Preparation of Yolk‐Shell and Filled Co9S8 Microspheres and Comparison of their Electrochemical Properties

In this study, we report the first preparation of phase‐pure Co₉S₈ yolk–shell microspheres in a facile two‐step process and their improved electrochemical properties. Yolk–shell Co₃O₄ precursor microspheres are initially obtained by spray pyrolysis and are subsequently transformed into Co₉S₈ yolk–shell microspheres by simple sulfidation in the presence of thiourea as a sulfur source at 350 °C under a reducing atmosphere. For comparison, filled Co₉S₈ microspheres were also prepared using the same procedure but in the absence of sucrose during the spray pyrolysis. The prepared yolk–shell Co₉S₈ microspheres exhibited a Brunauer–Emmett–Teller (BET) specific surface area of 18 m² g^?1 with a mean pore size of 16 nm. The yolk–shell Co₉S₈ microspheres have initial discharge and charge capacities of 1008 and 767 mA h g^?1 at a current density of 1000 mA g^?1, respectively, while the filled Co₉S₈ microspheres have initial discharge and charge capacities of 838 and 638 mA h g^?1, respectively. After 100 cycles, the discharge capacities of the yolk–shell and filled microspheres are 634 and 434 mA h g^?1, respectively, and the corresponding capacity retentions after the first cycle are 82 % and 66 %.     

Catalytic Activity of Molecular Rhenium Sulfide Clusters [Re6S8(OH)6−n (H2O) n ](4−n)− (n = 0, 2, 4, 6) with Retention of the Octahedral Metal Frameworks: Dehydrogenation and Dehydration of 1,4-Butanediol

A series of molecular rhenium sulfide clusters [Re₆S₈(OH)_6?n (H₂O) _n ]^(4?n)? (n = 0, 2, 4, 6) catalyze dehydrogenation of alcohols, and hydrogenation of ketones and olefins in a hydrogen stream at 350 °C. The catalytic activities of the dianionic and neutral clusters (n = 2, 4) are lower than those of tetraanionic and dicationic clusters (n = 0, 6) for all the reactions. When 1,4-butanediol is allowed to react over K₄[Re₆S₈(OH)₆], dehydrogenation proceeds to yield 2-hydroxytetrahydrofuran and successively γ-butyrolactone above 300 °C. Over [Re₆S₈(H₂O)₆]SO₄ dehydration proceeds to yield tetrahydrofuran above 250 °C. The thermal activation mechanisms of these clusters were studied by powder X-ray diffraction analyses, Raman spectrometry, extended X-ray absorption fine structure spectrometry, thermogravimetry, and differential thermal analyses. The catalytically active site of K₄[Re₆S₈(OH)₆] is an uncoordinated metal site (Lewis acid site) developed by the loss of a water molecule from two hydroxo ligands. The active site of [Re₆S₈(H₂O)₆]SO₄ is a Brønsted acid site; the anhydrous aqua cluster dication disproportionates to a hydroxo cluster monocation and a proton. Both of the octahedral cluster frameworks are retained up to 500 °C.     

Synthesis and characterization of platinum and palladium pyrrolidinedithiocarbamate complexes

Treatment of (PPh₃)₂MCl₂ (M = Pd or Pt) with ammonium pyrrolidinedithiocarbamate (NH₄S₂CNC₄H₈) in a 1:1 molar ratio gave (PPh₃)M(Cl)(κ ² S,S-S₂CNC₄H₈) [M = Pt (1), Pd (2)]. On the other hand, the interaction of these compounds in a 1:2 [M:L] molar ratio gave (PPh₃)Pt(κS-S₂CNC₄H₈)(κ ² S,S-S₂CNC₄H₈) (3), which contains both terminal and chelated dithiocarbamato ligands, or a yellow insoluble solid for M = Pd. The bis(diphenylphosphino)ethane platinum or palladium dichlorides [(dppe)MCl₂] reacted with the same ligand to give the salts [(dppe)M(κ ² S,S-S₂CNC₄H₈)]Cl (M = Pt (4), Pd (5) which have only one chelating dithiocarbamato ligand. The new compounds were characterized by ¹H-, ¹³C{¹H}- and ³¹P-n.m.r. spectroscopy, mass spectrometry, elemental analysis and X-ray single crystal structure analysis.     

Radiolytic synthesis of BaSO4 microspheres

The solid BaSO₄ microspheres, mainly consisting of quasi-spherical nanoparticles, were successfully synthesized by precipitating Ba²⁺ ions with SO₄²⁻ ions, which were generated from the reduction of K₂S₂O₈ in the presence of EDTA under N₂ atmosphere by γ-irradiation. It was found that the controlled release of SO₄²⁻ played an important role in the formation of the microspheres.     

Preparation of Thermosensitive Hollow Imprinted Microspheres via Combining Distillation Precipitation Polymerization and Thiol‐ene Click Chemistry

Hollow molecular imprinted polymer microspheres were prepared by distillation precipitation polymerization with (S)‐(+)‐ibuprofen (S‐IBF) as template molecule and acrylamide (AM) as functional monomer. Using the silicon dioxide (SiO₂, 180 nm) modified by 3‐(trimethoxysilyl)propyl methacrylate (MPS) as the template microspheres, the molecular imprinted shells were coated on successfully (SiO₂@MIPs). The thermosensitive SiO₂@MIPs‐PNIPAM core‐shell microspheres were subsequently prepared by grafting the PNIPAM chains (M_n=1.21×10⁴ g/mol, polydispersity index=1.30), which were prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization, on the surface of SiO₂@MIPs microspheres via the thiol‐ene click chemistry. The grafting density of PNIPAM brushes on the SiO₂@MIPs microspheres was about 0.18 chains/nm². After HF etching, the hollow imprinted microspheres were finally obtained. For thermosensitivity analysis, the phase transition temperatures of multifunctional nanoparticles were measured by DSL at 25°C and 45°C respectively, and the sizes of the microspheres changed by about 35 nm. The modified microspheres presented excellent controlled release property to S‐IBF, moreover about half amount of the adsorptions passed into acetonitrile‐water solution through the specific holes of imprinted shell at 25°C under vibration.     

Molybdic acid doped polyaniline micro/nanostructures via a self-assembly process

Molybdic acid (H₂MoO₄, MA) doped polyaniline (PANI) micro/nanostructures were prepared by a self-assembly process in the presence of ammonium persulfate ((NH₄)₂S₂O₈, APS) as the oxidant. The morphology of PANI-MA changed from nanofibers or nanotubes (～160 nm in diameter) to co-existence of nanofibers and microspheres (～3 μm in diameter) and that accompanied an enhancement of the conductivity from 5.42 × 10^?3 S cm^?1 to 2.8 × 10^?1 S cm^?1as the molar ratio of MA to aniline varied from 0.01 to 1.5. With increasing the polymerization time, moreover, the pH value of the reaction solution not only decreased due to sulfuric acid produced during the course of the polymerization, but also accompanied a change in morphology from microspheres to nanofibers. All above-mentioned observations could be interpreted by spherical and cylindrical micelle composed of MA as the “soft-template” in forming the micro/nanostructures.     

Construction of porous NiCo2S4@CeO2 microspheres composites for high-performance pseudocapacitor electrode by morphology reshaping

NiCo₂S₄ microspheres consisting of nanoparticles were synthesized by a simple hydrothermal process, and then NiCo₂S₄@CeO₂ microspheres consisting of nanosheets or nanoneedles-like structures were constructed by a morphology reshaping process for the first time. The introduction of CeO₂ changes the nanoparticle morphology of NiCo₂S₄, and forms incompact nanosheet and nanoneedle structures. The porous, incompact nanosheet or nanoneedle structures with enhanced specific surface areas not only accelerate the charge transfer but also facilitate the electrolyte diffusion and provide more active sites for the redox reactions. These merits endow outstanding electrochemical performances to NiCo₂S₄@CeO₂ microspheres when used as electrode materials for electrochemical pseudocapacitor. Especially, NiCo₂S₄@CeO₂ (6 wt%) microspheres consisted of nanosheets show a high specific capacitance of 1263.6 F g^?1 with a retention rate of 81.1% at 20 A g^?1 after 10,000 cycles. Nonetheless, pristine NiCo₂S₄ microspheres consisted of nanoparticles only show a high specific capacitance of 555.2 F g^?1 with a retention rate of 63.5% at the same conditions. The first-principles calculation shows that the strong interactions between the NiCo₂S₄ and CeO₂ are favorable for the stabilization of the composite, being responsible for its good cycling performance. The result shows that the NiCo₂S₄@CeO₂ microspheres are promising electrode materials for high-performance pseudocapacitor, and morphology reshaping and CeO₂ modification are efficient ways to construct high-performance pseudocapacitor.     

Hierarchical porous CoMn<Subscript>2</Subscript>O<Subscript>4</Subscript> microspheres with sub-nanoparticles as advanced anode for high<Emphasis Type="Bold">-</Emphasis>performance lithium<Emphasis Type="Bold">-</Emphasis>ion batteries

To deal with the large volume change for lithium-ion batteries (LIBs), we illustrate the synthesis of CoMn₂O₄ microspheres with sub-nanoparticles by a hydrothermal method followed by thermal treatment. The size of microsphere is approximately 2.2 μm, and the sub-nanoparticle is about 17 nm. There is sufficient void space between CoMn₂O₄ microspheres with sub-nanoparticles for ensuring the well structural integrity. As advanced anode for LIBs, CoMn₂O₄ microspheres display stable specific capacity retention of 772 mAh g^?1 over 500 cycles at a current density of 100 mA g^?1. Such a kind of structure is beneficial for enhanced rate and cycling capabilities in LIBs applications, which could increase contact area between electrolyte and active materials, short path for lithium ions and electrons and accommodate the volume change with additional void space during cycling. It has a great application prospect for use as electrochemical energy storage because of the enhanced performance.     

Hierarchical Hollow Co9S8 Microspheres: Solvothermal Synthesis,Magnetic, Electrochemical,and Electrocatalytic Properties

A simple solvothermal route in a binary solution of triethylenetetramine (TETA) and deionized water (DIW) has been used to synthesize hierarchical hollow Co₉S₈ microspheres with high surface area (80.38 m² g^?1). An appropriate volume ratio of TETA:DIW has been found to be essential for the formation of hollow Co₉S₈ microspheres. The magnetic study indicated that the Co₉S₈ hollow microspheres are paramagnetic at high temperature and antiferromagnetic at low temperature. The oxygen reduction reaction experiments demonstrated that the onset potential of the Co₉S₈ sample is 0.88 V, which is comparable to the value predicted for Co₉S₈ (0.74 V) from the theoretical simulation. The discharge capability of Co₉S₈ hollow microspheres as cathode materials for lithium ion batteries and their electrocatalytic activity for the oxygen reduction reaction (ORR) have been studied.     

Direct fabrication of anatase TiO<Subscript>2</Subscript> hollow microspheres for applications in photocatalytic hydrogen evolution and lithium storage

Hollow titanium dioxide (TiO₂) microspheres were synthesized in one step by employing tetrabutyl orthotitanate (TBOT) as a precursor through a facile solvothermal method in the presence of NH₄HCO₃. XRD analysis indicated that anatase TiO₂ can be obtained directly without further annealing. TiO₂ hollow microspheres with diameters in the range of 1.0–4.0 μm were confirmed through SEM and TEM measurements. The specific surface area was measured to be 180 m² g^?1 according to the nitrogen adsorption–desorption isotherms. Superior photocatalytic performance and good lithium storage properties were achieved for resultant TiO₂ samples. The H₂ evolution rate of the optimal sample is about 0.66 mmol h^?1 after loaded with 1 wt.% Pt (20 mg samples). The reversible capacity remained 143 mAh g^?1 at a specific current of 300 mA g^?1 after 100 charge–discharge cycles. This work provides a facile strategy for the preparation of hollow titanium dioxide microspheres and demonstrates their promising photocatalytic H₂ evolution and the lithium storage properties.

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Graphical abstract Hollow titanium dioxide spheres are directly synthesized via a facile template-free solvothermal method with the presence of NH₄HCO₃ based on inside-out Ostwald ripening (see picture), and demonstrated both as a photocatalyst for water splitting and a promising anode material for lithium-ion batteries. Superior photocatalytic performance and excellent lithium storage properties are achieved for resultant TiO₂ hollow microspheres.

     

A Novel Tantalum Cluster Chalcohalide Ta4S1.5Se7.5I8

Single crystals of Ta₄S_1.5Se_7.5I₈ are obtained by heating Ta, S, Se and I₂ at 300 °C in 4.0:1.0:8.0:4.4 molar ratio. The structure was determined by X-ray analysis and consists of molecular clusters [Ta₄(μ₄-S)(μ₂-Q_axSe_eq)₄I₈] (Q ≈ Se_0.87S_0.13). The tantalum atoms form a square with long Ta…Ta distances (3.26–3.32 Å), with four dichalcogenide ligands bridging the Ta–Ta edges and a sulfur atom capping the square. Each Ta atom has two terminal iodine atoms. Raman spectroscopy study shows the presence of the characteristic absorption band at 396 cm^?1 which is due to the Ta₄–μ₄-S vibrations. Cyclic voltammetry shows that Ta₄S_1.5Se_7.5I₈ in solid state undergoes quasi-reversible one-electron oxidation which is metal-centered.     

A Novel Tantalum Cluster Chalcohalide Ta4S1.5Se7.5I8

Single crystals of Ta₄S_1.5Se_7.5I₈ are obtained by heating Ta, S, Se and I₂ at 300 °C in 4.0:1.0:8.0:4.4 molar ratio. The structure was determined by X-ray analysis and consists of molecular clusters [Ta₄(μ₄-S)(μ₂-Q_axSe_eq)₄I₈] (Q ≈ Se_0.87S_0.13). The tantalum atoms form a square with long Ta…Ta distances (3.26–3.32 Å), with four dichalcogenide ligands bridging the Ta–Ta edges and a sulfur atom capping the square. Each Ta atom has two terminal iodine atoms. Raman spectroscopy study shows the presence of the characteristic absorption band at 396 cm^?1 which is due to the Ta₄–μ₄-S vibrations. Cyclic voltammetry shows that Ta₄S_1.5Se_7.5I₈ in solid state undergoes quasi-reversible one-electron oxidation which is metal-centered.     

Macrocyclic Inorganic Tin-Containing Oxo Clusters: Heterometallic Strategy for Configuration and Catalytic Activity Modulation

In this work, the first examples of inorganic macrocyclic tin-oxo clusters which are stabilized by sulfate ligands are reported. As determined by X-ray diffraction and photoelectron spectroscopy analyses, the prepared inorganic Sn₁₀-oxo cluster displays interesting mixed valence behaviors, with 8 Sn⁴⁺ located at the cyclic skeleton and two Sn²⁺ encapsulated in the center. When further introducing Ti⁴⁺ and In³⁺ ions to the synthetic systems, heterometallic Sn₂Ti₆ and SnIn₅Ti₆ complexes with Ti₆(SO₄)₉ and SnIn₅(SO₄)₁₂ macrocyclic skeletons were prepared whose configuration and packing models were affected by the ionic radius of incorporated metals. Moreover, comparative CO₂ reduction experiments confirm that such heterometallic composition can significantly improve the catalytic activities of these inorganic macrocyclic oxo clusters. This work represents a milestone in constructing inorganic tin complexes and also macrocyclic metal oxo clusters with tunable configurations and properties.     

Preparation and characterization of aqueous stable electro-spun nanofibers using polyvinyl alcohol/polyvinyl pyrrolidone/zeolite

Cross-linked polyvinyl alcohol/polyvinyl pyrrolidone/zeolite fibers were prepared in the presence of potassium peroxodisulphate (K₂S₂O₈) under the curing process by the electrospinning technique. The narrowest nanofibers of PVA/PVP (50:50) were prepared under optimum experimental conditions of 2.5 × 10^?4 mol of K₂S₂O₈, an applied voltage of 22 KV, the distance of 15 cm and the feed rate of 0.2 mL/h. The progress of the cross-linking was examined by immersion of the prepared nanofibers in water and following the swelling degrees. By raising the K₂S₂O₈ amount and curing time, the cross-linking density was increased. X-ray diffraction (XRD) demonstrated that the crystallinity of the nanofibers was decreased by the increase of K₂S₂O₈ and the lowest crystallinity was observed for PVA/PVP (70:30). The contact angle of nanofibers was decreased from 72° to 34 by increasing PVP ratio from 30 to 70. The morphology of the nanofibers before and after immersion in the simulated body fluid (SBF) was studied using electron scanning microscopy (SEM) and PVA/PVP (70:30) showed the highest changes in the morphology while the lowest one was observed for PVA/PVP (50:50). Moreover, the cross-linked PVA/ PVP with the ratio of 50:50 had the narrowest diameter of 200 ± 100 nm, and by addition of about 0.5% zeolite, it was even reduced more to 150 ± 50 nm. The cross-linked nanofibers (50:50) with 0.5 wt% and 1.5 wt% zeolite nanoparticles showed the tensile modules of 416.26 and 703.52 MPa, respectively, while in the absence of zeolite, it was209.25 MPa. Fibroblast L929 cells were cultured on the cross-linked PVA/PVP/zeolite (50:50:0.5) nanofiber, and the cell proliferation and growth was evaluated by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Fibroblasts grew on the surface of scaffold showed good morphology and proliferation after seven days and the absorption amount was increased from 0.075 to 0.78     

Supramolecular Adduct of γ-Cyclodextrin and [{Re<Subscript>6</Subscript>Q<Subscript>8</Subscript>}(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>]<Superscript>2+</Superscript> (Q=S,Se)

Slow evaporation of water solution of [{Re₆S₈}(H₂O)₆]²⁺ generated in situ from [{Re₆S₈}(OH)₆]^4– in presence of γ-cyclodextrin (CD) leads to crystallization of {[{Re₆S₈}(H₂O)₆] ? [γ-CD]}(NO₃)₂·12H₂O (1·12H₂O) supramolecular complex, which was characterized by single-crystal X-ray diffraction crystallography, IR-spectroscopy, thermogravimetric and elemental analyses. X-ray analysis confirms the formation of 1:1 {[{Re₆S₈}(H₂O)₆] ? [γ-CD]}²⁺ inclusion compound in the solid state. However, no adduct formation was detected between [{Re₆S₈}(H₂O)₆]²⁺ and γ-cyclodextrin in solution, according to ¹H NMR spectroscopy. In the case of in situ generated [{Re₆Se₈}(H₂O)₆]²⁺ the reaction solution with γ-cyclodextrin is unstable and during the crystallization only amorphous precipitate has been obtained.     

Purification, Characterization, and Specificity Determination of a New Serine Protease Secreted by Penicillium waksmanii

The purpose of this work was to purify a protease from Penicillium waksmanii and to determine its biochemical characteristics and specificity. The extracellular protease isolated that was produced by P. waksmanii is a serine protease that is essential for the reproduction and growth of the fungus. The protease isolated showed 32 kDa, and has optimal activity at pH 8.0 and 35 °C towards the substrate Abz-KLRSSKQ-EDDnp. The protease is active in the presence of CaCl₂, KCl, and BaCl, and partially inhibited by CuCl₂, CoCl₂ and totally inhibited by AlCl₃ and LiCl. In the presence of 1 M urea, the protease remains 50 % active. The activity of the protease increases 60 % when it is exposed to 0.4 % nonionic surfactant-Triton X-100 and loses 10 % activity in the presence of 0.4 % Tween-80. Using fluorescence resonance energy transfer analysis, the protease showed the most specificity for the peptide Abz-KIRSSKQ-EDDnp with k _cat/K _m of 10,666 mM^?1?s^?1, followed by the peptide Abz-GLRSSKQ-EDDnp with a k _cat/K _m of 7,500 mM^?1?s^?1. Basic and acidic side chain-containing amino acids performed best at subsite S₁. Subsites S₂, S₃, S^′ ₂, and S^′ ₁, S^′ ₃ showed a preference for binding for amino acids with hydrophobic and basic amino acid side chain, respectively. High values of k _cat/K _m were observed for the subsites S₂, S₃, and S^′ _2. The sequence of the N-terminus (ANVVQSNVPSWGLARLSSKKTGTTDYTYD) showed high similarity to the fungi Penicillium citrinum and Penicillium chrysogenum, with 89 % of identity at the amino acid level.     

Fabrication of high-performance supercapacitors based on hollow SnO2 microspheres

Hollow SnO₂ microspheres are prepared from resorcinol–formaldehyde gel and different tin compound precursors, including stannous sulfate (SnSO₄), stannous chloride dihydrate (SnCl₂·2H₂O), and stannic chloride pentahydrate (SnCl₄·5H₂O) via chemically induced self-assembly in hydrothermal environment. Morphological and structural characterizations of as-prepared hollow SnO₂ microspheres are carried out using scanning electron microscopy, X-ray diffraction, and nitrogen adsorption–desorption method. Their electrochemical properties as the supercapacitor electrode materials for application are also investigated using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurement in 1 M H₂SO₄ electrolyte. There are redox peaks in CV curves and a large number of Faradic plateaus in GCD curves. At different scan rates, all the obtained samples have excellent electrochemical properties. The hollow SnO₂ microspheres obtained from SnSO₄ and SnCl₂·2H₂O as precursors show relatively lower specific capacitances of 395 and 347 F g^?1, respectively. However, the specific capacitance of SnO₂ from SnCl₄·5H₂O is up to 663 F g^?1. The high specific surface area and hollow structure of SnO₂ microspheres are due to facilitating the rapid transport of electrolyte ions and improving the electrochemical performance. It is expected that hollow SnO₂ microspheres are the promising redox supercapacitor materials.     

Low-temperature heat capacities, and thermodynamic properties of solid–solid phase change material bis(1-octylammonium) tetrachlorocuprate

A new crystalline complex (C₈H₁₇NH₃)₂CuCl₄(s) (abbreviated as C₈Cu(s)) was synthesized by liquid phase reaction. Chemical analysis, elemental analysis, and X-ray crystallography were applied to characterize the composition and crystal structure of the complex. Low-temperature heat capacities of the complex were measured by a precision automatic adiabatic calorimeter over the temperatures ranging from 78 to 395 K, and two solid–solid phase changes appeared in the heat capacity curve. The temperatures, molar enthalpies and entropies of the two phase transitions of the complex were determined to be: T _{trs, 1} = 309.4 ± 0.35 K, Δ_trs H _{m, 1} = 16.55 ± 0.41 kJ mol^?1, and Δ_trs S _{m, 1} = 53.49 ± 1.3 J K^?1 mol^?1 for the first peak; T _{trs, 2} = 338.5 ± 0.63 K, Δ_trs H _{m, 2} = 6.500 ± 0.10 kJ mol^?1, and Δ_trs S _{m, 2} = 19.20 ± 0.28 J K^?1 mol^?1 for the second peak. Two polynomial equations of the heat capacities as a function of the temperature were fitted by least-square method. Smoothed heat capacities and thermodynamic functions of the complex relative to the standard reference temperature of 298.15 K were calculated based on the fitted polynomial equations.     

A high mass loading electrode based on ultrathin Co<Subscript>3</Subscript>S<Subscript>4</Subscript> nanosheets for high performance supercapacitor

There is a growing need for the electrode with high mass loading of active materials, where both high energy and high power densities are required, in current and near-future applications of supercapacitor. Here, an ultrathin Co₃S₄ nanosheet decorated electrode (denoted as Co₃S₄/NF) with mass loading of 6 mg cm^?2 is successfully fabricated by using highly dispersive Co₃O₄ nanowires on Ni foam (NF) as template. The nanosheets contained lots of about 3～5 nm micropores benefiting for the electrochemical reaction and assembled into a three-dimensional, honeycomb-like network with 0.5～1 μm mesopore structure for promoting specific surface area of electrode. The improved electrochemical performance was achieved, including an excellent cycliability of 10,000 cycles at 10 A g^?1 and large specific capacitances of 2415 and 1152 F g^?1 at 1 and 20 A g^?1, respectively. Impressively, the asymmetric supercapacitor assembled with the activated carbon (AC) and Co₃S₄/NF electrode exhibits a high energy density of 79 Wh kg^?1 at a power density of 151 W kg^?1, a high power density of 3000 W kg^?1 at energy density of 30 Wh kg^?1 and 73 % retention of the initial capacitance after 10,000 charge-discharge cycles at 2 A g^?1. More importantly, the formation process of the ultrathin Co₃S₄ nanosheets upon reaction time is investigated, which is benefited from the gradual infiltration of sulfide ions and the template function of ultrafine Co₃O₄ nanowires in the anion-exchange reaction.

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Graphical abstract The ultrathin 2D Co₃S₄ nanosheets fabricated on 3D Ni foam and the formation process of the ultrathin Co₃S₄ nanosheets upon reaction times has been investigated. At the same time, the Co₃S₄/NF electrode displays an outstanding specific capacitance of 2420 F g^?1 at 1 A g^?1 with high mass loading of 6 mg cm^?2.

     

Synthesis,structure and luminescence properties of new chalcogenide octahedral rhenium cluster complexes with 4-aminopyridine [{Re6Q8}(4-NH2-py)6]2+

Two new cationic octahedral rhenium cluster complexes [{Re₆Q₈}(4-NH₂-py)₆]²⁺ (Q=S, Se; 4-NH₂-py = 4-aminopyridine) were synthesized by reactions of cesium salts of cluster anions [{Re₆Q₈}Br₆]^4?/3? with molten 4-aminopyridine. Both complexes were separated as salts with Br^? as counterions and the structure of [{Re₆S₈}(4-NH₂-py)₆]Br₂·6DMF was revealed by X-ray single-crystal diffraction analysis. The compounds were characterized by elemental analysis, energy dispersive X-ray, IR, NMR, and luminescence spectroscopies.