The preparation of zinc ferrite nanorods by using single ferrocenyl complex as precursor

Zinc ferrite nanorods were prepared by the decomposition of ferrocenyl complex [Zn(fca)₂] 1 (Hfca, ferroceneylacetone) as single source precursor. In this work, we presented a new and simple route to synthesize nanostructured ferrites by decomposition of ferrocene-based complexes without the assistance of catalysts or template, and successfully obtained zinc ferrite nanorods with perfect morphology. The synthesis of ZnFe₂O₄ nanorods was carried out via decomposition of zinc ferrocenyl complexes at the presence of sodium hypochlorite under hydrothermal condition without the attendance of catalysts or templates. The results show that ferrocenyl complexes play an important role in the control synthesis of good morphology ferrites. To our knowledge, this is the first report to describe the synthesis of nanostructured zinc ferrites based on one-step hydrothermal decomposition of zinc ferrocenyl complexes. This exploration provides a useful method to seek new nanomaterials with perfect morphology in the shape-controlled synthesis of complicated inorganic composition oxides.     

Preparation of single-crystal copper ferrite nanorods and nanodisks

This article, for the first time, reports the preparation of single-crystal copper ferrite nanorods and nanodisks. Using amorphous copper ferrite nanoparticles synthesized by reverse micelle as reaction precursor, single-crystal copper ferrite nanorods were synthesized via hydrothermal method in the presence of surfactant polyethylene glycol (PEG), however, copper ferrite nanodisks were prepared through the same procedures except the surfactant PEG. The resulting nanomaterials have been characterized by powder X-ray diffraction (XRD), selected electron area diffraction (SEAD), and transmission electron microscopy (TEM). The bulk composition of the samples was determined by means of X-ray photoelectron spectroscopy (XPS).     

A new strategy for the preparation of porous zinc ferrite nanorods with subsequently light-driven photocatalytic activity

Porous zinc ferrite (ZnFe₂O₄) nanorods have been synthesized by the thermal decomposition of ZnFe₂(C₂O₄)₃ nanorods precursor, which was prepared by template-, surfactant-free solvothermal method. The morphology and structure of the obtained ZnFe₂(C₂O₄)₃ nanorods precursor and porous ZnFe₂O₄ nanorods were characterized by X-ray powder diffraction, transmission electron microscopy, field emission scanning electron microscopy and high-resolution transmission electron microscopy. The results indicated that the as-synthesized ZnFe₂O₄ retained the precursor morphology of 1D nanorods with diameters of 100–200 nm and lengths of several micrometers and plenty of nanoparticles were interconnected to each other to form porous nanorods. The as-prepared ZnFe₂O₄ nanorods as a kind of subsequently light-driven photocatalyst exhibited good photocatalytic decomposition activity for methylene blue (MB).     

Production of single and multi-walled carbon nanotubes using natural gas as a precursor compound

In this work, the Catalytic Chemical Vapor Deposition (CCVD) technique was used to synthesize carbon nanotubes (CNT). Natural gas (NG) was employed as a carbon source for the growing of CNT, while magnesium oxide was used as a catalyst support for the nanotubes synthesis. Two systems were utilized. The Fe–Mo/MgO system was obtained by the impregnation technique through the dispersion of iron oxide, which is the catalyst, over magnesia (with molybdenum additions). This system was tested intending to optimize the parameters for the production of single-walled carbon nanotubes (SWCNT). Moreover, Mg_1−x Fe _x MoO₄, which was prepared by the combustion synthesis method, was tested to produce multi-walled carbon nanotubes (MWCNT). The Fe-Mo/MgO tests were carried out under H₂/GN and Ar/GN atmospheres at 950 °C, whereas the Mg_1−x Fe _x MoO₄ was submitted to 1,000 °C under H₂/GN atmosphere. The Fe–Mo/MgO catalyst produced better results regarding number of CNT and their diameters under Ar/NG atmospheres than under H₂/NG atmospheres. The system Mg_1−x Fe _x MoO₄ produced MWCNT according to the expectations.     

Solvothermal synthesis of uniform hexagonal-phase ZnS nanorods using a single-source molecular precursor

Pure and uniform hexagonal-phase ZnS nanorods with quantum confinement effect were synthesized by solvothermal decomposition of an air-stable, easily obtained single-source molecular precursor (zinc diethyldithiocarbamate, Zn-(DDTC)₂) in hydrazine hydrate aqueous solutions at 150–200 °C, and characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and UV–vis absorption spectra. The possible formation mechanism of one-dimensional ZnS nanostructure in the present system was also briefly discussed.     

Ultrasound-induced morphology transformation from 3D microspheres to 1D nanorods of luminescent coordination polymer

Hierarchically spherical architectures self-assembled by nanorods of coordination polymer La(1,3,5-BTC)(H2O)6:Dy3+ have been successfully prepared on a large scale via rapid static growth in solution phase at room temperature. Interestingly, these uniform and well-dispersed 3D microspheres are sensitive to ultrasound, which can be completely transformed into 1D nanorods through simple ultrasonic treatment. The photoluminescence properties of the nano/microstructured La(1,3,5-BTC)(H2O)6:Dy3+ are also investigated in detail, indicating that the obtained lanthanum 1,3,5-benzenetricarboxylate is a new promising host material for the luminescence of Dy3+ ions.     

Sonochemical preparation of silica nanorods for gene delivery using single-walled carbon nanotubes as templates

Silica nanorods were fabricated with single-walled carbon nanotubes (SWCNTs) via ultrasound. The diameter of the resulting SWCNT-silica particles ranged from 60 to 70 nm. The morphology of this composite material was investigated via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The individual SWCNTs are uniformly coated with silica and formed a unique nanocomposite material. The important role of ultrasound and the mechanism of silica layer formation on SWCNTs were explained via the hydrolysis of the silica source and the adsorption of the siloxane groups on the SWCNT surfaces under ultrasound irradiation. The amino-functionalized silica nanorods were demonstrated as non-viral vectors for gene delivery.     

The convenient preparation of porous CuO via copper oxalate precursor

Porous copper oxide has been synthesized via copper oxalate precursor, which was prepared in mild condition without any template or additive. Powder X-ray diffraction, scanning electron microscopy, and nitrogen physisorption method are used to characterize various properties of the obtained samples. SEM analyses show that the precursor morphology was maintained after calcination, and the obtained hierarchically copper oxide was built up of nanocrystals. Nitrogen physisorption analyses show that copper oxide samples were very porous. The porous material could be found application in catalysis field.     

Synthesis and characterization of Mn2O3 nanorods using a novel manganese precursor

The Mn₂O₃ nanorods have been prepared using [Mn(sal)₂] complex as a novel precursor in the presence of sodium dodecyl sulfate (SDS) as surfactant. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. Manganese oxide nanocrystals have been prepared under different condition. The controlled experimental results showed that the ultrasonic irradiation and the use of SDS as the surfactant in the chemical process play important role in the formation of the final products.     

Synthesis ZnO nanoparticles from a new Zinc(II) coordination polymer precursor

A new zinc(II) nitrite coordination polymer, [Zn(3-bpdh)(NO₂)₂]_n (1), 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} was prepared and characterized by elemental analyses and IR spectroscopy. Compound 1 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environment of distorted octahedral, ZnN₂O₄. Thermal decomposition of this precursor in oleic acid at 240 °C under air atmosphere results in the formation of nanoparticles of ZnO. The nano-materials were characterized by scanning electron microscopy, X-ray powder diffraction (XRD) and IR spectroscopy. The thermal stability of nano-structure ZnO was studied by thermal gravimetric and differential thermal analyses and showed that there is no reportable loss of weight in the TGA curves that proves the existence of zinc(II) oxide. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials.     

Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying

Deposition of pure spinel phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 < pH ≤ 10) were found to favor oxide film formation. The nanostructured films produced under optimized conditions, with 500 mM solution at pH ～ 8.0, yielded pure cubic phase ZnFe₂O₄ film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of ～1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications.     

Synthesis of copper and copper(I) oxide nanoparticles by thermal decomposition of a new precursor

The present investigation reports, the novel synthesis of nanoparticles Cu and Cu₂O using thermal decomposition and its physicochemical characterization. The nanoparticles copper powder have been prepared using [Bis(salicylidiminato)copper(II)], [Cu(sal)₂], as precursor. Cu nanoparticles are initially formed and subsequently oxidized to form Cu₂O. Transmission electron microscopy (TEM) analysis demonstrated nanoparticles Cu₂O with an average diameter of about 10 nm. As-prepared copper nano-particles were characterized by X-ray diffraction measurements (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), and Fourier transform infra-red spectroscopy (FTIR). XRD analysis revealed broad pattern for fcc crystal structure of copper metal and cubic cuprite structure for Cu₂O. Optical absorption measured by UV–visible spectroscopy was used to monitor oxidation course of Cu → Cu₂O and to determine the band-gap energy about 2.4 eV for Cu₂O nanoshells.     

A new chemical route for the preparation of fine ferrite powders

Precursors to MFe₂O₄ [spinels ferrites; where M = Ni(II), Co(II) and Zn(II)] have been prepared by the evaporation of polyvinyl alcohol added mixed metal nitratesolution, in presence and absence of urea. Theprecursor materials have low ignition temperature and are spontaneously combustible at low temperatures (250°C to 400°C). The heat liberated through the process is sufficient for the crystallization of the desired ferrite phase. The urea added process resulted in finer, superparamagnetic particles (12–17 nm) compared to the process without urea (particle size 25–30 nm). The ultrafine ferrite powders obtained have been characterized by X-ray powder diffraction (XRD), thermal gravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy (IR), transmission electron microscopy (TEM) and room temperature magnetic measurement studies.     

基于二维长方晶格柱状光子晶体的衍射抑制

通过等频图分析并结合时域有限差分法模拟,基于光子晶体自准直机制可以实现电磁能量高度局域的无衍射光束传播。实验上加工出柱状长方晶格光子晶体,利用红外CCD,在1540nm-1570nm波段范围内观测到0.4mm的自准直传播,通过粒子散射光亮度估算出光子晶体链上传输损耗为17dB/mm。该结构表现出来的宽频性能以及毫米量级的传输距离,使其具有应用在光互连中的潜力。     

Nanocrystalline copper doped zinc oxide produced from copper doped zinc hydroxide nitrate as a layered precursor

Undoped and copper doped nanostructured zinc oxides were synthesized by using a series of synthetic layered material, undoped and copper doped zinc hydroxide nitrates at various molar percentages of copper (2–10) within the layers as precursors. The layered materials were heat-treated at 500 °C to produce zinc oxide nanostructures with crystallite sizes in the range of 23–35 nm. Optical studies of the nanostructured copper doped zinc oxides showed the decrease in band gap with increasing content of the doping agent, copper.     

Synthesis of PbO nano-particles from a new one-dimensional lead(II) coordination polymer precursor

A new Pb(II) one-dimensional coordination polymer, [Pb(µ-NO₂)(µ-pyc)(H₂O)]_n (), Hpyc = 2-pyridinecarboxylic acid} was prepared and characterized by elemental analyses, powder XRD diffraction and IR spectroscopy. Compound 1 was structurally characterized by single-crystal X-ray diffraction and one-dimensional coordination polymer with coordination environment of PbNO₆. The thermal stability of compound 1 showed that compound 1 decomposes at 110-500 °C and the final product is PbO. This polymeric precursor has been used to make PbO nano-particles using two different surfactants. The new nano-structure was characterized by scanning electron microscopy and X-ray powder diffraction. This study demonstrates that the coordination polymers may be suitable precursors for the preparation of nanoscale materials.     

平炉尘合成超细铁氧体机理研究

平炉炼钢产生大量平炉尘。内蒙古包头钢铁公司的平炉尘主要成分是立方晶系的γ-Fe2O3。我们利用同晶型间的拓扑转化原理,使平炉尘转化为超细尖晶石型铁氧体磁性粉末。并和离子反应对比．研究了固液界面反应机理。本实验为制备超细铁氧体磁性粉末和资源综合利用及减少环境污染提供了新方法。     

Synthesis of aluminum borate nanorods by a low-heating-temperature solid-state precursor method

Well-crystalline Al₄B₂O₉ nanorods were synthesized by a low-heating-temperature solid-state precursor method. This process does not involve the use of metal catalyst or protective gas. The products were characterized by thermogravimetry and differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed the products to possess a single phase, large surface area, narrow size distribution of 20-30 nm and lengths up to several micrometers. A self-catalytic growth mechanism of the aluminum borate nanorods is proposed.     

Nanocrystalline copper ferrite: synthesis of different shapes through a new method and its photocatalyst application

Pure CoFe₂O₄ nanostructures were prepared via auto-combustion sol–gel method in presence of different amino acids as a natural fuel. The effect of different amino acids such as leucine, asparagine, and alanine on the size, and morphology of CoFe₂O₄ nanostructures were investigated. The as-obtained CoFe₂O₄ nanostructures were analyzed by UV–Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray microanalysis, and X-ray diffraction. The magnetic properties of as-prepared CoFe₂O₄ nanostructures were also investigated with vibrating sample magnetometer. In addition, methyl orange was chosen as a dye water pollution to evaluate its degradation by as-synthesize CoFe₂O₄ under ultraviolet light irradiation. Furthermore, the photocatalysis results reveal that the maximum decolorization of 82 % for methyl orange occurred with CoFe₂O₄ nanoparticles in 90 min under ultraviolet (UV) light irradiation.