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BiVO nanoparticles are prepared by molten salt method. Tetragonal BiVO completely transforms to monoclinic phase after heating in molten LiNO at 270 °C for 18 h. The average particle sizes of monoclinic BiVO varied from 30 to 52 nm while the initial ratio of BiVO to LiNO changes from 1:6 to 1:24. The photocatalytic activity is evaluated by measuring decolorization of N, N, N′, N′-tetraethylated rhodamine dye solution under visible-light irradiation. Both of the de-ethylation and chromophore cleavage are responsible for the decolorization of RB. The sample with an average particle size of 52 nm and a moderate surface area of 10 m/g exhibit the highest visible-light photocatalytic activity. The shift of Raman peak position indicates that the symmetry distortions in the local structure of the monoclinic BiVO. The variations of the local structure result in the modification of the electronic structure, which is responsible for the high visible-light photocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: Fe3+–Nb5+ co-doped SnO2 was prepared at 1200°C by a simple chemical co-precipitation method. The Sn1−2 x Fe x Nb x O2 solid solutions kept cassiterite structure in the range of 0

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]

A selective extraction process for recovering vanadium (IV) over chromium was proposed with use of a mixed extractant consisting of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP). The influence of various factors, which included the initial aqueous pH value, the concentration of leach solution and D2EHPA, phase ratio (O/A), extraction equilibrium time and extraction temperature in the extraction process on the separation of V and Cr was investigated. Under the condition of the optimum extraction, vanadium extraction was above 94.0%. Meanwhile, under the optimum stripping conditions, the vanadium stripping was above 93.0% utilizing 1.5 mol/L sulfuric acid as the effective stripping reagent. The regeneration and reusability of the loaded organic phases after stripping were discussed. In addition, continuous three-stage extraction and stripping strategy indicated that the aggregate loss of vanadium was 0.885% and that the purity of vanadium was more than 99.9%. Under the condition of the optimum precipitation, when the pH value of the stripping solution was adjusted to 7.0 with ammonia water, the precipitation efficiency reached 99.93%. The calcination conditions (above 680 °C in air) were finally determined by TG-DTA and TG-MS experiments, and the V2O5 obtained by calcination was characterized by XRD. Additionally, a method for detecting impurity elements in vanadium matrix without interference was established. The recovery technology has practical significance in enlarging production scale, reducing specific energy consumption and cost, and realizing automatic control in vanadium leaching process. [ABSTRACT FROM AUTHOR]

The design of graphene quantum dots (GQDs)-aptamer bioconjugates as the new sensing platform is very important for developing high-sensitivity fluorescent biosensors; however, achieving new bioconjugates is still a great challenge. Herein, we report the development of a new high-sensitivity fluorescent aptasensor for the detection of ochratoxin A (OTA) based on tuning aggregation/disaggregation behavior of GQDs by structure-switching aptamers. The fluorescence sensing process for OTA detection involved two key steps: (1) cDNA-aptamer (cDNA, complementary to part of the OTA aptamer) hybridization induced the aggregation of GQD (fluorescence quenching) after cDNA was added into the GQDs-aptamer bioconjugate solution, and (2) the target of OTA triggered disaggregation of GQD aggregates (fluorescence recovery). Such new fluorescent sensing platform can be used to monitor OTA with a linear range of 0 to 1 ng/mL and very low detection limit of 13 pg/mL, which is among the best in all the developed fluorescent nanoparticles-based sensors. Such sensing strategy is also successful in analyzing OTA in practical red wine sample with 94.4-102.7% of recoveries and relative standard deviation in the range of 2.9-5.8%. The present works open a new way for signaling the target-aptamer binding event by tuning aggregation/disaggregation behavior of GQDs-bioconjugates. [ABSTRACT FROM AUTHOR]

A novel Fenton reagent, chalcopyrite CuFeS nanocrystals (NCs) with an average diameter of 10.6 ± 1 nm are synthesized by a facile solution phase method in a standard Schlenk Line, and they can efficiently degrade organic dyes (methylene blue, rhodamine B and rhodamine 6G) aqueous solution (100 mg L) within 1 min. XRD and TEM have been carried out to determine the crystal information, size, and shape of CuFeS NCs. The degradation process is investigated by UV-Vis spectroscopy, and its advantage is illustrated by comparing with bulk chalcopyrite. X-ray photoelectron spectroscopy is used to discuss its degradation mechanism. Based on this Fenton reagent, CuFeS NCs/biomass composite degradation column is made using sawdust as substrate, and it can efficiently degrade organic dyes continually (the total amount of organic dyes degraded by the column are 8.67, 8.44, and 8.64 times the amount degraded by pure CuFeS NCs, respectively). [ABSTRACT FROM AUTHOR]

Protein phosphorylation regulates and controls protein activity and function, which is the most basic and important part in organisms' lives. However, the low abundance and ionization inhibition of phosphopeptides make it difficult to understand and analyze the protein phosphorylation mechanism. In this study, we synthesize a core‐shell structured magnetic Ti4+‐based immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides. The introduction of negatively charged carbon layer increases the specific surface area and avoids loss of the immobilized Ti4+ during sample loading and washing. The synthesized magnetic superhydrophilic extractant is employed to separate and enrich phosphopeptides from standard protein digests coupled with MALDI‐TOF MS. It exhibits excellent enrichment performance of high selectivity (1 : 2000 molar ratio of β‐casein and BSA), sensitivity (low detection limit of 4 fmol) and preferable reusability (at least 12 times) as well as excellent adsorption capacity of 142.5 mg ⋅ g−1 and high recovery rate of 85.6 %. Moreover, sixteen phosphopeptides and four endogenous phosphopeptides can be accurately identified from non‐fat milk and human serum, further indicating the great potential and bright application in phosphoproteomics analysis. [ABSTRACT FROM AUTHOR]

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]

In this work, ZnO microrods with etched surface are prepared by two-step hydrothermal reaction. ZnO microrods are prepared firstly by decomposing LHS-Zn under hydrothermal conditions. It is found that the (0001)-Zn face of ZnO microrods will dissolve partly due to the existence of LHS-Zn during further hydrothermal treatment, and ZnO microrods with etched surface are obtained. X-ray powder diffraction is used to determine the crystal structure, and scanning electron microscopy is used to observe the morphology of products. The photoluminescence spectra are investigated. [ABSTRACT FROM AUTHOR]

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]

A MOF material has been grown on metallic transition metal nitride for electrocatalytic OER. The as-prepared hierarchical NiFe-MOF@Ni3N nano/microsheet array electrocatalyst exhibits a low overpotential of 281 mV at a current density of 200 mA cm−2 with a remarkable stability of 50 h. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO2) nanoparticles were prepared sonochemically, by using cerium nitrate and azodicarbonamide as starting materials, and ethylenediamine or tetraalkylammonium hydroxide as additives. The additives have a strong effect on the particle size and particle size distribution. CeO2 nanoparticles with small particle size and narrow particle size distribution are obtained with the addition of additives; while highly agglomerated CeO2 nanoparticles are obtained in the absence of additives. Monodispersed CeO2 nanoparticles with a mean particle size of ca. 3.3 nm are obtained when tetramethylammonium hydroxide (TMAOH) is used as the additive and the molar ratio of cerium nitrate/azodicarbonamine/TMAOH is 1/1/1. Blue shifts of the absorption peak and the absorption edges of the products are observed in the UV-Vis absorption spectra as a result of the quantum size effect. The samples have been characterized using powder XRD, TEM, DLS, and absorption spectra. [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]

A stainless steel mesh supported TiO 2 nanowires membrane is prepared by heating hydrogen titanate nanowires deposited on stainless steel mesh. The stainless steel mesh supported TiO 2 nanowires membrane exhibits superhydrophilic and underwater superoleophobic property. The water contact angles in air of the stainless steel mesh supported TiO 2 nanowires membrane is 0° and the underwater oil contact angles (gasoline, n-hexadecane, hexamethylene and methylbenzene) are >150°. Both of surfactant-free oil-in-water mixtures and surfactant-stabilized emulsions are separated with a high permeation flux of >106 L m−2 h−1 bar−1 and a separation efficiency of >99.1%. The stainless steel mesh supported TiO 2 nanowires membrane exhibits good resistant to fouling, and the possible organic pollutants are easy to be removed by heat treatment and the superhydrophilic and underwater superoleophobic property is recovered. Unlabelled Image • We successfully deposit TiO 2 nanowires on the stainless steel mesh. • The prepared stainless steel mesh supported TiO 2 nanowires membrane exhibits an ultra-high flux. • The membrane exhibits superhydrophilic and underwater superoleophobic property. • Both of surfactant-free oil-in-water mixtures and surfactant-stabilized emulsions can be separated. • The possible organic pollutants on the membrane are easy to be removed by heat treatment. [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]

Hexagonal (NH4)xWO3 has emerged as a promising photothermal agent in recent years due to the charge compensation reaction when cation intercalation occurs. We chose the ammonium ion to intercalate into the hexagonal crystal channel of tungsten oxide because of its appropriate ion radius and unique interaction with the hexagonal channel. The transmission electron microscope image shows that the morphology of the as‐prepared (NH4)xWO3 is a nanorod with a 10 nm radius and 50 nm length. The product exhibits strong absorption across the whole near infrared and ultraviolet light spectrum, as well as part of the visible light spectrum. Moreover, it exhibits a photothermal conversion efficiency up to 69.3 % at 808 nm with good photothermal stability, and features excellent biocompatibility during the co‐culture process with MC3T3‐E1 cells. Ammonium was intercalated into the hexagonal crystal channel of tungsten oxide to produce hexagonal (NH4)xWO3 as nanorods with a 10 nm radius and 50 nm length. The product exhibits strong absorption across the whole near infrared and ultraviolet light spectrum, as well as part of the visible light spectrum. Moreover, it exhibits a photothermal conversion efficiency up to 69.3 % at 808 nm with good photothermal stability, and features excellent biocompatibility during the co‐culture process with MC3T3‐E1 cells. [ABSTRACT FROM AUTHOR]

The design of efficient catalysts for the selective oxidation of sp3 C–H bond with air at low temperature is of great importance to the scientific and industrial community. In this work, we design a CeO2–δ modified CuFe2O4 catalyst by a post‐modification method for the selective oxidation of fluorene under an air atmosphere and N‐hydroxyphthalimide (NHPI) at 60 °C. HRTEM results indicate that CeO2–δ nanoclusters sized around 5 nm are successfully modified on the surface of CuFe2O4. XPS and H2‐TPR results show that CeO2–δ modification would favor oxygen transfer at lower temperature due to the synergetic effect between CuFe2O4 and CeO2–δ with rich Ce3+/Ce4+ couples. The results demonstrate that CuFe2O4@CeO2–δ‐0.05 with 4.20 wt.‐% Ce present the best catalytic performance with 94 % conversion of fluorene and excellent reusability at least five times. It is anticipated that the modification of CeO2–δ nanoclusters on the surface leads to increased oxygen activation and transfer to CuFe2O4, which favors the activation of NHPI to phthalimide‐N‐oxyl (PINO) radicals and exhibits an improved catalytic performance. Our results provide some guidance on the design of efficient catalysts by the surface modification strategy. CeO2–δ modification with 4.20 wt.‐% Ce on the surface of CuFe2O4 nanoparticles favors oxygen transfer at lower temperature and leads to better catalytic activity than that of pure CuFe2O4 for the aerobic selective oxidation of fluorene due to the synergetic effect between CuFe2O4 and CeO2–δ with Ce3+/Ce4+. [ABSTRACT FROM AUTHOR]

Abstract Oleanolic acid is an antitumor traditional Chinese medicine component whose oral efficacy and clinical applications are limited because of its strong hydrophobicity. Recently, the use of metal–organic frameworks (MOFs) as drug carriers has attracted considerable research attention. In this study, the hollow structure of MOF-5 was synthesized. Its drug loading and drug release capacity were studied. The human ovarian cancer SK-OV-3 cell line was selected to study the drug loading system, cytotoxicity, and cellular uptake. We concluded that a hollow MOF with an excellent morphology was successfully fabricated in the experiment; it increased the drug loading capacity, achieved a more ideal sustained-release effect, improved the treatment efficiency of the hydrophobic Chinese medicine component, and provided a relatively efficient drug loading material. Graphical abstract Unlabelled Image Highlights • The novel hollow nanocages MOF-5 were synthesized. • Try to solve the load-bearing problem of insoluble antitumor drug oleanolic acid • The carrier entered the cytoplasm through endocytosis, the drug could be freed from the carrier to exert its efficacy. [ABSTRACT FROM AUTHOR]

Abstract: An effective three‐component fixation of atmospheric CO2 with readily available 1,2‐dichloroethane and aromatic amine toward oxazolidinones catalyzed by in situ NHC was developed. The reaction occurred in good to excellent yields with good generality and wide functional group tolerance, including challenging steric hindered substituted‐dichloroethane (e.g. 1,2‐dichloropropane and 2,3‐dichlorobutane). The catalytic system is not sensitive to air and moisture, and high yield of oxazolidinone was achieved even with about 0.3 atm of pressure of carbon dioxide. The mechanistic study suggests that the reaction catalyze by in situ NHC via NHC‐CO2 adduct, 1‐butyl‐3‐methylimidazolium‐2‐carboxylate as intermediate and aminochloride involves in reaction pathways. The catalyst can be recycled for at least 3 times without obvious loss of catalytic activity. The protocol is also effective to prepare six‐membered 3‐aryl‐1,3‐oxazinan‐2‐one and even seven‐membered 3‐aryl‐1,3‐oxazepan‐2‐one, when 1,3‐dichloropropane and 1,4‐dichlorobutane was employed. [ABSTRACT FROM AUTHOR]

It is highly desirable to develop new semiconductors for the photocatalytic reduction of CO2 to CH4 and CO to solve greenhouse effect and energy issues. Defect pyrochlore oxides have a flexible composition and the electron/hole mobility can be manipulated by introducing foreign cations into the structure. Through Sn doping into the defect pyrochlore oxide KNbWO6·H2O, we successfully obtained a 2-times higher photocatalytic activity for converting CO2 to CO, CH4 and O2 compared to the original KNbWO6·H2O. According to the data from UV-vis, photoluminescence, and hydroxyl radical amount-related fluorescence spectra, and CO2 adsorption, the improved photocatalytic activity can be attributed to the extended visible light response, the enhanced charge separation and the improved CO2 adsorption due to Sn doping. Our results provide a new strategy for developing high-performance photocatalysts. [ABSTRACT FROM AUTHOR]

A convenient and effective method of synthesizing 3-aryl-2-oxazolidinones from cyclic carbonates and aryl amines catalyzed by bio-catalyst adenine in the presence of Et3N under solvent-free conditions is described. The protocol is suitable for the wide scope of substrates, e.g. cyclic carbonates with or without substitutes, and aryl amines with either electron-withdrawing or electron-donating group. The products were obtained in good to excellent yields under the optimal conditions, even in steric hindered cases. The effect of reaction time, temperature, loading of catalyst, and amount of starting materials in the reaction were investigated, and the reaction mechanism is discussed. [ABSTRACT FROM AUTHOR]

The cobalt carbonate hydroxide one-dimensional (1D) needle-like nanostructure is grown on the non-woven fabric via hydrothermal method. The 1D interlaced needle-like structure not only reduces the pore size of the non-woven fabric but also provides rough micro-nano structure of the superhydrophilic cobalt carbonate hydroxide/non-woven fabric, which is endowed with superhydrophobicity by coating with polydimethylsiloxane (PDMS). The resulting superwetting non-woven fabrics exhibit high separation efficiency for a series of surfactant-stabilized organic solvent/water emulsions (more than 99.3% for both W/O and O/W emulsions) and preferable recyclability (more than 10 cycles). The fluxes for all W/O and O/W emulsions are above 300 L m−2 h−1. Meanwhile the superhydrophobic fabric exhibits outstanding chemical stability in acid, alkaline and salt solution, and good mechanical durability after abrasion test with sandpaper. The comprehensive performances of the superwetting fabrics based on 1D nanostructure make them possible to be promising material for the separation of organic solvent/water mixtures in polluted water in harsh environments. [Display omitted] • The superwetting non-woven fabrics are fabricated by grafting one-dimensional (1D) needle-like nanostructure. • The 1D structure reduces the pore size of the non-woven fabric and provides rough micro-nano structure. • The resulting fabrics exhibit high separation efficiency and favorable reusability for surfactant-stabilized emulsions. • The superhydrophobic fabric possesses outstanding chemical stability and good mechanical durability. [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]

W18O49 with a tunable oxidation state was prepared by addition of NaNO3 or NaBH4 as a redox agent in the solvothermal system. The addition of redox agents has no influence on the crystallization of W18O49. The obtained W18O49 structures keep their morphology as a bundle of nanowires with a regular hexagonal on the cross-section. W18O49 exhibits strong valence-dependent absorption features in the near-IR region. Reduced W18O49 with more W5+ has a higher concentration of oxygen vacancies, which enhances the localized surface plasmon resonance effect. Reduced W18O49 exhibits a high photothermal conversion efficiency of 59.6 % and has good photothermal stability. [ABSTRACT FROM AUTHOR]

The di-N-heterocyclic carbene (NHC) dipalladium complexes, [(PdPyBr2)2(di-NHCimi)] and [(PdPyBr2)2(di-NHCtri)], di-NHCimi and di-NHCtrirepresent an imidazolylidene and a triazolylidene, respectively, featuring a 1,4-xylylene spacer between the carbene units, have been prepared. The influences of the imidazolylidene and triazolidene backbone and different substituents on the catalytic activity have been investigated in the Mizoroki-Heck reaction of styrene with bromobenzene. [ABSTRACT FROM AUTHOR]

An extremely stable Tb coordination polymer, TbL2 [HL = 4-(pyrimidin-5-yl)benzoic acid], was synthesized. It exhibits high thermal and chemical stability. TbL2 is a visual multiresponsive luminescent probe that can selectively detect F- among the same main-group anions as well as various pollutant phosphorus anions. [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]

[Display omitted] • An underliquid dual superlyophobic membrane with hierarchical micro/nanostructure is constructed. • The underliquid dual lyophobicity of polyethersulfone nanoparticles and the microporous structure formed by Zn-Ni-Co LDH nanowires synergistically contribute to the underliquid dual superlyophobic performance. • The underliquid dual superlyophobic membrane is beneficial for the separation of organic liquid/water emulsions. • The proposed strategy is effective for preparing underliquid dual superlyophobic membranes with various supporters. A hierarchical micro/nanostructure has been successfully fabricated, which is constructed by anchoring polyethersulfone (PES) nanoparticles on Zn-Ni-Co layered double hydroxide (LDH) nanowires with stainless steel mesh as supporter (PES/PDA@ZNCNW-SSM). The PES/PDA@ZNCNW-SSM shows excellent underliquid dual superlyophobicity with underwater tetrachloroethylene contact angle and under n-hexane water contact angle of 166.7° and 166.8°, respectively. The underliquid dual lyophobic PES and microporous structure formed by Zn-Ni-Co LDH nanowires synergistically contribute to the underliquid dual superlyophobic surface, which is beneficial for effective and controllable organic liquid/water separation. After 10 cycles of alternate separation, the separation efficiencies of PES/PDA@ZNCNW-SSM are above 99.9% and 99.4% for water-in-tetrachloroethylene and tetrachloroethylene-in-water emulsions, respectively. The underliquid dual superlyophobicity can also be obtained with carbon cloth, non-woven fabric, Ni foam and filter paper as supporter and the corresponding membranes can be used to efficiently separate organic liquid/water mixtures on-demand. These results confirm that the hierarchical micro/nanostructure anchored with underliquid dual lyophobic PES nanoparticles is an effective route for the preparation of underliquid dual superlyophobic materials. [ABSTRACT FROM AUTHOR]

The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography. This bcc structure is in striking contrast with the fcc structure of bulk gold and conventional Au nanoparticles, as well as the bi-icosahedral structure of [Au38(SCH2CH2Ph)24]. The bcc nanocluster has a distinct HOMO-LUMO gap of ca. 1.5 eV, much larger than the gap (0.9 eV) of the bi-icosahedral [Au38(SCH2CH2Ph)24]. The unique structure of the bcc gold nanocluster may be promising in catalytic applications. [ABSTRACT FROM AUTHOR]

The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography. This bcc structure is in striking contrast with the fcc structure of bulk gold and conventional Au nanoparticles, as well as the bi-icosahedral structure of [Au38(SCH2CH2Ph)24]. The bcc nanocluster has a distinct HOMO-LUMO gap of ca. 1.5 eV, much larger than the gap (0.9 eV) of the bi-icosahedral [Au38(SCH2CH2Ph)24]. The unique structure of the bcc gold nanocluster may be promising in catalytic applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] A synthetic method for ultrasmall Pt nanoparticles (∼1nm) is developed. [•] Compared to bulk Pt, structural relaxation is observed in the Pt nanoparticles. [•] The Pt 4f core level energy shifts positively by +1eV compared with bulk Pt. [Copyright &y& Elsevier]

Carbon modified lithium titanate (Li4Ti5O12) anode nanocrystals for Li-ion batteries were synthesized by directly treating the titanium alkoxide and lithium acetate ethanol solution via the Reaction under Autogenic Pressure at Elevated Temperature (abbreviated to RAPET). The mixture of the liquid precursors decomposed during the RAPET process and then reacted in situ and transformed into carbon-modified Li4Ti5O12 anode nanocrystals. The organic moieties in the titanium alkoxide and the lithium salt provided both the oxygen and carbon for the synthesis. The resulting products were characterized by X-ray diffraction (XRD), elemental analysis, scanning electronic microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), nitrogen adsorption–desorption measurements, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge testing. The influences of the titanium alkoxide precursors, i.e. the length of the alkoxy group, on the properties of the final products and the presence of the in situ resulting carbon on the electrochemical performance have been investigated. [ABSTRACT FROM AUTHOR]

A series of [PdPyCl2]2(di-NHC) complexes were prepared (di-NHC are two 1-(2,6-dimethylphenyl)imidazolidene molecules bridged by an aliphatic -(CH2) n- linker ( n = 3, 4, 5, 6, and 10)). All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of four complexes ( n = 3, 4, 5 and 6) were determined by X-ray diffraction. The influence of the distant methyl group on the structural features and catalytic activity with increasing of length of linker was investigated by comparing the results of these 2,6-dimethylphenyl palladium complexes with those of their known mesityl analogues. X-ray studies show the distant methyl substitution has big impact on the structure feature of the complexes with the shorter linker between two NHC (ethylene and propylene), but has a little or no effect on that of the complexes with longer linker (butylene and hexylene). Catalytic results of the arylation of styrene show that the remote substitute has big effect on the regioselectivity of the product in all complexes with shorter and longer linkers, but has a limited effect on the yield. [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]

palladium complexes of ferrocenyl-functionalized N-heterocyclic carbenes with different substituents were synthesized. The molecular structures of selected complexes were determined by X-ray diffraction and show a pseudo-square-planar structure with a central palladium atom surrounded by carbene, pyridine, and two chloride ligands. The influence of the different substituents on the structure and reactivity of the complexes was studied. The catalytic properties of the complexes were investigated in the Larock indolization reactions of 2-bromoanilines with diphenylacetylene. Their performances slightly varied in this reaction, but the complex with mesityl substituent showed the best activity. [ABSTRACT FROM AUTHOR]

Abstract: Reactions of different alkane-bridged (n =1–3) di-NHC precursors, bisimidazolium chlorides with the NiCl2 in presents of K2CO3 in acetonitrile give the corresponding 16-electron binuclear complexes of the type Ni(di-NHC)(μ-O)2CO in moderate yield. The molecular structures of 1–3 have been determined by X-ray crystallography, which revealed a cis-chelating di-NHC on a slightly distorted square-planar nickel center with κ2-cabonato ligand. The influence of the different di-NHC ligands on the structure and reactivity of the complexes has been studied. The catalytic properties of the complexes were investigated in the Kumada reaction for cross-coupling of phenylmagnesium bromide with a variety of aryl halides. The complex 3 which has the longest linker between two NHCs shows the best catalytic activity in these reactions. [Copyright &y& Elsevier]

A series of imidazole-based and benzimidazole-based di-NHC dipalladium complexes with alkyl bridges of different chain lengths were prepared. All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of three complexes were determined by X-ray diffraction. X-ray studies show the length of linker effects the solid structure of these complexes and π-π stacking plays an important role for the configuration of NHC-Pd-Py subunits. The activity of NHC-palladium complexes was investigated in the mono- and double-Heck reactions, and the imidazole-based palladium complex bearing the shortest ethylene bridge shows the best activity and selectivity in both reactions. [ABSTRACT FROM AUTHOR]

Air-stable metallic Co nanoparticles were incorporated into the pores or anchored onto the external surface of an ordered mesporous carbon/SBA-15 composite by simply treating the cobalt precursor-impregnated surfactant-containing SBA-15 via the Reaction under Autogenic Pressure at Elevated Temperature (abbreviated to RAPET) process, resulting in bifunctional Co@carbon/SBA-15 composites. Surfactant-containing mesoporous SBA-15 (denoted as surf-SBA-15 composite) was firstly impregnated with a cobalt precursor solution and then calcined under autogenic pressure at elevated temperature using a Swagelok-like high-temperature autoclave in an N2 atmosphere. During the RAPET process, the cobalt precursor impregnated into the channel of the surf-SBA-15 composites decomposed and was reduced by the surfactant species, meanwhile, the surfactant, which was used as a soft template for the formation of mesoporous silica, was carbonized and coated onto the internal and the external surface of mesoporous silica and partially onto the incorporated metallic Co nanoparticles, forming Co nanoparticles encapsulated by a mesoporous carbon/SBA-15 composite (mesoporous Co@carbon/SBA-15) in situ. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption–desorption measurements and X-ray diffraction (XRD). The influences of the concentration of cobalt precursors on the morphologies and the magnetic properties of the mesoporous Co@carbon/silica composites were studied. The adsorption/separation ability of the magnetic mesoporous composite to organic guest molecules and the stability of the nanosized metallic Co decorations in air or in an acid environment were also investigated. [ABSTRACT FROM AUTHOR]

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]

A series of N-aryl or N-methyl substituted bisimidazolium dichloride or dibromide salts with different alkyl bridge lengths (n = 1–4) have been synthesized starting from N-arylimidazoles or N-methylimidazoles with dialkyl bromides or the less expensive but less reactive dialkyl chlorides under solvent-free conditions. This green protocol provided most bisimidazolium chloride and bromide salts in good yields, and the reaction time was shortened to a few hours. In two examples, we showed either bisimidazolium dichloride (1a) or dibromide salt (3c) can be easily converted to the corresponding dihexafluorophosphate salt (1a′ or 3c′) in near quantitative yield. [ABSTRACT FROM PUBLISHER]

An efficient C-N coupling reaction of aryl chlorides or bromides with imidazole was successfully performed with cheap and commercially available catalytic system Cu(I)/HMTA. Both aryl bromides and aryl chlorides have been effectively catalyzed by Cu/HMTA, giving products in moderate to good yields. Moreover, aryl halides bearing either electron-withdrawing groups or electron-donating groups could be used in the reaction. [image omitted] [ABSTRACT FROM AUTHOR]

Abstract: A series of di-NHC ligands with alkyl bridges of different chain lengths (n =2–4) and their bi-palladium complexes (4, 5 and 6) have been prepared. The molecular structure of 4 and 6 were determined by X-ray diffraction studies. The structures of complex 4 consist of two pseudo-square-planar subunits in a trans configuration, however 6 consist of two subunits in a cis configuration with π–π stacking between two pyridines. The influence of the different bridges on the structure and reactivity of the complexes has been studied. The catalytic activity of the new binuclear palladium complexes was successfully tested in the Mizoroki–Heck reaction of styrene with bromobenzene. The complex with 2 and 4 carbon linker gave higher yield, while the one with 3 carbon linker gave better regioselectivity. [ABSTRACT FROM AUTHOR]

Abstract: Hydrothermal synthesis, characterization and magnetic properties of a series of ABO3-perovskites LaFe1−x Cr x O3 (0≤x≤1) are reported. The alkalinity in initial reaction mixtures plays a critical role in controlling the designed stoichiometry of the final compositions. Their magnetic properties are strongly dependent on the compositions and a maximum magnetic moment is found for the sample at x=0.5. Weak ferromagnetic interaction observed for the samples from x=0 to 0.9 arises from the presence of Fe–O–Fe antisymmetric exchange and Fe–O–Cr superexchange interaction. The weak ferromagnetism as well as the linear variation of the lattice parameters implies the possible random distribution of Fe and Cr ions in B sites of the perovskites. The evolution of magnetic ordering transition temperatures has a close relationship with substituent ratios, for the competition of antiferromagnetism and ferromagnetism. The saturated magnetic moment shows a great improvement compared with that for the samples synthesized by solid state method. [Copyright &y& Elsevier]

[Display omitted] • MoS 2 /CuS nanosheets coated brass mesh is prepared via a facile hydrothermal method. • The underliquid dual superlyophobicity is good for organic solvent/water separation. • The unusual superwettability is attributed to the MoS 2 /CuS nanosheets structure. • The MoS 2 /CuS mesh is stable in acidic or alkaline solutions with the pH of 1–13. MoS 2 /CuS nanosheets coated on brass mesh with switchable superwettability have been prepared through a facile hydrothermal method. The MoS 2 /CuS coated mesh shows excellent underwater superlyophobicity and underliquid superhydrophobicity for gravity-driven immiscible organic solvent/water mixtures separation. Switchable permeation function of water-removing or organic solvent-removing can be achieved by water or organic solvent pre-wetted mesh. After 20 cycles of organic solvent/water separation, the MoS 2 /CuS coated mesh demonstrates high separation efficiency above 99.5% for both of cyclohexane/water mixture and tetrachloroethylene/water mixture. The MoS 2 /CuS coated mesh presents satisfactory chemical stability under acidic or alkaline conditions in the pH range of 1–13. The switchable superwetting property and chemical stability make it possible to be a potential candidate in separation of immiscible organic solvent/water mixture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chitosan modified hydrogen titanate nanowires membranes are prepared. • The membrane shows excellent adsorption capacity and removal rate for anionic dyes. • The membrane maintains stability during 15 cycles of adsorption–desorption. Chitosan modified hydrogen titanate nanowires membrane is prepared through a simple immersion-filtration method, which can be used to adsorb anionic dyes. The adsorption kinetics data shows that the adsorption process follows the pseudo-second-order model. Thermodynamics analysis reveals the adsorption is a spontaneous process. During the dynamic adsorption process, chitosan modified hydrogen titanate nanowires membrane shows excellent removal rate of 99.5% and adsorption capacity of 374.4 mg g−1 for Congo red. The membrane exhibits excellent cyclic adsorption performance and satisfactory removal rate in the pH range of 2.5–12.5. After 15 adsorption–desorption cycles, the removal rate and permeability of Congo red remain above 98.7% and 1120.0 L m-2h−1 bar−1, respectively. [ABSTRACT FROM AUTHOR]

Perovskite oxides have provided magical structural models for superconducting and colossal magnetoresistance, and the search for nano-scale and/or atomic-scale devices with particular property by specific preparations in the same systems has been extensively conducted. We present here the three oxidation states of manganese (Mn3+, Mn4+, Mn5+) in the perovskite oxide, La0.66Ca0.29K0.05MnO3, which most interestingly shows the rectifying effect as atomic-scale p–n junctions (namely FY-Junctions) of single crystals and films. The family of cubic perovskite oxides were synthesised by the so-called hydrothermal disproportionation reaction of MnO2 under the condition of strong alkali media. The new concept of the atomic-scale p–n junctions, based on the ideal rectification characteristic of the p–n junctions in the single crystal, basically originates from the structural linkages of [Mn3+–O–Mn4+–O–Mn5+], where Mn3+ $$ {\left( {{\text{t}}^{{\text{3}}}_{{{\text{2g}}}} {\text{e}}^{1}_{{\text{g}}} } \right)} $$ and Mn5+ $$ {\left( {{\text{t}}^{{\text{2}}}_{{{\text{2g}}}} {\text{e}}^{{\text{0}}}_{{\text{g}}} } \right)} $$ in octahedral symmetry serve as a donor and an acceptor, respectively, corresponding to the localized Mn4+ $$ {\left( {{\text{t}}^{{\text{3}}}_{{{\text{2g}}}} {\text{e}}^{{\text{0}}}_{{\text{g}}} } \right)} $$ . [ABSTRACT FROM AUTHOR]