnO nanosheets/regenerated cellulose photocatalytic composite thin films by a two-step synthesis method

2D ZnO nanosheets-regenerated cellulose (ZNSRC) photocatalytic composite thin films were prepared from ZnCl2 by using a two–step synthesis method at room temperature. The results show that during the formation of ZNSRC composite thin film, ZnCl2 first reacted with NaOH to form Zn5(OH)8Cl2·H2O which was then converted to ZnO. The 2D ZnO nanosheets are 350–450 nm in transverse size and 80 nm in thickness, dispersed on both the surface and inside of the ZNSRC thin films. The ZNSRC prepared by 13 h of reaction time has a characteristic of nanoporous 2D ZnO nanosheets and exhibits the best photocatalytic activity, as 1.53 × 10−5 mol methyl orange was completely degraded in 50 min by using 1 g catalyst. Thus, we can conclude that the ZNSRC photocatalytic composite thin films can be very useful for degrading organic dye wastewater.

Oxidation-Reduction Potential Control for One Step Synthesis of Cu-Pt Core-Shell Nanoparticles

Polymer electrolyte fuel cells (PEFCs) are promising power source because of their high power generation efficiency and low environmental pollution. However, PEFCs contain precious platinum catalyst in cathode and this leads to be expensive. Thus, PEFCs have to reduce the catalyst cost to be used more widely. In order to decrease the amount of platinum in the cathode, core-shell structured nanoparticles have been tried to synthesize. Core-shell structured nanoparticles mean, for example, Pt nanoparticles whose core is displaced by copper. However, most of the synthesis methods of Cu-Pt core-shell nanoparticles require high energy and multiple processes. To cut the cost of PEFCs fundamentally, low cost synthesis method of core-shell nanoparticles needs to be developed. Therefore, in this study, one step synthesis method of Cu-Pt core-shell nanoparticles was researched under a mild condition such as aqueous solution of room temperature and atmospheric pressure. Although the mild condition can cut the process cost, there are several problems. Therefore, possibility to synthesize Cu-Pt core-shell nanoparticles on the mild condition have to be evaluated before trying one step synthesis. Carbon supported Cu nanoparticles were synthesized as the first step. In the second step, the surface of the Cu nanoparticles was displaced by platinum, then Cu-Pt core-shell nanoparticles were synthesized on the mild condition in two steps. To synthesize Cu-Pt core-shell nanoparticles in one step, oxidation-reduction potential (ORP) of metal complexes was calculated and controlled. Generally, ORP of Pt is higher than that of Cu and this leads to form Pt core Cu shell structure when Pt and Cu are reduced together. To achieve Cu core Pt shell structure, ORP calculation technique was developed and the synthesis condition which can invert the ORPs of Pt and Cu was found. Therefore, one step synthesis of Cu-Pt core-shell nanoparticles was performed on this condition and several properties of low cost PEFC cathode catalyst were measured. Detailed results will be shown in our session.

Facile in-situ single step chemical synthesis of reduced graphene oxide-copper oxide-polyaniline nanocomposite and its electrochemical performance for supercapacitor application

Reduced graphene oxide (rGO)-copper oxide-polyaniline nanocomposites were synthesized by facile in-situ single step synthesis method with different weight ratio of polyaniline at fixed weight ratios of copper oxide and reduced graphene oxide (rGO); and characterized by IR spectroscopy, powder XRD, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical performances of as synthesized composites were studied using two electrode system in 2M Na2SO4 as electrolyte by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The composite with a weight of 300mg of Polyaniline (PANI), corresponding to the composition (wt %) of rGO6.6%: Cu2O/CuO13.40%: PANI80% (GCP-300) exhibited superior electrochemical characteristics with specific capacitance of 213.20Fg−1, energy density of 18.95Whkg−1, power density of 545.79Wkg−1, columbic efficiency of 91% and rendered 97.6% of retention of its initial capacitance up to 5000 charge-discharge cycles. The performance is superior to those of binary combinations of constituent materials viz., reduced graphene oxide (rGO), copper oxide and polyaniline, which is attributed to the extent of integration of afore mentioned materials.