Separation and purification of polyprenols from Ginkgo biloba leaves by silver ion anchored on imidazole-based ionic liquid functionalized mesoporous MCM-41 sorbent.

Polyprenols (PPs) are compounds with excellent biological activities and are applied in food, pharmaceutical, and cosmetic industries. However, its strong non-polar nature makes it difficult to separate with many saturated impurities (such as saturated fatty acids) extracted together. Complexation extraction is an effective method for separating saturated and polyunsaturated compounds.

Altering Ligand Microenvironment of Atomically Dispersed CrN by Axial Ligand Sulfur for Enhanced Oxygen Reduction Reaction in Alkaline and Acidic Medium.

Because of the instability and Fenton reactivity of non-precious metal nitrogen-carbon based catalyst when processing the oxygen reduction reaction (ORR), seeking for electrocatalysts with highly efficient performance becomes very highly desired to speed up the commercialization of fuel cell. Herein, chromium (Cr)-N  electrocatalyst containing extraterrestrial S formed axial S -Cr N  bonds (S Cr N C) is achieved via an assembly polymerization and confined pyrolysis strategy. Benefiting from the adjusting  coordination configuration and electronic structure of the metal center through axial coordination, S Cr N C exhibits enhanced the intrinsic activity (half-wave potential (E ) is 0.

Preparation of Expanded Graphite and Graphite Nanosheets for Improving Electrical Conductivity of Polyester Coating Films.

Expanded graphite and graphite nanosheets were facilely prepared by the thermal expansion of expandable graphite at 800 °C and sand milling of expanded graphite in water, respectively. When the expandable graphite precursor was prepared by the oxidation and intercalation of natural graphite (5 g) using KMnO₄ (6 g) as an oxidant in a concentrated sulfuric acid solution (120 mL) at room temperature (25 °C) for 8 h, the expanded graphite with a maximum volumetric rate of 317 mL g was prepared after the thermal expansion of the expandable graphite precursor at 800 °C for 60 s. The oxidation extent of natural graphite with KMnO₄ is crucial for the preparation of expanded graphite.

Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity.

As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O reduction preferentially takes place on Fe in the FeN /C system with intermediate spin state which possesses one e electron (t4e1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the Fe sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.

Preparation of Hollow SiO₂@BiOI Nanocomposites and Their Photocatalytic Performance in Ammonia Nitrogen Degradation.

Hollow SiO₂ microsphere-supported bismuth oxyiodide (BiOI) nanocomposites were prepared using Bi(NO₃)₃ · 5H₂O and KI as the precursors of BiOI at 80 °C in an aqueous solution by the liquid chemical deposition method. The BiOI nanosheets with the thicknesses of 25-40 nm and the widths of 1-2 m were deposited on the hollow SiO₂ microsphere surfaces. There were interactions between the BiOI nanosheets and hollow SiO₂ microspheres, which enlarged the ban gap of the BiOI nanosheet as compared with the pure BiOI.

Oxidation of 1,2-Propanediol to Carboxylic Acid Over Hydroxyapatite Nanorod-Supported Metallic Cu Nanoparticles.

Hydroxyapatite nanorod-supported metallic Cu nanoparticle catalysts (Cu/HAP) were prepared by the wetness chemical reduction method. The metallic Cu nanoparticles were well dispersed on the surfaces of the HAP nanorods. The alkaline HAP nanorods inhibited the crystal growth of the metallic Cu0 nanoparticles.

Preparation of Different-Sized Copper Nanoparticles by Reducing Copper Hydroxide and Application in Lithium-Based Grease.

Copper nanoparticles with different average particle sizes of 61-139 nm were facilely prepared by the wet chemical reduction of copper hydroxide without or with the use of organic modifier. Sodium dodecyl benzene sulfonate as an organic modifier effectively decreased the sizes of copper nanoparticles as compared to sodium citrate. The presence of polyvinylpyrrolidone favored the formation of the small-sized copper nanoparticle.

Functional characterization of bimetallic CuPd nanoparticles in hydrothermal conversion of glycerol to lactic acid.

The crude glycerol from biomass represents an abundant and inexpensive resource which can be utilized in producing food additives such as lactic acid. The direct transformation of bioderived glycerol to lactic acid under the catalysis of bimetallic CuPd nanoparticles as well as monometallic Cu and Pd was investigated in hydrothermal conditions. The properties of fresh and spent bimetallic CuPd nanoparticles were characterized with various physicochemical techniques viz.

Morphology-controlled synthesis of calcium titanate particles and adsorption kinetics, isotherms, and thermodynamics of Cd(II), Pb(II), and Cu(II) cations.

CaTiO particles with different particle sizes and morphologies were synthesized starting from CaCl and titanium (IV) isopropoxide with or without the use of organic modifier by the hydrothermal synthesis method. Without the use of organic modifier, nanosized CaTiO particulates were mainly formed at the hydrothermal temperatures of 120 C and 140 C whereas CaTiO cuboids were predominantly formed at 180 C. The utility of polyethylene glycol as an organic modifier favored the formation of small-sized CaTiO nanoparticulates.

Hydrogenation of 1-Nitroanthraquinone to 1-Aminoanthraquinone Catalyzed by Bimetallic CuPt Nanoparticles.

Bimetallic CuPt nanoparticles were prepared in ethanol solution by the wet chemical reduction method using Cu(NO₃)₂ and H₂PtCl as starting materials, hydrazine hydrate as a reductant, and polyvinyl pyrrolidone as an organic modifier. The average particle sizes of Cu and Pt nanoparticles were 60 nm and 3 nm, respectively. The small-sized Pt nanoparticles were evenly anchored at the surfaces of large-sized Cu nanoparticles, forming Cu@Pt core-shell structured nanocomposites.

Improvement of the Tribological Properties of a Lithium-Based Grease by Addition of Graphene.

Graphene with layer number less than seven, prepared by a mechanical exfoliation method, was used as a friction-reducing additive to a lithium-based grease. The graphene was characterized via AFM, TEM, and Raman spectroscopy. The as-prepared graphene had few defects according to the characterization analysis and appeared to be composed primarily of sheets averaging 1-4 atomic layers.

Direct reaction between silicon and methanol over Cu-based catalysts: investigation of active species and regeneration of CuCl catalyst.

When a CuCl/Si mixture was pretreated at 200-240 °C in a N atmosphere, trimethoxysilane was predominantly formed in the direct reaction of silicon with methanol. When the pretreatment temperatures were raised to 260-340 °C, tetramethoxysilane was favorably formed. The Cu Si Cl species catalyzed the reaction between silicon and methanol to trimethoxysilane.

Bioinspired Synthesis of Au Nanostructures Templated from Amyloid β Peptide Assembly with Enhanced Catalytic Activity.

Peptides have been regarded as useful biomolecule templates to control the synthesis of various inorganic nanomaterials in mild conditions. Inspired by this, the easily self-assembled amyloid β (Aβ) peptide was developed as an alternative template to prepare Au nanostructures for the enhanced catalytic activity, for instance, the reduction of 4-nitrophenol. The presence of Aβ peptide assemblies with different structures could direct the nucleation of Au to form different Au nanostructures.

Adsorption Kinetics, Isotherms, and Thermodynamics of Cr(III), Pb(II), and Cu(II) on Porous Hydroxyapatite Nanoparticles.

Porous hydroxyapatite (HAP) nanoparticles with the specific surface area of 76.1 m2 g-1 were facilely prepared using calcium nitrate and phosphoric acid as the starting materials and ammonia aqueous solution as the pH regulator by a hybrid precipitation and hydrothermal method at lower reaction temperatures of 35 and 110 °C. The adsorption of Cr(III), Pb(II), and Cu(II) ions on HAP nanoparticles was well simulated by the pseudo-second-order adsorption kinetics and Langmuir adsorption isotherm.

Selective Oxidation of 1,2-Propanediol to Carboxylic Acids Catalyzed by Copper Nanoparticles.

Copper nanoparticles with different particle sizes were prepared by a wet chemical reduction method in the presence of organic modifiers, such as citric acid (CA), hexadecyl trimethyl ammonium bromide, Tween-80 (Tween), and polyethylene glycol 6000. Selective oxidation of sustainable 1,2-propanediol with O2 to high-valued lactic, formic, and acetic acids catalyzed by the copper nanoparticles in an alkaline medium was investigated. The small-sized CuCA nanoparticles with the average particle size of 15.

Catalytic Conversion of Glycerol to Lactic Acid Over Hydroxyapatite-Supported Metallic Ni Nanoparticles.

Catalytic conversion of low-priced biomass glycerol to value-added lactic acid is an alternative route to the conventional fermentation process using sugar as the starting material. Nanosized hydroxyapatite-supported metallic Ni0 nanoparticles (Nix/HAP) prepared by the wetness chemical reduction method effectively catalyzed the conversion of high-concentrated glycerol (1.5-3 mol L-1) to lactic acid in a NaOH aqueous solution.

Catalytic Conversion of Glycerol to Lactic Acid Over Metallic Copper Nanoparticles and Reaction Kinetics.

Different-sized metallic Cu⁰ nanoparticles were prepared by the wet chemical reduction method with organic modifiers. The small-sized Cu⁰ nanoparticles (Cu(PEG)) prepared by using polyethylene glycol as the organic modifier exhibited high catalytic activity for the hydrothermal conversion of glycerol to lactic acid. When the reaction was carried out with the initial glycerol and NaOH concentrations of 1.

Conversion of Glycerol to Lactic Acid Catalyzed by Different-Sized Cu₂O Nanoparticles in NaOH Aqueous Solution.

Different-sized Cu₂O nanoparticles with the average particle sizes ranging from 115 to 423 nm were prepared starting from CuSO₄ using ascorbic acid as the reductant at room temperature. When Cu₂O nanoparticles were used as the catalysts for hydrothermal conversion of glycerol at 230 °C in a NaOH aqueous solution, Cu₂O nanoparticles effectively catalyzed the hydrothermal conversion of glycerol to lactic acid as compared to the conventional hydrothermal conversion of glycerol in a “pure” NaOH aqueous solution. Small-sized Cu₂O nanoparticles showed higher catalytic activity than the large-sized ones.

Fluoride Release from Hollow Silica Microsphere-Containing Dental Restorative Acrylate Resin.

Hollow silica microspheres with mesoporous shells were prepared by the sacrificial template method. Hollow silica microsphere-containing acrylate resin-based dental restoration materials were prepared by using hollow silica microspheres as NaF reservoirs. Fluoride release performances from naked hollow silica microspheres, acrylate resin, and hollow silica microsphere-containing acrylate resin-based dental restorative materials in an artificial saliva were investigated.

Selective Chlorination of Toluene to p-Chlorotoluene Catalyzed by Nanosized Zeolite K-L Catalysts.

Nanosized zeolite K-L catalysts were synthesized by the hydrothermal method starting from silica sol and potassium aluminate. The crystallinities of the zeolite K-L catalysts increased with increasing the SiO2/Al2O3 mole ratio of reaction solution and prolonging the autoclaving time. Nanosized and well-dispersed zeolite K-L catalysts were synthesized when the SiO2/Al2O3 mole ratio was more than 26:1.

Synthesis of different sized and porous hydroxyapatite nanorods without organic modifiers and their 5-fluorouracil release performance.

Porous biocompatible hydroxyapatite (HAP) nanorods of various sizes were synthesized by the combination of chemical precipitation and hydrothermal method without the use of organic modifiers. The HAP nanorod samples were characterized by powder X-ray diffraction, transmission electron microscopy, and N2 adsorption/desorption techniques. HAP nanorods with average diameters and average lengths ranging from 8.

Fabrication of a novel graphene oxide/β-FeOOH composite and its adsorption behavior for copper ions from aqueous solution.

A graphene oxide (GO)/β-FeOOH composite was prepared by the liquid insert method and was characterized by XRD, FT-IR, SEM and TEM. The adsorption capacity of the composite was evaluated by the removal of copper ions (Cu(2+)) from aqueous solution. The effect of initial pH, contact time and absorbent dose on the removal efficiency of Cu(2+) was investigated by batch experiments.

Preparation of hollow titania spheres and their photocatalytic activity under visible light.

Hollow titania spheres with different shell thicknesses were facilely prepared starting from TiCl4 and using ploystyrene methyl acrylic acid latexes as the sacrificial templates. The average diameters of the hollow titania spheres ranging from 294 to 340 nm were tuned by changing the weight ratios of TiO2 to ploystyrene methyl acrylic acid latex from 0.8:1 to 1.

Synthesis and characterization of LiFePO4/C cathode materials by sol-gel method.

The carbon coated LiFePO4 cathode materials (LiFePO4/C) were successfully synthesized by sol-gel method with glucose, citric acid and PEG-4000 as dispersant and carbon source, respectively. The microstructure and grain size of LiFePO4/C composite were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy. The results showed that the carbon source and calcination temperature had important effect on the graphitization degree of carbon; the carbon decomposed by citric acid had higher graphitization degree; with calcination temperature rising, the graphitization degree of carbon increased and the particles size increased.

Effect of carbon source on the morphology and electrochemical performances of LiFePO4/C nanocomposites.

The carbon coated LiFePO4 (LiFePO4/C) nanocomposites materials were successfully synthesized by sol-gel method. The microstructure and morphology of LiFePO4/C nanocomposites were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The results showed that the carbon layers decomposed by different dispersant and carbon source had different graphitization degree, and the sugar could decompose to form more graphite-like structure carbon.