苝四甲酸二酐有机单晶纳米结构的制备及形成机理的研究

在分子束外延(MBE)系统中, 利用物理气相沉积(PVD)的方法在阳极氧化铝(AAO)模板上制备了有机 染料分子苝四甲酸二酐(PTCDA)的不同纳米结构; 并使用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、 高分辨透射电子显微镜(HRTEM)以及选区电子衍射(SAED)技术进行了系统的研究. 结果发现, 当衬底温度(T_s)为330 ℃时得到的是纳米丝、针、带以及棒; T_s为280 ℃, 230 ℃, 180 ℃时得到的主要是纳米棒, 并且纳米棒的长度随T_s的降低而变短; T_s为50 ℃时只能得到连续的PTCDA薄膜. HRTEM以及SAED结果证实了纳米针与棒为单晶. 依据SEM结果, 提出纳米结构的生成主要受T_s以及衬底表面曲率的影响.     

LaPO4:Eu3+@SiO2核壳结构发光纳米棒的制备与表征

在不加任何表面活性剂的条件下,通过水热法直接合成了LaPO4:Eu3+纳米棒,并采用溶胶-凝胶法在其表面修饰了一层SiO2,得到了LaPO4:Eu3+@SiO2纳米棒.XRD分析表明,样品包覆前后均属于单斜晶系的独居石型的LaPO4.FTIR分析表明,LaPO4:Eu3+粒子与SiO2是以化学键的形式结合在一起.由TE...     

Sonochemical synthesis of silver vanadium oxide micro/nanorods: Solvent and surfactant effects

In this investigation, a facile sonochemical route has been developed for the preparation of silver vanadium oxide (SVO) micro/nanorods by using silver salicylate and ammonium metavanadate as silver and vanadate precursor, respectively. Here, silver salicylate, [Ag(HSal)], is introduced as a new silver precursor to fabricate AgVO₃ nanorods. The effect of numerous solvents and surfactants on the morphology and sonochemical formation mechanism of AgVO₃ nanorods was studied. AgVO₃ nanorods were characterized by SEM and TEM images, XRD patterns, FT-IR, XPS, and EDS spectroscopy. SEM, TEM, and XRD results showed that AgO nanoparticles were formed onto AgVO₃ nanorods in the presence of ethanol, cyclohexanol, dimethylsulfoxide (DMSO), and acetone. By using polyethylene glycol (PEG-6000) and N,N-dimethylformamide (DMF) as organic additives, the thickness of AgVO₃ nanorods decreased.     

Synthesis and characterization of Gd(OH)3 nanobundles

Gd(OH)₃ nanobundles, which consisted of bundle-like nanorods, have been prepared through a simple and facile hydrothermal method. The crystal, purity, morphology and structural features of Gd(OH)₃ nanobundles are investigated by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy dispersive X-ray (EDX). A possible formation mechanism of Gd(OH)₃ nanobundles is briefly discussed.     

Thioglycolic acid (TGA) assisted hydrothermal synthesis of SnS nanorods and nanosheets

Nanorods and nanosheets of tin sulfide (SnS) were synthesized by a novel thioglycolic acid (TGA) assisted hydrothermal process. The as prepared nanostructures were characterized by X-ray diffraction (XRD) study, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD study reveals the formation of well-crystallized orthorhombic structure of SnS. Diameter of the SnS nanorods varied within 30-100 nm. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) patterns identify the single crystalline nature for the SnS nanocrystals. The mechanism for the TGA assisted growth for the nanosheets and nanorods have been discussed.     

Growth of ZnO nanorods by aqueous solution method with electrodeposited ZnO seed layers

ZnO nanorod arrays on ZnO-coated seed layers were fabricated by aqueous solution method using zinc nitrate and hexamethylenetetramine at low temperature. The seed layers were coated on ITO substrates by electrochemical deposition technique, and their textures were dominated by controlling the deposition parameters, such as deposition potential and electrolyte concentration. The effects of the electrodeposited seed layers and the growing parameters on the structures and properties of ZnO nanorod arrays were primarily discussed. The orientation and morphology of both the seed layer and successive nanorods were analyzed by using X-ray diffraction (XRD), SEM and TEM. The results show that the seed layer deposited at −700 mV has evenly distributed crystallites and (0 0 2) preferred orientation; the density of resultant nanorods is high and ZnO nanorods stand completely perpendicular onto substrates. Meanwhile, the size of nanorods quite also depends on the growth solution, and the higher concentration of growth solution primary leads to a large diameter of the ZnO nanorods.     

New voltammetric strategy for simultaneous determination of norepinephrine, acetaminophen, and folic acid using a 5-amino-3′,4′-dimethoxy-biphenyl-2-ol/carbon nanotube paste electrode

A carbon paste electrode modified with 5-amino-3??,4??-dimethoxy-biphenyl-2-ol and carbon nanotubes was used for the sensitive voltammetric determination of norepinephrine (NE). The electrochemical response characteristics of the modified electrode toward NE, acetaminophen (AC), and folic acid (FA) were investigated by cyclic and square wave voltammetry (SWV). The results show an efficient catalytic activity of the electrode for the electrooxidation of NE, which leads to lowering its overpotential more than 160?mV. The modified electrode exhibits an efficient electron-mediating behavior together with well-separated oxidation peaks for NE, AC, and FA. Under the optimum pH of 7.0 in 0.1?M phosphate buffer solution, the SWV anodic peak current showed a linear relation vs. NE concentration in the range of 15.0 to 1,000.0???M with a detection limit of 8.0???M.     

Synthesis of [100] Wurtzite InN Nanowires and [011] Zinc-Blende InN Nanorods

One-dimensional wurtzite InN nanowires and zincblende InN nanorods are prepared by chemical vapour deposition （CVD） method on natural cleavage plane （110） of GaAs. The growth direction of InN nanowires is [100], with wurtzite structure. The stable crystal structure of InN is wurtzite （w-InN）, zincblende structure （z-InN） is only reported for 2D InN crystals before. However, in this work, the zincblende InN nanorods [011] are synthesized and characterized. The SEM and TEM images show that every nanorod shapes a conical tip, which can be explained by the anisotropy of growth process and the theory of Ehrlich Schwoebel barrier.     

Synthesis of single-crystalline hollow β-FeOOH nanorods <Emphasis Type="Italic">via</Emphasis> a controlled incomplete-reaction course

The single-crystalline β-FeOOH hollow nanorods with a diameter ranging from 20∼30 nm and length in the range of 70–110 nm have been successfully synthesized through a two-step route in the solution. The phase transformation and the morphologies of the hollow β-FeOOH nanorods were investigated with X-ray powdered diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electric diffraction (SAED), high-resolution transmission electron microscopy (HRTEM), infrared spectrum (IR) and thermo-gravimetric analysis (TGA). These studies indicate that the first step is an incomplete-reaction course. Furthermore, The formation mechanism of the hollow nanorods has been discussed. It is found that the mixed system including chitosan and n-propanol is essential for the final formation of the hollow β-FeOOH nanorods.     

Facile Synthesis of Single‐Phase Mesoporous Gd2O3:Eu Nanorods and Their Application for Drug Delivery and Multimodal Imaging

In this work, a new and facile strategy is developed to synthesize a single‐phase Eu³⁺‐doped mesoporous gadolinium oxide nanorods (MS‐Gd₂O₃:Eu@PEG) by incorporating a facile wet‐chemical route, which includes an induced silica layer being coated onto the nanorods, and evolution of pores and formation of channels, as well as a surface‐modified process for multimodal imaging and anti‐cancer drug delivery. The properties of these as‐prepared Gd₂O₃:Eu nanorods are characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD), N₂ adsorption/desorption, and photoluminescence (PL). The in vitro cytotoxicity test, drug loading, and drug release experiments reveal that the MS‐Gd₂O₃:Eu@PEG nanorods have good biocompatibility, efficient loading capacity, and pH‐sensitive releasing behavior, suggesting the nanorods could be an ideal candidate as drug delivery vehicles for cancer therapy. Furthermore, the MS‐Gd₂O₃:Eu@PEG nanorods show clearly dose‐dependent contrast enhancement in T₁‐weighted magnetic resonance images and can potentially be used as a T₁‐positive contrast agent. These results indicate our prepared multifunctional mesoporous gadolinium oxide nanorods can serve as a promising platform for simultaneous anti‐cancer drug delivery and multimodal imaging.     

C自掺杂TiO2纳米棒的制备与光催化性能研究

本文以TiC为前驱体和掺杂源,采用一步水热法合成了具有可见光吸收的C自掺杂金红石相TiO_2纳米棒.样品的结构、形貌、化学态和光学性质等可通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FT-IR)、X射线光电子能谱仪(XPS)以及紫外可见分光光度计(UV-vis)来表征.所合成的样品具有较强的光催化活性,可通过在可见光照射下降解有机染料罗丹明B(RhB)来验证.C自掺杂TiO_2所呈现的较强光催化活性是由于其具有小的能带间隙(2.74 eV)、大的比表面积和高的电子-空穴对分离率.     

C自掺杂TiO2纳米棒的制备与光催化性能研究

本文以TiC为前驱体和掺杂源,采用一步水热法合成了具有可见光吸收的C自掺杂金红石相TiO2纳米棒．样品的结构、形貌、化学态和光学性质等可通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、傅里叶变换红外光谱仪（FT-IR）、X射线光电子能谱仪（XPS）以及紫外可见分光光度计（UV-vis）来表征．所合成的样品具有较强的光催化活性,可通过在可见光照射下降解有机染料罗丹明B（RhB）来验证．C自掺杂TiO2所呈现的较强光催化活性是由于其具有小的能带间隙（2.74 eV）、大的比表面积和高的电子-空穴对分离率．     

C自掺杂TiO2纳米棒的制备与光催化性能研究

本文以TiC为前驱体和掺杂源,采用一步水热法合成了具有可见光吸收的C自掺杂金红石相TiO2纳米棒．样品的结构、形貌、化学态和光学性质等可通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、傅里叶变换红外光谱仪（FT-IR）、X射线光电子能谱仪（XPS）以及紫外可见分光光度计（UV-vis）来表征．所合成的样品具有较强的光催化活性,可通过在可见光照射下降解有机染料罗丹明B（RhB）来验证．C自掺杂TiO2所呈现的较强光催化活性是由于其具有小的能带间隙（2.74 eV）、大的比表面积和高的电子-空穴对分离率．     

Synthesis of VO2 (B) nanorods for Li battery application

Vanadium dioxide nanorods were synthesized through a hydrothermal reaction from V₂O₅ xerogel, poly(vinyl pyrrolidone) (PVP) and lithium perchlorate (LiClO₄). The prepared samples were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical discharge–charge cycling in lithium battery. SEM images reveal the nanorods to have dimensions on the order of 1–3 μm in length and 10–50 nm in diameter. The measured initial discharge capacity of the lithium battery with a cathode made of VO₂ (B) nanorods was 152 mA h/g.     

乙二醇对反向微乳辐照法制备纳米级氧化亚铜形貌的影响

在乙二醇存在下,采用反向微乳辐照法制备了纳米级氧化亚铜(Cu2O)立方体.利用吸收光谱、X射线粉末衍射(XRD)、透射电镜(TEM)、高分辨透射电镜(HRTEM)、扫描电镜(SEM)等对所得产物进行了表征.吸收光谱显示随着乙二醇用量逐渐增加,Cu2O的半导体激子吸收特征峰逐渐增强并且红移,初步表明所得产物的粒径逐渐增大.常规透射电镜的结果表明所得Cu2O的纳米颗粒的粒径逐渐增大,并且变得规整.实验结果表明,乙二醇对Cu2O纳米粒子的形貌具有重要影响.乙二醇的存在增大了微乳水池粘度,而粘度大小影响水化电子的反应性,从而影响Cu2O的生成速率、结晶过程.它还可以降低微乳界面刚性,增大水池间的物质交换而影响Cu2O的成核和结晶;此外,它对Cu2O特定晶面的吸附影响其最终形貌.     

Fabrication of Ni-P/palygorskite core-shell linear powder via electroless deposition

Palygorskite is a kind of hydrated magnesium aluminium silicate clay mineral. A novel linear core-shell structured Ni-P coated micro-fiber palygorskite (MFP) was fabricated via an electroless (EL) plating process in an alkaline bath. The composition, morphology and structure of the as-prepared products were characterized by the techniques such as powder X-ray diffraction (XRD), energy-dispersive X-ray spectrum (EDS), scanning electron microscopy (SEM) and transmission electron microscope (TEM). It was observed that the size and morphology of Ni-P coated MFPs were altered by depositing temperature and time. The as-prepared Ni-P coated MFPs showed good conductivity. To the best of our knowledge, the Ni-P coated MFPs have not been reported before. And this fabrication process might also apply in preparing other metal coated MFPs such as silver, copper and palladium.     

Hexagonal nanorods of tungsten trioxide: Synthesis, structure, electrochemical properties and activity as supporting material in electrocatalysis

Tungsten trioxide, unhydrated with hexagonal structure (h-WO₃), has been prepared by hydrothermal method at a temperature of 180 °C in acidified sodium tungstate solution. Thus prepared h-WO₃ has been characterized by X-ray diffraction (XRD) method and using electrochemical techniques. The morphology has been examined by scanning and transmission electron microscopies (SEM and TEM) and it is consistent with existence of nanorods of 50-70 nm diameter and up to 5 μm length. Cyclic voltammetric characterization of thin films of h-WO₃ nanorods has revealed reversible redox behaviour with charge-discharge cycling corresponding to the reversible lithium intercalation/deintercalation into the crystal lattice of the h-WO₃ nanorods. In propylene carbonate containing LiClO₄, two successive redox processes of hexagonal WO₃ nanorods are observed at the scan rate of 50 mV/s. Such behaviour shall be attributed to the presence of at least two W atoms of different surroundings in the lattice structure of h-WO₃ nanorods. On the other hand, in aqueous LiClO₄ solution, only one redox process is observed at the scan rate of 10 mV/s. The above observations can be explained in terms of differences in the diffusion of ions inside two types of channel cavities existing in the structure of the h-WO₃ nanorods. Moreover, the material can be applied as active support for the catalytic bi-metallic Pt-Ru nanoparticles during electrooxidation of ethanol in acid medium (0.5 mol dm⁻³ H₂SO₄).     

Ultrasonic-assisted environmentally-friendly synergetic synthesis of nitroaromatic compounds in core/shell nanoreactor: A green protocol

An efficient sonochemical protocol for the nitration of aromatic compounds was described in the presence of a catalytic amount of sulfuric acid-functionalized silica-based core/shell magnetic nanocomposite at room temperature in an eco-friendly and recyclable media, deep eutectic solvent (DES), based on choline chloride and urea. The particle size, morphology and elemental analysis of the core/shell nanocatalyst were carried out by TEM, SEM, EDX and XRD analyses. The nanocatalyst and DES were easily recovered from the reaction mixture quantitatively and reused several times.     

Preparation and characterization of SrSnO3 nanorods

Perovskite strontium stannate (SrSnO₃) nanorods were prepared by annealing the precursor SnSr(OH)₆ nanorods at 600 °C for 3 h. The precursor nanorods were hydrothermally synthesized at 160 °C for 16 h using Sr(NO₃)₂ and SnCl₄·5H₂O as starting materials in the presence of surfactant cetyltrimethyl ammonium bromide (CTAB). As-prepared samples were characterized by X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and infrared ray spectroscopy (IR). The results show that the as-synthesized powders are made of SrSnO₃ one-dimensional nanorods of about 0.2-1 μm length and 100-150 nm diameter. Possible formation mechanism of SrSnO₃ with nanorod structure under certain conditions was preliminarily analyzed, in which it was thought that CTAB played an important role in the formation process of the nanorod structure. Electrochemical performance of the samples versus Li metal was also evaluated for possible use in lithium-ion batteries.     

Controllable synthesis of highly ordered Ag nanorod arrays by chemical deposition method

Highly ordered Ag nanorod arrays were successfully fabricated using a simple chemical deposition method with the assistance of porous alumina membrane (PAM) template. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ag⁺ ions in the PAM nanochannels were reduced by acetaldehyde reagent and resulting in the formation of rod array structures. It is found that the diameter of the Ag nanorods is determined by the PAM template, and the length of the Ag nanorods is depended on the reaction temperature. The growth mechanism of the Ag nanorod arrays is investigated in the study.