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Under atmospheric pressure, 4-(arylamino)methyl substituted ethylene carbonates were synthesized from the reaction of carbon dioxides (1 or 0.5 atm) with aromatic amine and 2-(bromomethyl)oxirane catalyzed by a ternary system of ZnBr 2 /K 2 CO 3 /[Bmim]Br, while [Bmim]Br (1-butyl-3-methyl-1H-imidazol-3-ium bromide) acted as both catalyst and solvent in the reaction. In the catalytic protocol, the products were isolated in good to excellent yields with good selectivity (up to 96%, total 15 examples). Various functional groups, such as -OMe, -F, -Cl, -Br, -I, -Me, -Et, -COMe and -CN were found tolerant in the reaction. The presence of a small amount of water and air in CO 2 does not affect the catalytic activity, and the catalyst can be recycled. [ABSTRACT FROM AUTHOR]

A simple, readily available and recyclable ternary catalytic system of ZnBr 2 /K 2 CO 3 /[Bmim]Br was developed for the efficient conversion of CO 2 and epoxides (both internal and terminal epoxides) to cyclic carbonates under very mild conditions (room temperature, 1 atm) with excellent yields (>90% for 18 examples). The catalytic activity would not be affected by CO 2 in the presence of small amount of water and air. The reactions would even be carried out under CO 2 partial pressure as low as 0.5 atm, giving carbonate in good yield. This process has been repeated 5 times without any obvious decrease in catalytic activity. The influences of the type of catalyst, catalyst loading, CO 2 pressure, reaction time, and temperature on the reaction yields have been investigated. The possible reaction mechanism was proposed based on the reaction results. [ABSTRACT FROM AUTHOR]

The self-assemble propensity of the controlled shape and size distribution titania nanoparticles makes the particles oriented organization to ordered structures without substrate by a hydrolysis-hydrothermal route. The procedure offers the possibility of a generalized approach to the production of patterned organization of single and complex oxide nanoparticles with size and morphology tunable. [Copyright &y& Elsevier]

La1−xSrxMnO3 (x=0.3) (LSM) nanoparticles were prepared by a sonication-assisted coprecipitation method. The coprecipitation reaction is carried out with ultrasound radiation. Lower sintering temperatures are required for the sonication-assisted product. Fully crystallized LSM with an average particle size 24 nm is obtained after the as-prepared mixture is annealed at 900 °C for 2 h. Magnetic properties indicate that the transition temperature from the paramagnetic to ferromagnetic state of the sample is quite sharp and occurs at 366 K for samples annealed for 2 h at 900 and 1100 °C. [Copyright &y& Elsevier]

Abstract: Mg-doped LaCoO3 particles were prepared in various particle sizes via a modified sol–gel method using excess MgO as pinning particles. The adsorbed oxygen species of the products were studied by XPS, TPD-O2 and TPR-H2. The amount of adsorbed oxygen varied with changes in average particle size and had an important effect on the catalytic activity towards CO oxidation. XPS and TPD-O2 results indicated that there were two kinds of surface oxygen species and that the relative ratio of the surface adsorbed oxygen to lattice oxygen increased with an increasing BET surface area. The catalytic activities of Mg-doped LaCoO3 particles were clearly enhanced with the increase of surface area and the amount of adsorbed oxygen. [Copyright &y& Elsevier]

Nanoparticles of Al-doped SnO2 have been hydrothermally synthesized. The influences of the hydrothermal reaction time, the molar ratio of Sn/Al as well as the pH value of the solution have been studied. During the hydrothermal synthesis, the particle’s core is rich in Sn and the surface is rich in Al. The Al-rich surface prevents the particles from further growing up either in the hydrothermal condition or during the calcination at 600 °C for a short period of time. The optimal hydrothermal synthesis condition of the nanoparticles is pH 5, Sn/Al=4:1 and 12 h at 160 °C. The products have been studied by XRD, TEM and 27Al solid-state NMR. [Copyright &y& Elsevier]

To design an efficient and cost-effective electrocatalyst based on Prussian blue and its analogs are a promising choice to realize energy transformation and storage via water-splitting. Herein, a facile and practical method is developed to in-situ grow Fe–Co Prussian-blue-analog (PBA) nanocages with an open hole in each face center on Ni(OH) 2 /NF substrate to form the hierarchical cage-on-plate structure. Furthermore, the Fe–Co PBA nanocages attached to Ni(OH) 2 /NF plates are hydrogenated and nitrogenized into FeCoNi/NF and FeCoNiN/NF electrodes, respectively. As-prepared electrodes successfully retain the 3D hierarchical micro-nano structures of Fe–Co PBA@Ni(OH) 2 /NF precursor and can be used as a bifunctional water-splitting catalyst for overall water splitting. Compared to FeCoNi/NF, FeCoNiN/NF shows more efficiency and durability in the electrolytic water splitting tests in alkaline media. For the FeCoNiN/NF electrocatalyst, ultralow overpotentials for hydrogen evolution reaction (HER) are only 56 and 290 mV at current densities of 10 and 500 mA cm−2. Meanwhile, overpotentials for oxygen evolution reaction (OER) are 267 and 374 mV at current densities of 50 and 500 mA cm−2. The FeCoNiN/NF electrode can act both the cathode and the anode for overall water splitting, this electrolyzer only requires a cell voltage of 1.492 V to afford a current density of 10 mA cm−2. This electrolyzer can stably deliver a viable high current density of 625 mA cm−2 for 40 h to meet the condition of industrial application. Schematic illustration for the formation of a hierarchical structural electrode. Image 1 • PBA nanocages are fabricated on Ni(OH) 2 /NF to form a cage-on-sheet structure. • The derivatives, FeCoNi/NF and FeCoNiN/NF, are bifunctional electrocatalysts. • FeCoNiN/NF shows excellent performance in the electrolytic water splitting tests. [ABSTRACT FROM AUTHOR]

To investigate the influence of annealing temperature on the structure and photoluminescence property, 5% wt. Eu3+ doped MgAl 2 O 4 ceramics have been synthesized by a solution combustion reaction and thermally treated at 700, 800, 900, 1000, 1100, and 1200 °C. Powder XRD indicate that pure spinels were synthesized and the crystallinity increased with the increase of the heat treatment temperature. Low temperature heat capacities of these phosphors were measured and the data were fitted by T3 Debye model. The obtained Debye temperature of sample show positive relationship with the calcine temperature. Our results suggest that the heat treatment improves the crystallinity and decreases the structure defects of MgAl 2 O 4 :Eu3+. The SEM shows spongy structure of the particles is dependent on the calcine temperature. These phosphors exhibit hypersensitive red emission peaking at 613 nm, which corresponds to the electric-dipole 5D 0 - 7F 2 transition of Eu3+ ions. Comparison between the excitation and emission spectra has shown modification of their spectroscopic characteristics. The MgAl 2 O 4 :Eu3+ calcined at 900 °C shows the best performance based on the dominant red (5D0-7 F2) emission and the effective emission excited by near-UV 394 nm show potential applications in solid state lighting. [ABSTRACT FROM AUTHOR]

Carbon disulfide is an abundant, inexpensive and readily available material. One of the main challenges in the reaction of epoxides with CS 2 is to control the chemoselectivity as a variety of compounds would be formed in the reaction. A simple and convenient method toward selectively synthesis of oxathiolane and trithiocarbonate from epoxides with CS 2 catalyzed by NHC/LiCl(Br) under the neat conditions has been developed. This catalytic system exhibits excellent activity and selectivity in cycloaddition reactions of carbon disulfide to terminal epoxides. [ABSTRACT FROM AUTHOR]

Fe 2+ and Ti 3+ co-doped anatase TiO 2 nanocrystallites with ca. 50% exposed {001} facets have been successfully synthesized by a facile hydrothermal method. The transition metal dopant induces the stability of Ti 3+ ions in the structure. As-prepared anatase TiO 2 exhibits a broad absorbance in the visible light region, which shows blue colour. Furthermore, these Ti 3+ ions can in situ reduce the noble metal cations to neutral atoms, which form homogeneously nanoclusters on the TiO 2 surface. The noble metal anchored samples show enhanced photocatalysis compared to the original Fe,Co-doped TiO 2 sample under ultraviolet light. Among the noble metal anchored samples, Pd@Fe3–TiO 2 can completely oxidize CO at the mild temperature above 250 °C. [ABSTRACT FROM AUTHOR]

An effective intramolecular C–H arylation reaction catalyzed by a bimetallic catalytic system Pd(OAc) 2 /CuI for the synthesis of fluorine-substituted carbazoles from corresponding N -phenyl-2-haloaniline derivatives under ligand free conditions is demonstrated. The established method is effective for both N -phenyl-2-bromoaniline and N -phenyl-2-chloroaniline, and requires the low loading of Pd(OAc) 2 (0.5 mol %). A series of new fluorinated carbazoles were synthesized in excellent yields using the protocol (>83%, 19 examples) and were fully characterized by 1 H, 13 C and 19 F NMR spectral data, HRMS and elemental analysis. All compounds were evaluated for their antibacterial activities against four bacteria ( Bacillus subtilis , Staphylococcus aureus , Escherichia coli and methicillin-resistant S. aureus with resistance to gentamicin) by serial dilution technique. All tested compounds showed antibacterial activity against three test strains ( S. aureus , B. subtilis and MRSA), and most of these compounds displayed pronounced antimicrobial activities against these three strains with low MIC values ranging from 0.39 to 6.25 μg/mL. Among them, compounds 7 and 14 exhibited potent inhibitory activity better than reference drugs meropenem and streptomycin. Three compounds ( 2 , 4 and 5 ) showed antibacterial activity against E. coli . with MIC values from 12.5 to 25 μg/mL. [ABSTRACT FROM AUTHOR]

Abstract: The phosphine-free mono- and double-Heck reaction of terminal olefins with electron-deficient and electron-rich aryl halides (iodides and bromides) is described. These reactions are catalyzed by the dicarbene dipalladium complex 1 by controlling the stoichiometry of the aryl halide and the olefine, the loading of the palladium catalyst, as well as using different base, and with or without additive. The procedure of double-Heck reaction allows β,β-diarylation and β,β′-diarylation of terminal olefins and affords trisubstituted olefins in good to excellent yields. [Copyright &y& Elsevier]

Abstract: It was found that an air-stable NHC–palladium complex of Pd[(s)-3-C3H5-4-(C5H5CH2)-1-(2,6- i Pr2C6H3)-C3H3N2](C5H5N)Br2 derived from l-phenylalanine is an effective pre-catalyst for copper-free and phosphine-free Sonogashira reaction of alkynes under aerobic conditions in short reaction time. Moreover, the palladium compound would be reused to catalyze the hydroarylation of alkyne prepared from Sonogashira reaction, which makes firstly Sonogashira/Hydroarylation sequential reactions successful. The arylation of alkynes underwent with a high regio- and stereoselectivity and only trans-arylation of alkyne was observed. No Z/E isomerization of the olefin was observed in the system. [Copyright &y& Elsevier]

Nd 1.93 Sr 0.07 CuO 4 nanofibers are prepared by electrospinning technique followed by a simple thermal treatment. The morphology and phase evolution of as-obtained fibers are characterized by TG-DTA, XRD, FT-IR and SEM, respectively. Typical ceramic fiber diameter is 100–200 nm, with length exceeding tens of microns. Rapid heating the nanofiber cathode at 1000 °C for 15 min results in homogeneous porous microstructure and good contact with the CGO electrolyte. EIS analysis of the nanofiber electrode gives a polarization resistance of 0.26 Ω cm 2 at 700 °C in air, two times smaller than that from the powder cathode with the same composition. The excellent electrochemical performance can be attributed to the well constructed microstructure of the fiber cathode, which can promote surface oxygen diffusion or adsorption processes on the cathode. [ABSTRACT FROM AUTHOR]

Abstract: Nd1.93Sr0.07CuO4 nanofibers are prepared by electrospinning technique followed by a simple thermal treatment. The morphology and phase evolution of as-obtained fibers are characterized by TG-DTA, XRD, FT-IR and SEM, respectively. Typical ceramic fiber diameter is 100–200 nm, with length exceeding tens of microns. Rapid heating the nanofiber cathode at 1000 °C for 15 min results in homogeneous porous microstructure and good contact with the CGO electrolyte. EIS analysis of the nanofiber electrode gives a polarization resistance of 0.26 Ω cm2 at 700 °C in air, two times smaller than that from the powder cathode with the same composition. The excellent electrochemical performance can be attributed to the well constructed microstructure of the fiber cathode, which can promote surface oxygen diffusion or adsorption processes on the cathode. [Copyright &y& Elsevier]

Two different nanosized materials were synthesized by two preparation methods, namely a sonochemical technique and a spray pyrolysis process. The powder properties, the sintering behavior and the resulting crystallinity with respect to their utilisation for solid oxide fuel cell electrolytes were investigated. While the spray pyrolysis provides crystallized powder without any organic residue, the sonochemical powder is amorphous with some organic residue. Crystallization begins in the 400–500 °C temperature domain. The particle sizes vary between 10 and 50 nm for the sonochemical powder and between 50 nm and 1 μm for the spray pyrolysis powder, as determined by SEM analyses. Crystal growth of both powders starts between 800 and 1000 °C. After heating and sintering at 1300 °C the resulting grain sizes of the spray pyrolysis powder are 5 times larger than those of the sonochemical powder (about 250 nm and 1.2 μm, respectively). Additionally, the maximum rate of grain growth for the spray-pyrolysed material at 97 nm/h is even higher compared with 22 nm/h for the sonochemical powder. [Copyright &y& Elsevier]

Abstract: CoNb2O6 was prepared by hydrothermal synthesis with polyvinyl alcohol as an additive. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to investigate the lattice parameters and the particle morphology. The products were observed as irregular particles with an average particle size of ca. 500nm, which agglomerated from thin slices. Compared with the common columbite CoNb2O6, which was obtained by a traditional solid-state reaction, the product obtained by the hydrothermal method crystallized into a rutile structure. The rutile CoNb2O6 was metastable and it could transform into the columbite structure after calcining at 800°C in air for 4h. [Copyright &y& Elsevier]

Abstract: α-Fe2O3 nanoparticles/TiO2 nanowires hybrid structure is fabricated by two-step hydrothermal treatment. TiO2 nanowires are prepared by heating of titanate nanowires, which are obtained by hydrothermal treatment of TiO2 powder and further repeated HCl treatment. α-Fe2O3 nanoparticles are deposited on the surface of TiO2 nanowires by hydrothermal treatment in Fe(NO3)3 solution. The HRTEM images confirm the junctions between α-Fe2O3 nanoparticles and TiO2 nanowires. The formation of hybrid structures has significant influence on the magnetic properties of α-Fe2O3. The Morin transition temperature of α-Fe2O3 nanoparticles/TiO2 nanowires hybrid structure is 190K, which is determined by the sharp peak in the differential ZFC curve. Whereas there is no observable Morin transition for the corresponding isolated α-Fe2O3 nanoparticles with similar average particles size of ca. 20nm. [Copyright &y& Elsevier]