“Welcome-mat”-like porous Si/Cu composite amorphous films are fabricated by applying the predeposited Cu-nanoparticle-assembled film as the growth direction template for the subsequent deposition of a Si active layer with the cluster beam deposition technique. When used as the binder-free anodes for lithium ion batteries, the acquired single-layer porous Si/Cu composite film exhibits a large reversible capacity of 3124 mA h g–1 after 1000 cycles at 1 A g–1. Even when cycled at 20 A g–1 for 450 cycles, the porous Si/Cu composite film still delivers a decent reversible capacity of 2086 mA h g–1. Also, multilayer porous Si/Cu composite films are synthesized through layer-by-layer sputtering and exhibit outstanding cyclability and relatively high specific capacity and initial Coulombic efficiency irrespective of increasing the layer number from two to four layers. The reasons for the excellent electrochemical properties of single-layer and multilayer porous Si/Cu composite films are discussed in detail.Keywords: binder-free anode; copper granular films; lithium storage properties; multilayer films; porous structure; silicon;

ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmosphere. The electrochemical performance investigation suggests that the harvested ZnO–CuO porous hybrid microspheres illustrate much higher specific capacity and better cycling stability than single ZnO counterparts. A reversible capacity of 585 mAh·g−1 can be acquired for ZnO–CuO porous hybrid microspheres after cycling 500 times at a current density of 200 mA·g−1. The porous configuration and the incorporation of CuO are responsible for the enhanced lithium storage properties of ZnO–CuO hybrids.

•H-Fe3O4@RGO is synthesized by CTAB induced self-assembly method.•Fe3O4 nano-flowers are intimately encapsulated by 3D graphene network.•Synergistic effect improves the performances of H-Fe3O4@RGO.•High capacity of 2270 mA h g−1 after 460 cycles is achieved at 0.5 A g−1.Graphene-encapsulated hierarchical metal oxides architectures can efficiently combine the merits of graphene and hierarchical metal oxides, which are deemed as the potential anode material candidates for the next-generation lithium-ion batteries due to the synergistic effect between them. Herein, a cationic surfactant induced self-assembly method is developed to construct 3D Fe3O4@reduction graphene oxide (H-Fe3O4@RGO) hybrid architecture in which hierarchical Fe3O4 nano-flowers (H-Fe3O4) are intimately encapsulated by 3D graphene network. Each H-Fe3O4 particle is constituted of rod-shaped skeletons surrounded by petal-like nano-flakes that are made up of enormous nanoparticles. When tested as the anode material in lithium-ion batteries, a high reversible capacity of 2270 mA h g−1 after 460 cycles is achieved under a current density of 0.5 A g−1. More impressively, even tested at a large current density of 10 A g−1, a decent reversible capacity of 490 mA h g−1 can be retained, which is still higher than the theoretical capacity of traditional graphite anode, demonstrating the remarkable lithium storage properties. The reasons for the excellent electrochemical performance of H-Fe3O4@RGO electrode have been discussed in detail.Download high-res image (495KB)Download full-size image

•The porous Co/CoO microrods have been successfully fabricated by a facial method.•Large values of permittivity and permeability of Co/CoO-paraffin wax were obtained.•The porous Co/CoO microrods have excellent performance of microwave absorption at low frequency range with a small thickness.•The features of being “low density, small thickness, strong absorption and wide bandwidth” of absorber were achieved.Electromagnetic wave absorption materials with the features of being low density and porosity have attracted a great deal of attentions. In this manuscript, porous Co/CoO microrods were successfully synthesized through a facial and simple method. The resultant porous Co/CoO microrods exhibited superior microwave absorption properties because of their special structure. The high saturation magnetization of ferromagnetic metal Co component made the as-prepared composites have large relative complex permeability. The porous structures of materials improved the impedance match and enhanced the multiple reflections within the materials. With the 70 wt% of functional filler loading, the relative complex permittivity and permeability had significant increase due to the percolation effect. When the thickness of absorber is only 1.20 mm, the effective bandwidth is from 10.83 to 17.84 GHz covered almost Ku band (12–18 GHz). The minimum value of RL (−47.96 dB) was obtained at the frequency of 8.08 GHz with the thickness of only 1.76 mm. The result shows that this material can be used as a candidate for microwave absorption materials at low frequency range with a small thickness.Download high-res image (187KB)Download full-size image

•ZnO-Cu-C yolk-shell hybrid microspheres are prepared by a facile approach.•Yolk-shell hybrids show greatly strengthened lithium storage properties.•The notable battery properties of hybrids are due to their yolk-shell structures, Cu and C decoration.Zinc-copper citrate porous, yolk-shell and hollow microspheres are controllably produced via a facile electrostatic interplay between zinc citrate solid microspheres and copper sulphate solution with controllable concentration. By calcination of the firstly acquired zinc-copper citrate precursors in inert atmosphere, the corresponding ZnO-Cu-C porous, yolk-shell and hollow hybrid microspheres are synthesized. When adopted as the electrode materials for lithium ion batteries, the produced ZnO-Cu-C yolk-shell hybrid microspheres depict higher reversible capacity and better cycling stability than ZnO-Cu-C porous hybrid microspheres. After 500 cycles at 200 mA g−1, yolk-shell hybrids deliver a reversible capacity of 769 mA h g−1. Additionally, ZnO-Cu-C hollow hybrid microspheres exhibit best rate capability, which is due to their special three dimensional Cu conductive network.Download high-res image (124KB)Download full-size image

Transition metal phosphides (TMPs) have recently been thrust into the limelight as promising substitutes for precious noble metal-based cocatalysts for photocatalytic H2 evolution. Herein, colloidally synthesized Ni12P5 nanoparticles were successfully embedded into porous g-C3N4 nanosheets through a facile solution-phase approach under sonication. The as-prepared photocatalysts with an optimum 5 wt% anchoring of Ni12P5 (5NP-CN) displayed an excellent H2 production activity of 535.7 μmol g−1 h−1 under visible light irradiation. The high apparent quantum yield (AQY) of 4.67% at 420 nm was achieved in the 5NP-CN system for the production of H2, exceeding a large scientific spectrum of literature studies on the TMP-based catalysts. The superior photocatalytic H2 evolution of Ni12P5/g-C3N4 was predominantly attributed to the formation of intimate contact interfaces, in which Ni12P5 nanoparticles with high purity and good crystallinity were homogeneously embedded into the porous g-C3N4 nanosheets, thus facilitating the separation and transfer of photogenerated charge carriers. Meanwhile, a possible photocatalytic mechanism of Ni12P5/g-C3N4 hybrid nanocomposites was proposed and corroborated by photoluminescence (PL) spectroscopy and photoelectrochemical (PEC) results. As such, the present reported synthetic route to the g-C3N4-based photocatalysts incorporating Ni12P5 paves a new way for the advancement of g-C3N4 and a cornucopia of colloidal nanocrystals, which will be auspicious toward the nanoarchitecture engineering of noble-metal-free heterojunction interfaces for application in renewable energy production.

Magnetic metal-semiconductor hybrid nanocrystals containing ferromagnetic Ni and semiconductor ZnO have been prepared via a hot-injection route. The Ni-ZnO hybrid nanocrystals have a flower-like morphology that consists of Ni inner cores and ZnO petal shells. In spite of their large lattice mismatch, ZnO nanocrystals can still grow on faceted Ni nanocrystals to form stable interfaces. The composition of Ni-ZnO hybrid nanocrystals is readily controlled, and the average size of Ni core is tunable from 25 to 50 nm. Room temperature ferromagnetic properties are observed in these hybrid nanocrystals, and tunable magnetic properties also can be achieved by varying the size of Ni core. The as-prepared Ni-ZnO hybrid nanocrystals exhibit enhanced photocatalytic performance under ultraviolet light illumination as compared to pure ZnO nanocrystals. Furthermore, the superior reusability of hybrid nanocrystals for photocatalytic application is achieved by virtue of their magnetic properties. The facile and efficient seed-mediate strategy is particularly attractive to construct hybrid magnetic-semiconducting heterostructures. The as-obtained Ni-ZnO hybrid nanocrystals offer great potential for various applications due to their combined magnetic and semiconducting properties and low-cost earth-abundant availability.

•Fe-Cr nanocluster-assembled granular films were successfully prepared by a novel in situ assembly technology.•Conduction mechanism in Fe-Cr granular films was proposed.•Scattering effect contribution to resistivity in granular films was extract.•Anomalous Hall effect scaling relation in Fe-Cr granular films was studied.•The magnetoresistance effect in Fe-Cr granular films was investigated.The Fe100-xCrx nanocluster-assembled granular films with Cr atomic fraction (x) ranging from 0 to 100 were fabricated by using a plasma-gas-condensation cluster deposition system. The TEM characterization revealed that the uniform Fe clusters were coated with a Cr layer to form a Fe-Cr core-shell structure. Then, the as-prepared Fe100-xCrx nanoclusters were randomly assembled into a granular film in vacuum environments with increasing the deposition time. Because of the competition between interfacial resistance and shunting effect of Cr layer, the room temperature resistivity of the Fe100-xCrx nanocluster-assembled granular films first increased and then decreased with increasing the Cr atomic fraction (x), and revealed a maximum of 2 × 104 μΩ cm at x = 26 at.%. The temperature-dependent longitudinal resistivity (ρxx), magnetoresistance (MR) effect and anomalous Hall effect (AHE) of these Fe100-xCrx nanocluster-assembled granular films were also studied systematically. As the x increased from 0 to 100, the ρxx of all samples firstly decreased and then increased with increasing the measuring temperature. The dependence of ρxx on temperature could be well addressed by a mechanism incorporated for the fluctuation-induced-tunneling (FIT) conduction process and temperature-dependent scattering effect. It was found that the anomalous Hall effect (AHE) had no legible scaling relation in Fe100-xCrx nanocluster-assembled granular films. However, after deducting the contribution of tunneling effect, the scaling relation was unambiguous. Additionally, the Fe100-xCrx nanocluster-assembled granular films revealed a small negative magnetoresistance (MR), which decreased with the increase of x. The detailed physical mechanism of the electrical transport properties in these Fe100-xCrx nanocluster-assembled granular films was also studied.

Cu seeds were used to direct the epitaxial growth of Ni shell to form Cu–Ni core–shell cubes, tetrahexahedrons and nanowires. The controllable epitaxial growth of Ni shells on Cu cores provided selectively exposed surfaces and morphologies as well as tunable magnetic properties.

The preparation of magnetic metal nanocrystals with strong shape-anisotropy has attracted great research interest in recent years due to their unique applications in fields such as magnetic materials and catalysis. This paper explores a non-aqueous one-pot route to synthesizing triangular and hexagonal Ni nanosheets with an average edge length that can be reduced to 15 nm. In the synthesis, a widely used Ni precursor, nickel(II)acetylacetonate, is reduced by oleylamine in the presence of tungsten hexacarbonyl. An important aspect of such a synthetic strategy is that the nucleation temperature of the Ni nanocrystals can be as low as 150 °C. In the meantime, a shape-anisotropic nanostructure can be achieved. By increasing the reaction temperature and aging time, nanosheets with larger sizes are obtained. A possible formation mechanism is proposed for the as-prepared Ni nanosheets. Magnetic measurements show that all the prepared Ni nanosheets exhibit ferromagnetic characteristics at room temperature and larger magnetic anisotropy compared to spherical nanoparticles is evident.

Herein, we introduce a facile electrostatic attraction approach to produce zinc–silver citrate hollow microspheres, followed by thermal heating treatment in argon to ingeniously synthesize sandwich-like Ag-C@ZnO-C@Ag-C hybrid hollow microspheres. The 3D carbon conductive framework in the hybrids derives from the in situ carbonation of carboxylate acid groups in zinc–silver citrate hollow microspheres during heating treatment, and the continuous and homogeneous Ag nanoparticles on the outer and inner surfaces of hybrid hollow microspheres endow the shells with the sandwiched configuration (Ag-C@ZnO-C@Ag-C). When applied as the anode materials for lithium ion batteries, the fabricated hybrid hollow microspheres with sandwich-like shells reveal a very large reversible capacity of 1670 mAh g–1 after 200 cycles at a current density of 0.2 A g–1. Even at the very large current densities of 1.6 and 10.0 A g–1, the high specific capacities of about 1063 and 526 mAh g–1 can be retained, respectively. The greatly enhanced electrochemical properties of Ag-C@ZnO-C@Ag-C hybrid microspheres are attributed to their special structural features such as the hollow structures, the sandwich-like shells, and the nanometer-sized building blocks.Keywords: hybrid hollow microspheres; lithium storage properties; sandwich-like shells; silver; zinc oxide;

The functional synergy between the metal and the semiconductor in metal–semiconductor hybrid nanocrystals with specific structures and morphologies makes them suitable candidates for a wide range of applications. To date, the synthesis and the corresponding properties of ternary metal–semiconductor hetero-nanostructures, especially for hybrid nanocrystals containing magnetic metals, are seldom discussed and thus worthy of extensive research. In this study, we report a nonaqueous approach for the synthesis of Ni–Au–ZnO ternary hybrid nanocrystals with three morphologies, including nanomultipods, matchstick-like nanorods and nanopyramids. In the synthetic strategy, the Ni precursor dissolved in oleylamine was injected into a hot solution containing preformed Au–ZnO nanocrystals with specific morphologies. Then Ni prefers to grow on the unoccupied surfaces of Au, thus forming a hybrid hetero-nanostructure which retains the main morphologies of Au–ZnO nanocrystals. The ultraviolet-visible spectra not only show the band gap absorption of ZnO but also exhibit a broadened and weakened surface plasmon resonance (SPR) band of Au. The Ni–Au–ZnO nanocrystals exhibit much higher photocatalytic efficiency than pure ZnO in the degradation of Rhodamine B. Meanwhile, these hybrid nanocrystals are superparamagnetic at room temperature and can be readily recycled by a magnetic field for reuse. The as-prepared ternary Ni–Au–ZnO hybrid nanocrystals possess plasmonic, magnetic and enhanced photocatalytic properties, and thus are expected to find wide applications in the future.

•Amorphous ZnSnO3 double-shell hollow microcubes were synthesized.•D-ZnSnO3 deliver better electrochemical properties than Y-ZnSnO3.•The amorphous feature and double-shell hollow structure improves the performance.Amorphous ZnSnO3 double-shell and yolk-shell hollow microcubes were synthesized by calcination of their corresponding ZnSn(OH)6 precursors pre-prepared through a facile chemical solution method in argon. The as-prepared amorphous ZnSnO3 double-shell hollow microcubes have an average edge length of 1.6 μm. When used as the anode materials, amorphous ZnSnO3 double-shell hollow microcubes (D-ZnSnO3) reveal better electrochemical properties than ZnSnO3 yolk-shell counterparts (Y-ZnSnO3). D-ZnSnO3 anodes can retain a high reversible capacity of 741 mA h g−1 after 50 cycles with a coulombic efficiency of 99% at 100 mA g−1. The amorphous feature and unique box-in-box hollow architecture of D-ZnSnO3 play a key role in their excellent electrochemical properties.

•Well-dispersed ZnO–ZnCo2O4 hybrid hollow microspheres are prepared for the first time.•ZnO–ZnCo2O4 hybrid hollow microspheres exhibit greatly enhanced lithium storage properties.•The unique structural features of hybrid microspheres account for their superior electrochemical properties.ZnO–ZnCo2O4 hybrid hollow microspheres are successfully produced via an annealing process of the pre-fabricated zinc–cobalt citrate hollow microspheres in air. ZnO and ZnCo2O4 have homogeneous distribution within the whole hollow microspheres. The gained hybrid hollow microspheres deliver outstanding lithium storage properties when utilized as the anode material in lithium ion batteries. A high reversible capacity of 1199 mA h g−1 can be retained after 200 cycles. The exceptional electrochemical properties of the hybrid hollow microspheres are ascribed to the synergetic effect between ZnO and ZnCo2O4 nanoparticles, the catalytic effect of Co nanocrystals, the favorable hollow structures together with the nanometer-sized building blocks of hybrid microspheres.

The preparation of noble metal–semiconductor hybrid nanocrystals with controlled morphologies has received intensive interest in recent years. In this study, facile one-pot reactions have been developed for the synthesis of Au–ZnO hybrid nanocrystals with different interesting morphologies, including petal-like and urchin-like nanoflowers, nanomultipods and nanopyramids. In the synthesis strategy, oleylamine-containing solution serves as the reaction medium, and the in situ generated Au seeds play an important role in the subsequently induced growth of ZnO nanocrystals. With the aid of several surfactants, hybrid nanocrystals with different morphologies that have considerable influences on their optical and photocatalytic activities are readily achieved. Through high-resolution transmission electron microscopy measurements, an observed common orientation relationship between ZnO and Au is that ZnO nanocrystals prefer to grow with their polar {001} facets on the {111} facets of Au nanocrystals, and well-defined interfaces are evident. Surface plasmon resonance bands of Au with different positions are observed in the UV-vis spectra, and the UV and visible emissions of ZnO are found to be dramatically reduced. Finally, the as-prepared Au–ZnO nanocrystals exhibit excellent photocatalytic activity for the photodegradation of rhodamine B compared with pure ZnO nanocrystals. The Au–ZnO hybrid nanopyramids show the highest catalytic efficiency, which is correlated with the exposed crystal facets, crystallinity and the formation of hybrid nanostructures. The as-prepared Au–ZnO hybrid nanocrystals are expected to find diverse potential applications in the fields such as photocatalysis, solar energy conversion, sensing and biological detection.

In this article, well-dispersed CeO2–ZnO composite hollow microspheres have been fabricated through a simple chemical reaction followed by annealing treatment. Amorphous zinc–cerium citrate hollow microspheres were first synthesized by dispersing zinc citrate hollow microspheres into cerium nitrate solution and then aging at room temperature for 1 h. By calcining the as-produced zinc–cerium citrate hollow microspheres at 500 °C for 2 h, CeO2–ZnO composite hollow microspheres with homogeneous composition distribution could be harvested for the first time. The resulting CeO2–ZnO composite hollow microspheres exhibit enhanced activity for CO oxidation compared with CeO2 and ZnO, which is due to well-dispersed small CeO2 particles on the surface of ZnO hollow microspheres and strong interaction between CeO2 and ZnO. Moreover, when Au nanoparticles are deposited on the surface of the CeO2–ZnO composite hollow microspheres, the full CO conversion temperature of the as-produced 1.0 wt % Au–CeO2–ZnO composites reduces from 300 to 60 °C in comparison with CeO2–ZnO composites. The significantly improved catalytic activity may be ascribed to the strong synergistic interplay between Au nanoparticles and CeO2–ZnO composites.Keywords: catalytic oxidation; CeO2; composite hollow microspheres; zinc−cerium citrate; ZnO;

Hierarchical ZnO–Ag–C composite porous microspheres are successfully synthesized by calcination of the preproduced zinc–silver citrate porous microspheres in argon. The carbon derives from the in situ carbonization of carboxylic acid groups in zinc–silver citrate during annealing treatment. The average particle size of ZnO–Ag–C composite porous microspheres is approximate 1.5 μm. When adopted as the electrode materials in lithium ion batteries, the obtained composite porous microspheres display high specific capacity, excellent cyclability, and good rate capability. A discharge capacity as high as 729 mA h g–1 can be retained after 200 cycles at 100 mA g–1. The excellent electrochemical properties of ZnO–Ag–C are ascribed to its unique hierarchical porous configuration as well as the modification of silver and carbon.Keywords: carbon; hierarchical porous microspheres; lithium ion batteries; silver; zinc oxide

•ZnO-C yolk-shell microspheres, hollow microspheres and solid microspheres are prepared.•Yolk-shell ZnO-C microspheres possess the best electrochemical properties when used as the anode materials for lithium-ion batteries.•The special yolk-shell structures and extra carbon support account for the enhanced electrochemical properties.Three ZnO-C samples with distinct structures including yolk-shell microspheres, hollow microspheres and solid microspheres are fabricated through a facile chemical solution reaction followed by calcination in argon. When employed as the anode materials for lithium ion batteries, yolk-shell ZnO-C microspheres exhibit the best electrochemical properties than the hollow and solid microspheres. After 150 cycles, yolk-shell ZnO-C microspheres demonstrate a relative high capacity of 520 mA h g−1 at a current density of 100 mA g−1 with a Coulombic efficiency of about 99.3%. The excellent cycling stability and good rate capability of yolk-shell ZnO-C microspheres stem from the synergistic effect of the unique yolk-shell structures and extra carbon support.

•Amorphous ZnSnO3-C hollow microcubes were prepared for the first time.•ZnSnO3-C hollow microcubes exhibit greatly enhanced lithium storage properties.•The reason for the superior electrochemical properties is proposed.Amorphous ZnSnO3-C hollow microcubes have been produced by calcination of the pre-synthesized ZnSn(OH)6 hollow microcubes in argon, followed by the surface decoration of carbon. The calcination temperature plays an important role in the phase and morphology of the obtained products. ZnSnO3-C hollow microcubes have an average edge length of about 1.0 μm with the shell thickness of approximate 145 nm. When adopted as the anode materials for lithium ion batteries, amorphous ZnSnO3-C hollow microcubes manifest greatly enhanced electrochemical properties compared to amorphous ZnSnO3 hollow and solid counterparts. After 50th cycles, a high reversible capacity of 703 mA h g−1 can be obtained for amorphous ZnSnO3-C hollow microcubes at the current density of 100 mA g−1. The superior lithium storage properties of ZnSnO3-C are due to its unique hollow structure with large specific surface area, the modification of carbon and the amorphous characteristic.

An enhanced anomalous Hall effect is observed in heterogeneous uniform Fe cluster assembled films with different film thicknesses (ta = 160–1200 nm) fabricated by a plasma-gas-condensation method. The anomalous Hall coefficient (Rs) at ta = 1200 nm reaches its maximum of 2.4 × 10−8 Ω cm G−1 at 300 K, which is almost four orders of magnitude larger than bulk Fe. The saturated Hall resistivity (ρAxy) first increases and then decreases with the increase of temperature accompanied by a sign change from positive to negative. Analysis of the results revealed that ρAxy decreases with increasing longitudinal resistivity (ρxx) on a double-logarithmic scale and obeys a new scaling relation of log(ρAxy/ρxx) = a0 + b0 logρxx.

•The [Fe80Ni20–O/NiZn–ferrite]n multilayer thin films were prepared by magnetron sputtering.•The substrate temperature affect the high-frequency soft magnetic properties of the films.•The multilayer thin films have good high-frequency magnetic properties.In this research, a series of [Fe80Ni20–O/NiZn–ferrite]n multilayer thin films were prepared by magnetron sputtering at different substrate temperatures. The influences of NiZn–ferrite interlayer and substrate temperature on high-frequency soft magnetic properties of [Fe80Ni20–O/NiZn–ferrite]n multilayer thin films were investigated. It was found that the saturation magnetization was highly dependent on the substrate temperature during the sputtering procedure. By increasing the substrate temperature from room temperature to 300 °C, the saturation magnetization increased from 7.34 kG to maximum of 9.26 kG at 150 °C, and then decreased to 6.53 kG at 300 °C. The adjustment of substrate temperature is essential to obtain the low coercivity, high permeability and controllable in-plane uniaxial magnetic anisotropy field of the multilayer thin films.

•The first report on the HER properties of magnetic metal phosphide nanorods.•Co2P on Ti electrode exhibits an overpotential of 160 mV at 20 mA/cm2.•Co2P on glassy carbon electrode has the lowest Tafel slope of 53 mV/decade.•Magnetic metal phosphide nanocrystals are promising as a lower cost catalyst for HER.Efficient and economical hydrogen evolution reaction (HER) from water splitting holds a bright prospect for clean energy. Replacement of expensive Pt-based catalysts with earth-abundant catalysts is beneficial for this field. In this study, nanoscale magnetic metal phosphides including Co2P, Co1.33Ni0.67P and Ni2P nanorods are synthesized by a facile solution method. Their HER activities and stabilities on glassy carbon and Ti electrodes are investigated. The Co2P nanorods deposited on glassy carbon electrodes are found to show higher activity and better reversibility than the Co1.33Ni0.67P and Ni2P counterparts. Nevertheless, the Co1.33Ni0.67P and Ni2P samples on Ti electrodes gain a significant activity promotion after annealing in H2/Ar atmosphere. Investigation of the Tafel curves shows that the Co2P nanorods on glassy carbon have the lowest Tafel slope while their exchange current density on Ti electrode exhibits a high value which is comparable to that of Pt electrode. Furthermore, the cyclic voltammetric tests show that the reversibility of annealed Co2P on Ti electrode is the best, which emphasizes the superiority of Co species in catalyzing HER reaction. Finally, the three magnetic metal phosphide catalysts are found to exhibit good stabilities in acidic conditions according to the galvanostatic testing results.

Germanium is a promising high-capacity anode material for lithium ion batteries. But as a huge volume variation always occurs during the charge/discharge process, it usually exhibits poor cycling stability. Herein, a low-cost Ge precursor was used for the preparation of Ge@C core–shell composited NWs by a facile and “green” synthetic route. The Ge@C nanocomposites, as anode materials for lithium-ion batteries, exhibited a high initial discharge capacity of 1648 mA h g−1 and superior rate capability. In particular, Ge@C nanocomposite electrodes maintained a reversible capacity of 1086 mA h g−1 after repeated cycling at a current density of 0.5 C (600 mA g−1) over 200 cycles.

•A facile solution route to monodisperse Ni nanoparticles with tunable sizes.•3D Ni nanoparticle superlattices are formed on different substrates.•A dominant large-scale hcp symmetry is observed on carbon film substrate.•Typical structural parameters are obtained on the 3D nanoparticle superlattices.•The demonstrated method gives a convenient access to study collective properties.Monodisperse Ni nanoparticles with sizes varying from 4.8 to 11.3 nm are prepared via a one-pot reaction that involves the reduction of nickel(II) acetylacetonate in oleylamine in the presence of trioctylphosphine and 1,2-hexadecanediol. Reaction parameters such as temperature and the concentration of capping agent and metal precursor are critical for the adjustment of particle size. The decrease of crystallinity is observed for the samples with smaller particle sizes, which significantly affects the magnetic properties. Three-dimensional (3D) superlattices that are composed of Ni nanoparticles with different sizes are obtained on different substrates by a facile self-assembly process, and are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and small-angle X-ray diffraction (SAXRD). The Ni nanoparticle superlattices formed on carbon-coated TEM copper grids exhibit a dominant hexagonal close-packed (hcp) symmetry, although local fcc packing is also occasionally observed. The formation of 3D nanoparticle superlattice structures on Si substrates is confirmed from the SAXRD measurements. The method revealed in this study for the preparation of 3D superlattices composed of Ni nanoparticles with tunable sizes offers the potential to explore their interesting collective properties for multiple applications.

Synthesis of stable and monodisperse Cu nanocrystals of controlled morphology has been a long-standing challenge. In this Article, we report a facile disproportionation reaction approach for the synthesis of such nanocrystals in organic solvents. Either spherical or cubic shapes can be produced, depending on conditions. The typical Cu nanospheres are single crystals with a size of 23.4 ± 1.5 nm, and can self-assemble into three-dimensional (3D) nanocrystal superlattices with a large scale. By manipulating the chemical additives, monodisperse Cu nanocubes with tailorable sizes have also been obtained. The probable formation mechanism of these Cu nanocrystals is discussed. The narrow size distribution results in strong surface plasmon resonance (SPR) peaks even though the resonance is located in the interband transition region. Double SPR peaks are observed in the extinction spectra for the Cu nanocubes with relative large sizes. Theoretical simulation of the extinction spectra indicates that the SPR band located at longer wavelengths is caused by assembly of Cu nanocubes into more complex structures. The synthesis procedure that we report here is expected to foster systematic investigations on the physical properties and self-assembly of Cu nanocrystals with shape and size singularity for their potential applications in photonic and nanoelectronic devices.

A highly shape selective synthesis of Cu and Cu@Cu–Ni nanocubes and nanowires has been developed by modulating the coordination chemistry of transition metal ions with a trioctylphosphine (TOP)–Cl− ligand pair in oleylamine under mild organic solvent conditions. The as-prepared nanocubes have a face-centered cubic (fcc) phase and are covered by six {100} facets, whereas the as-prepared nanowires have a multi-twinned structure and grow along the [110] direction. Both the Ni2+ and Cl− ions, along with TOP, play vital roles in determining the final morphology of the as-prepared nanocrystals (NCs). TOP can be used to selectively generate single-crystal seeds at the initial stage, which then grow into nanocubes in the presence of Cl− ions, while the absence of TOP leads to the formation of multi-twined crystal seeds that finally develop into nanowires. Moreover, Ni can be incorporated to form a Cu–Ni alloy shell over a Cu core at higher temperatures in a one-pot process, which makes diamagnetic Cu NCs magnetically responsive and has a significant influence on their optical properties.

A facile nonaqueous injection method has been developed for the construction of one-dimensional nanostructure consisting of a magnetic alloy (Ni–Cu) core and a plasmonic alloy (Au–Cu) shell. The obtained Ni–Cu@Au–Cu nanowires exhibit tunable optical and magnetic properties.

A novel and facile approach was developed for the fabrication of amorphous double-shelled zinc–cobalt citrate hollow microspheres and crystalline double-shelled ZnCo2O4 hollow microspheres. In this approach, amorphous double-shelled zinc–cobalt citrate hollow microspheres were prepared through a simple route and with an aging process at 70 °C. The combining inward and outward Ostwald ripening processes are adopted to account for the formation of these double-shelled architectures. The double-shelled ZnCo2O4 hollow microspheres can be prepared via the perfect morphology inheritance of the double-shelled zinc–cobalt citrate hollow microspheres, by calcination at 500 °C for 2 h. The resultant double-shelled ZnCo2O4 hollow microspheres manifest a large reversible capacity, superior cycling stability, and good rate capability.Keywords: anode; double-shelled hollow microspheres; Ostwald ripening; zinc−cobalt citrate; ZnCo2O4;

A novel hierarchical network-like Co3O4 are successfully synthesized by hydrothermal method combined with subsequent annealing treatment in air. The evolution process of network-like Co(CO3)0.5(OH)·0.11H2O precursor are characterized by XRD, SEM and FT-IR methods. The as-prepared network-like Co3O4 are tested as an anode material in lithium-ion batteries. The influences of the Co3O4 morphology on the electrochemical performances are investigated. In the specific capability test, the first discharge capacity of 2008 mAh g−1 is recorded at current density of 100 mA g−1. The excellent electrochemical properties of the Co3O4 electrodes can be attributed to high specific surface area which provides more active area that can react with Li+ ions, leading to outstanding specific capacitance. And the results indicated that the polypyrrole (PPy) as a conductive macromolecule coating on the Co3O4 surface can improve performance of the LIBs obviously.

A magnetically separable core-shell Ag@Ni nanocatalyst was prepared by a simple one-pot synthetic route using oleylamine both as solvent and reducing agent and triphenylphosphine as surfactant. The synthesized nanoparticles were characterized by several techniques such as X-ray diffraction pattern (XRD), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern, and energy dispersive X-ray spectroscopy (EDS). The core-shell Ag@Ni nanocatalyst was found to have very excellent activity for the transfer hydrogenation reactions of aromatic nitro and carbonyl compounds under mild conditions using isopropyl alcohol as hydrogen donor. Excellent chemoselectivity and regioselectivity for the nitro group reduction was demonstrated.

Thin film materials with excellent high-frequency, magnetic and electrical properties are in great demand in modern electromagnetic devices operating in GHz range. In this letter, we fabricated [Fe80Ni20–O/SiO2]n multilayer thin films with different SiO2 interlayer thicknesses (t=0.5–4 nm) and fixed Fe80Ni20–O layer thickness by controlling the sputtering time at room temperature. In these films, the in-plane uniaxial magnetic anisotropy fields can be adjusted in a broad range (from 26 to 107 Oe) by just changing the thickness of each SiO2 interlayer without applying any inducing field. Excellent high-frequency performances in GHz range have been observed in the typical sample.Highlights► [Fe80Ni20–O/SiO2]n multilayer thin films were fabricated by magnetron sputtering. ► In-plane magnetic anisotropy can be adjusted only by the thickness of SiO2 layer. ► Excellent high-frequency characteristics in a broad GHz range can be obtained. ► Promote the application of the multilayer thin films in the GHz range.

•First synthesis of Ni–Cu@Au–Cu alloy core–shell nanoparticles via a solution method.•Surface plasmon resonance absorption band at red light region was observed.•Room-temperature ferromagnetic properties was identified.•Alloy core–shell structure offers tunable optical and magnetic properties.We report a solution method for the preparation of alloy core–shell nanoparticles which consist of Ni–Cu cores and Au–Cu shells. This method involves an injection-quenching step in which Au precursor is injected in and reduced to form alloy shells on pre-formed Ni–Cu cores. The as-prepared Ni–Cu@Au–Cu nanoparticles possess a spherical morphology, and have a typical size of ∼35 nm and shell thickness of 6–9 nm. The formed core–shell structure has been verified by high-resolution transmission electron microscopy and high-angle annular dark-field imaging along with the analyses of energy-dispersive X-ray spectroscopy. Broadened surface plasmon resonance (SPR) absorption band centering at red light region has been observed. Magnetic measurements reveal room-temperature ferromagnetic properties for the as-prepared Ni–Cu@Au–Cu nanoparticles. The formation of alloy core–shell structure offers tunable optical and magnetic properties for their multiple applications.Graphical abstract

A facile one-pot route has been developed for the synthesis of hexagonal and triangular Ni–Cu alloy nanoplates. The synthesis was conducted using nickel(II) acetylacetonate and copper(II) chloride dihydrate as metal precursors, trioctylphosphine as a capping agent, and oleylamine as a solvent and reducing agent. Structural analyses from X-ray diffraction and transmission electron microscopy indicate that the as-synthesized nanoplates have an fcc crystalline structure and their side faces are bound by a mixture of {100} and {111} facets, while their top and bottom faces are bound by {111} facets. The oxidative etching effect of Cu(II) on Ni(0) in the presence of Cl ions plays an important role in the generation of the anisotropic nanoplates. The results of magnetic measurements revealed differences between the hexagonal and triangular nanoplates in their ability to undergo the transition from the ferromagnetic to the superparamagnetic state with increasing temperature. The magnetic properties of the as-synthesized Ni–Cu alloy nanoplates can also be tuned by adjusting the Ni content which correlates closely with reaction temperature. Excellent catalytic properties for the catalytic reduction of methylene blue by NaBH4 in aqueous solution were observed for the as-synthesized nanoplates.

Although the combination of magnetic and noble metals in core-shell nanoparticles is very useful in many applications, the preparation of magnetic-noble bimetallic core-shell nanoparticles with uniform shells remains a great challenge due to large mismatch of crystal lattices between magnetic and noble metals. Herein we present non-aqueous methods for combing Au and Ni in nanoscale to form a core-shell structure. Ni@Au nanoparticles were prepared via an injection-quenching process in which Au precursors decomposed and formed closed shells on pre-formed Ni seeds synthesized in oleylamine, whereas Au@Ni nanoparticles were obtained in a one-step reaction involving a seed-catalyzed mechanism. The formed core-shell structure was confirmed by high-angle annular dark-field imaging along with the analyses of energy-dispersive X-ray spectroscopy and high-resolution transmission electron microscopy. UV-Visible absorption spectroscopy and superconducting quantum interference device magnetometer were used to characterize the optical and magnetic properties of the as-prepared bimetallic core-shell nanoparticles. Through the adjustment of growth conditions, Ni@Au and Au@Ni nanoparticles with different core or shell dimensions and morphologies were obtained, which offers an important means to tailor their optical and magnetic properties for multiple practical applications.

In this letter, we propose a method to fabricate Fe80Ni20–O film with improved static and high-frequency, magnetic and electrical properties. Fe80Ni20–O alloy films were prepared by direct current magnetron sputtering at room temperature. The results show that the in-plane uniaxial magnetic anisotropy fields can be adjusted in a broad range by solely adding a very low dose of oxygen into Fe80Ni20 alloy films without applying any inducing field on substrates during deposition. By increasing the oxygen flow ratio from 0.75% to 3%, Fe80Ni20–O alloy films could be achieved with an adjustable ferromagnetic resonance frequency fr (from 2.2 to 5.9 GHz), a large saturation magnetization 4πMs (from 16.7 to 15.2 kG), and a high resistivity ρ (from 56.7 to 108 μΩ cm).Highlights► Improve the high-frequency magnetic characteristics of Fe80Ni20–O film. ► In-plane uniaxial magnetic anisotropy fields can be adjusted only by adding oxygen. ► Adjustable ferromagnetic resonance frequency in a broad GHz range can be obtained. ► Promote the application of soft magnetic films as the materials for high-frequency.

Al-rich AlxCr1−xN coatings have been deposited by reactive magnetron co-sputtering using a direct current (DC) power source to Al and a radio frequency (RF) power source to Cr target. The crystal structure, chemical composition, surface morphology, thickness and hardness of the AlxCr1−xN coatings which were prepared at various N2 flow rates and working pressures have been systemically investigated. The results show a strong effect of N2 flow rates and working pressures on the phase composition and microstructure as well as the Al content in AlxCr1−xN coatings. The present results also show Al contents play an important role in the hardness of the AlxCr1−xN coatings, which demonstrates the highest hardness for Al contents close to the maximum solubility in cubic AlxCr1−xN.

Magnetically soft Fe-Co-based nanocrystalline alloy films were produced by two preparation methods: One using a new energetic cluster deposition technique and another using a conventional magnetron sputtering technique. Their structural, static magnetic properties and high-frequency magnetic characteristics were investigated. In the energetic cluster deposition method, by applying a high-bias voltage to a substrate, positively charged clusters in a cluster beam were accelerated electrically and deposited onto a negatively biased substrate together with neutral clusters from the same cluster source, to form a high-density Fe-Co alloy cluster-assembled film with good high-frequency magnetic characteristics. In the conventional magnetron sputtering method, only by rotating substrate holder and without applying a static inducing magnetic field on the substrates, we produced Fe-Co-based nanocrystalline alloy films with a remarkable in-plane uniaxial magnetic anisotropy and a good soft magnetic property. The obtained Fe-Co-O, Fe-Co-Ti-N, and Fe-Co-Cr-N films all revealed a high real permeability exceeding 500 at a frequency up to 1.2 GHz. This makes Fe-Co-based nanocrystalline alloy films potential candidates as soft magnetic thin film materials for the high-frequency applications.

Previous preparation of iron phosphide nanowires usually employed toxic and unstable iron carbonyl compounds as precursor. In this study, we demonstrate that iron phosphide nanowires can be synthesized via a facile nonaqueous chemical route that utilizes a commonly available iron precursor, iron (III) acetylacetonate. In the synthesis, trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO) have been used as surfactants, and oleylamine has been used as solvent. The crystalline structure and morphology of the as-synthesized products were characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The obtained iron phosphide nanowires have a typical width of ~16 nm and a length of several hundred nanometers. Structural and compositional characterization reveals a hexagonal Fe2P crystalline phase. The morphology of as-synthesized products is greatly influenced by the ratio of TOP/TOPO. The presence of TOPO has been found to be essential for the growth of high-quality iron phosphide nanowires. Magnetic measurements reveal ferromagnetic characteristics, and hysteresis behaviors below the blocking temperature have been observed.

Fe1−xCox nanowires in self-assembled arrays with varying compositions were produced by the template-assisted pulsed electrochemical deposition method. The structural and magnetic properties of the arrays were investigated using several experimental techniques. TEM analyses indicated that the nanowires were regular, uniform, 8 μm in length and 50 nm in diameter. The results of X-ray diffraction indicated that the body-centered-cubic (bcc) (α), face-centered-cubic (fcc) (γ), and hexagonal-close-packed (hcp) (ɛ) Fe–Co phases appeared in different compositions. Magnetic measurements showed that the coercivity and squareness of the hysteresis loops of the Fe1−xCox changed with their compositions, which may be attributable to shape anisotropy. The room temperature 57Fe Mössbauer spectra of the arrays of the Fe1−xCox nanowires revealed strong shape anisotropy.

The effect of oxygen-doping has been studied on the magnetic properties of Fe thin films produced at room temperature by a helicon-plasma-enhanced RF magnetron sputter-deposition. A reduction in magnetic coercivity due to grain refinement was achieved using very low dose of oxygen, which did not lead to the formation of crystalline Fe oxides with the low saturation magnetization. Moreover, it was demonstrated that oxygen-doping also enhances the in-plane uniaxial magnetic anisotropy of Fe films and thus can be applied beneficially to increase high-frequency permeability which is needed in microwave applications.

Size-monodispersed Fe70Co30 alloy clusters were obtained by a plasma-gas-condensation (PGC)-type cluster deposition method. The structural and magnetic characteristics of Fe70Co30 alloy cluster-assembled films were systematically studied. The as-obtained Fe70Co30 clusters have a body-centered-cubic (bcc) α-(Fe,Co) structure and their average sizes can be adjusted from 8 to 14 nm. Based upon the temperature dependence of magnetic coercivity, we estimated the effective magnetic anisotropy constant, Keff, and magnetic exchange length, Lex, as a function of initial mean cluster diameter, d, in the Fe70Co30 cluster-assembled films which were formed by soft landing of the clusters and have a low cluster-packing fraction of about 30%. The estimated Keff and Lex values depend strongly on the d values of the cluster-assembled films: Keff decreases while Lex increases with decreasing d of the Fe70Co30 clusters. For the Fe70Co30 cluster-assembled films with d = 14.3 nm, the Lex value is close to the initial mean cluster size, whereas for the films with d = 9.7 nm the Lex value is about two times of the initial mean cluster size.

SnS films were prepared by electrodeposition onto the indium–tin-oxide (ITO)-coated glass successfully. The X-ray diffraction (XRD) pattern shows the orthorhombic structure and average grain size of the films is about 10 nm. The SnS films reflect a needle-like crystal structure with a tightly bonded together and these crystallites are also oriented randomly and exhibit nearly equal sizes. The energy dispersive X-ray (EDX) analysis indicates that the atomic ratio of Sn to S is 50.6:49.4. The optical band gap of the films is evaluated using transmittance and reflectance data. From the optical measurement, the direct band gap of the thin film is estimated to be 1.34 eV.

SnS thin films were deposited on ITO substrates from SnCl2 and Na2S2O3 aqueous solution by pulse electro-deposition method, and the as-prepared SnS thin films were annealed at different temperatures in air for 1 h. The XRD pattern shows that the film decomposed and was oxidized completely at 250 °C. The surface morphology and grain size changed with the annealing temperature. The increase of the annealing temperature improved the crystallinity of the deposit and made the scope of absorbed light wavelength larger. Also, the direct energy gap Eg changed with the annealing temperature. The SnS thin films annealed at 100 °C have good crystallinity and show strong blue-UV emission, being promising for applications in optical devices. And the band-to-band emission peak (∼920 nm) of the SnS thin film indicated the energy gap is 1.37 eV.

Fe–Co–Cr and Fe–Co–Cr–N thin films were fabricated by magnetron co-sputtering at room temperature, and their structural, electrical and magnetic properties were examined by various analytic techniques. It was observed that with the increase of Cr-target power, for Fe–Co–Cr thin films the resistivity increased and surface morphology was changed. As the nitrogen gas flow ratio increased, for Fe–Co–Cr–N thin films the grain size decreased and the resistivity monotonically increased. Fe–Co–Cr thin films exhibited the best soft-magnetic properties with a relatively large saturation magnetization (Ms) of 1.77 Wb/m2 and a small coercivity (Hc) of 748 A/m at a Cr-target power of 80 W, whereas Fe–Co–Cr–N thin films had the best soft-magnetic properties with a high saturation magnetization (Ms) of 1.64 Wb/m2 and a minimum coercivity (Hc) of 279 Wb/m2 at a nitrogen gas flow ratio of 20%. The grain refinement mechanism of chromium and nitrogen in the FeCo-based films was also discussed.

The ferromagnetic transparent conductive (FTC) films were fabricated by introducing a magnetic Fe thin film into aluminum-doped zinc oxide (AZO) matrix using magnetron sputtering apparatus. The room temperature (RT) ferromagnetism was observed in all samples prepared at different substrate temperatures (Ts = RT, 200 and 300 °C) and an anomalous magnetization characteristic was observed. There were turning points in the hysteresis loops. Evolution of optical and electrical properties of the FTC AZO/Fe/AZO composite films as a function of substrate temperature has been analyzed.

Fe–Ni nanoparticles have been synthesized via a nonaqueous solution-phase approach using thermal decomposition of Ni(II) acetylacetonate and Fe(III) acetylacetonate in oleylamine without further reducing agents. The analyses of powder X-ray diffraction and transmission electron microscopy show that the as-synthesized Fe–Ni nanoparticles possess a face-centered cubic (fcc) crystalline structure and exhibit a polydispersed characteristic. The particle morphology and size distribution can be further controlled by introducing surfactants in the reaction system, and the final chemical composition also can be tuned to some extent by varying the initial molar ratios of metal precursors. Room temperature magnetic measurements reveal a ferromagnetic characteristic for the as-synthesized nanoparticles. An increased saturation magnetization has been observed with increasing Fe contents.

The SnS nanowire arrays have been successfully synthesized by the template-assisted pulsed electrochemical deposition in the porous anodized aluminum oxide template. The investigation results showed that the as-synthesized nanowires are single crystalline structures and they have a highly preferential orientation. The ordered SnS nanowire arrays are uniform with a diameter of 50 nm and a length up to several tens of micrometers. The synthesized SnS nanowires exhibit strong absorption in visible and near-infrared spectral region and the direct energy gapEgof SnS nanowires is 1.59 eV.

The effects of the introduction of oxygen were studied on the Fe62Co32Cr6–O alloy films synthesized by magnetron co-sputtering. The as-deposited films exhibited a high saturation magnetization and a suitable in-plane uniaxial anisotropy field at an optimized condition of an oxygen gas flow ratio of 1.3%. Also, a high real permeability of ∼200 at frequency up to 3.3 GHz was obtained from the microwave permeability measurement at the optimized condition above. The combination of high saturation magnetization, adjustable in-plane uniaxial magnetic anisotropy field, and high resistivity makes the Fe62Co32Cr6–O films become a promising candidate for the high-frequency applications.

In this work, we report the preparation of bimetallic core-shell nanoparticles (NPs) using a simple solution synthetic route. A typical example is the Ag@Ni NPs that are synthesized using oleylamine as solvent and reducing agent. The as-obtained Ag@Ni NPs exhibit a spherical morphology and a highly narrow size distribution. Excellent catalytic properties for the H2 generation from dehydrogenation of sodium borohydride in aqueous solutions are observed. Similar synthetic strategies have also been developed for the preparation of other bimetallic core-shell NPs, such as Ag@Co and Cu@Ni NPs. These bimetallic core-shell NPs are promising candidates for novel optical and magnetic materials as well as high-performance catalysts.

In this work, we attempted to construct a ferromagnetic transparent conducting film through multilayer approach. The ferromagnetic transparent conducting ZnO:Al/Fe65Co35/ZnO:Al tri-layer structure films were fabricated by inserting a middle magnetic Fe65Co35 thin layer into ZnO:Al matrix using multi-target magnetron sputtering apparatus at the substrate temperature of 300 °C. The ferromagnetism was observed by vibrating sample magnetometer (VSM) at room temperature, and the in-plane hysteresis loops revealed that the magnetic properties strongly depended on the Fe65Co35 layer thickness. The inserted middle Fe65Co35 thin layer played an important role in providing the ferromagnetism and decreasing the resistivity of the multifunctional films.

•A facile solution route to monodisperse iron oxide nanocrystals with tunable shapes.•The magnetic properties of iron oxide nanocrystals are greatly affected by their shapes.•The microwave absorption performance of nanospheres, nanocubes and nanoplates is compared.•Triangular Fe3O4 nanoplates exhibit superior microwave absorption properties.Synthesis of uniform magnetic nanocrystals with tunable shape is valuable to investigate the microwave absorption properties that depend closely on the shape and size. In this study, we utilize an efficient method to synthesize nano-sized iron oxide nanocrystals with different shapes through thermal decomposition of Fe(acac)3 in oleylamine. While the spherical Fe3O4 nanocrystals display a typical superparamagnetic behavior at room temperature, the triangular nanoplates exhibit a blocking behavior at an unexpected high temperature. The antiferromagnetic-ferrimagnetic core-shell structure of FeO@Fe3O4 nanocubes presents exchange bias behavior. We also investigate the high frequency properties of all samples by a network analyzer. Compared to spherical and cubic shapes, the triangular Fe3O4 nanoplates exhibit significantly enhanced microwave absorption performance in terms of strong reflection loss and wide bandwidth. Moreover, the triangular Fe3O4 nanoplates have obvious dielectric and magnetic resonance behaviors responding to the microwave at the frequency range of 2–18 GHz. The dielectric and magnetic resonance behaviors may be derived from the interface polarization and exchange resonance. The minimum reflection loss of triangular Fe3O4 nanoplates reaches −32.1 dB at 11.7 GHz and the bandwidth less than −10 dB is from 10.6 to 13.3 GHz at a thickness of 2.5 mm.

We report on the synthesis of single-crystalline Ni2P nanowires via a solution-phase approach using nickel (II) acetylacetonate as a metal precursor and trioctylphosphine as a phosphorus source. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the crystalline structure, morphology and composition of the as-synthesized nanowires. The results show that the as-synthesized nanowires have a uniform width of ca. 6 nm, and a length that can vary from tens of nanometers to several hundred nanometers. These nanowires possess a hexagonal crystalline phase, and predominantly grow along the c-axis. The formation of one-dimensional nanostructures has a close relationship with the concentration of metal precursor and surfactants, and the synthetic methodologies.

•Co2P-Co hollow nanospheres with graphene sheets decoration are prepared through one-pot solution approach.•Co2P-Co/graphene nanocomposites reveal greatly enhanced lithium storage performances than Co2P-Co counterparts.•The superb electrochemical performances derive from dual modification of graphene sheets and metal Co as well as their hollow configuration.The fabrication of Co2P-Co (Co-P composites) hollow nanospheres with graphene sheets decoration through one-pot solution approach is demonstrated and their potential as the anode materials for lithium ion batteries is assessed. A large specific capacity of 929 mA h g−1 can be retained for Co-P/graphene nanocomposites at 100 mA g−1 after 200 cycles. When cycled at a large current density of 2.0C, the Co-P/graphene nanocomposites deliver a decent reversible capacity of 567 mA h g−1, which is much higher than the theoretical capacity of traditional graphite anode (372 mA h g−1). The obviously enhanced lithium storage properties of Co-P/graphene nanocomposites are put down to the dual modification of graphene sheets and metal Co as well as their hollow structures.

Although the combination of magnetic and noble metals in core-shell nanoparticles is very useful in many applications, the preparation of magnetic-noble bimetallic core-shell nanoparticles with uniform shells remains a great challenge due to large mismatch of crystal lattices between magnetic and noble metals. Herein we present non-aqueous methods for combing Au and Ni in nanoscale to form a core-shell structure. Ni@Au nanoparticles were prepared via an injection-quenching process in which Au precursors decomposed and formed closed shells on pre-formed Ni seeds synthesized in oleylamine, whereas Au@Ni nanoparticles were obtained in a one-step reaction involving a seed-catalyzed mechanism. The formed core-shell structure was confirmed by high-angle annular dark-field imaging along with the analyses of energy-dispersive X-ray spectroscopy and high-resolution transmission electron microscopy. UV-Visible absorption spectroscopy and superconducting quantum interference device magnetometer were used to characterize the optical and magnetic properties of the as-prepared bimetallic core-shell nanoparticles. Through the adjustment of growth conditions, Ni@Au and Au@Ni nanoparticles with different core or shell dimensions and morphologies were obtained, which offers an important means to tailor their optical and magnetic properties for multiple practical applications.

Cu seeds were used to direct the epitaxial growth of Ni shell to form Cu–Ni core–shell cubes, tetrahexahedrons and nanowires. The controllable epitaxial growth of Ni shells on Cu cores provided selectively exposed surfaces and morphologies as well as tunable magnetic properties.

A facile nonaqueous injection method has been developed for the construction of one-dimensional nanostructure consisting of a magnetic alloy (Ni–Cu) core and a plasmonic alloy (Au–Cu) shell. The obtained Ni–Cu@Au–Cu nanowires exhibit tunable optical and magnetic properties.

An enhanced anomalous Hall effect is observed in heterogeneous uniform Fe cluster assembled films with different film thicknesses (ta = 160–1200 nm) fabricated by a plasma-gas-condensation method. The anomalous Hall coefficient (Rs) at ta = 1200 nm reaches its maximum of 2.4 × 10−8 Ω cm G−1 at 300 K, which is almost four orders of magnitude larger than bulk Fe. The saturated Hall resistivity (ρAxy) first increases and then decreases with the increase of temperature accompanied by a sign change from positive to negative. Analysis of the results revealed that ρAxy decreases with increasing longitudinal resistivity (ρxx) on a double-logarithmic scale and obeys a new scaling relation of log(ρAxy/ρxx) = a0 + b0 logρxx.