Synthesis of ZnO-ZnCo2O4 hybrid hollow microspheres with excellent lithium storage properties

通讯作者地址: Peng, DLZnO-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

Synthesis of ZnO-ZnCo2O4 hybrid hollow microspheres with excellent lithium storage properties

通讯作者地址: Peng, DLZnO-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

Au-ZnO hybrid nanoflowers, nanomultipods and nanopyramids: one-pot reaction synthesis and photocatalytic properties

Fundamental Research Funds for the Central Universities of China [2011121003]; National Basic Research Program of China [2012CB933103]; National Outstanding Youth Science Foundation of China [50825101]; National Natural Science Foundation of China [51171157, 51171158]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

Shape-related optical and catalytic properties of wurtzite-type CoO nanoplates and nanorods

National Basic Research Program of China [2012CB933103]; National Outstanding Youth Science Foundation of China [50825101]; National Natural Science Foundation of China [51171157, 51171158]In this paper, we report the anisotropic optical and catalytic properties of wurtzite-type hexagonal CoO (h-CoO) nanocrystals, an unusual nanosized indirect semiconductor material. h-CoO nanoplates and nanorods with a divided morphology have been synthesized via facile solution methods. The employment of flash-heating and surfactant tri-n-octylphosphine favors the formation of plate-like morphology, whereas the utilization of cobalt stearate as a precursor is critical for the synthesis of nanorods. Structural analyses indicate that the basal plane of the nanoplates is (001) face and the growth direction of the nanorods is along the c axis. Moreover, the UV-vis absorption spectra, the corresponding energy gap and the catalytic properties are found to vary with the crystal shape and the dimensions of the as-prepared h-CoO nanocrystals. Furthermore, remarkable catalytic activities for H-2 generation from the hydrolysis of alkaline NaBH4 solutions have been observed for the as-prepared h-CoO nanocrystals. The calculated Arrhenius activation energies show a decreasing trend with increasing extension degree along the direction, which is in agreement with the variation of the charge-transfer energy gap. Finally the maximum hydrogen generation rate of the h-CoO nanoplates exceeds most of the reported values of transition metal or noble metal containing catalysts performing in the same reaction system, which makes them a low-cost alternative to commonly used noble metal catalysts in H-2 generation from the hydrolysis of borohydrides, and might find potential applications in the field of green energy

A facile approach to fabrication of well-dispersed NiO-ZnO composite hollow microspheres

A novel, facile and template-free approach was developed for the fabrication of amorphous zinc-nickel citrate hollow microspheres and crystalline well-dispersed NiO-ZnO composite hollow microspheres. In this approach, amorphous zinc-nickel citrate hollow microspheres were prepared through a simple chemical reaction and with room temperature ageing at nickel nitrate solution. The zinc-nickel citrate hollow microspheres have an average size of about 1.4 μm. The average thickness of the shell is about 300 nm. The content of Ni in the zinc-nickel citrate can be simply adjusted by changing the ageing time. The well-dispersed NiO-ZnO composite hollow microspheres can be prepared via the perfect morphology inheritance of the zinc-nickel citrate hollow microspheres, by calcination at 500 °C for 2 h. The optical absorption of the samples can extend into the visible region after the loading of NiO. The NiO-ZnO composite hollow microspheres with the high content of NiO exhibit the highest photocatalytic activity for the degradation of different organic dyes including Rhodamine-B, methylene blue and methyl orange under UV irradiation, which might be ascribed to their highest separation efficiency of photogenerated electron-hole pairs. In addition, these NiO-ZnO composite photocatalysts can be used repeatedly without a significant decrease of the photocatalytic activity under UV irradiation. ? 2013 The Royal Society of Chemistry

Injection synthesis of Ni-Cu@Au-Cu nanowires with tunable magnetic and plasmonic properties

National Basic Research Program of China [2012CB933103]; National Outstanding Youth Science Foundation of China [50825101]; National Natural Science Foundation of China [51171157, 51171158]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

Preparation of monodisperse Ni nanoparticles and their assembly into 3D nanoparticle superlattices

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. ? 2014 Elsevier B.V. All rights reserved

Solution preparation of alloy core-shell nanoparticles: The case of Ni-Cu@Au-Cu nanoparticles

National Basic Research Program of China [2012CB933103]; National Outstanding Youth Science Foundation of China [50825101]; National Natural Science Foundation of China [51171157, 51171158]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 similar to 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. (C) 2013 Elsevier B.V. All rights reserved

Comparative Proteomic Analysis of the Hepatic Response to Heat Stress in Muscovy and Pekin Ducks: Insight into Thermal Tolerance Related to Energy Metabolism

<div><p>The Pekin duck, bred from the mallard (<i>Anas platyrhynchos</i>) in china, is one of the most famous meat duck species in the world. However, it is more sensitive to heat stress than Muscovy duck, which is believed to have originated in South America. With temperature raising, mortality, laying performance, and meat quality of the Pekin duck are severely affected. This study aims to uncover the temperature-dependent proteins of two duck species using comparative proteomic approach. Duck was cultured under 39°C ± 0.5°C for 1 h, and then immediately returned to 20°C for a 3 h recovery period, the liver proteins were extracted and electrophoresed in two-dimensional mode. After analysis of gel images, 61 differentially expressed proteins were detected, 54 were clearly identified by MALDI TOF/TOF MS. Of the 54 differentially expressed protein spots identified, 7 were found in both species, whereas 47 were species specific (25 in Muscovy duck and 22 in Pekin duck). As is well known, chaperone proteins, such as heat shock protein (HSP) 70 and HSP10, were abundantly up-regulated in both species in response to heat stress. However, we also found that several proteins, such as α-enolase, and <i>S</i>-adenosylmethionine synthetase, showed different expression patterns in the 2 duck species. The enriched biological processes were grouped into 3 main categories according to gene ontology analysis: cell death and apoptosis (20.93%), amino acid metabolism (13.95%) and oxidation reduction (20.93%). The mRNA levels of several differentially expressed protein were investigated by real-time RT-PCR. To our knowledge, this study is the first to provide insights into the differential expression of proteins following heat stress in ducks and enables better understanding of possible heat stress response mechanisms in animals.</p> </div

2-DE patterns of proteins extracted from Muscovy (A) and Pekin ducks (B).

<p>The experiment was repeated 3 times, and 54 differentially expressed proteins showing significant spot intensity changes under heat stress and recovery are marked in A and B. The proteins to which these 54 differentially expressed protein spots correspond are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076917#pone-0076917-t002" target="_blank">Table 2</a>.</p