氧化铁纳米线阵列的溶胶-凝胶模板法制备与表征

0引言氧化铁在颜料、磁记录材料和催化剂等方面具有广泛的应用[1,2]。尤其是纳米氧化铁在纳米尺度具有良好的气敏特性[3]。纳米材料可以分为零维、一维、二维纳米材料,一维材料是纳米材料的重要组成部分,是纳米组装的基础。一维纳米材料的制备方法中氧化铝模板法占有极其重要的     

Direct electrodeposition of highly dense Bi/Sb superlattice nanowire arrays

Ordered arrays of Bi/Sb superlattice nanowires with diameters of about 50 nm have been produced by pulsed electrodeposition technique into the pores of anodic alumina membrane (AAM). The structure of Bi/Sb superlattice nanowire can be modulated by controlling the electrodeposition conditions.     

Size-dependent orientation growth of large-area ordered Ni nanowire arrays

Large-area ordered Ni nanowire arrays with different diameters have been fabricated by the direct current electrodeposition into the holes of porous anodic alumina membrane. The crystal structure and micrograph of nanowire arrays are characterized by X-ray diffraction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The results indicate that the growth orientation of Ni nanowires turns from [110] to [111] direction with increasing diameters of nanowires. The mechanism of the growth was discussed in terms of interface energy minimum principle. The size-dependent orientation of Ni nanowire arrays has the important significance for the design and control of nanostructures.     

Fabrication and characterization of single-crystalline ZnTe nanowire arrays

Semiconductor ZnTe nanowire arrays have been synthesized by the pulsed electrochemical deposition from aqueous solutions into porous anodic alumina membranes. X-ray diffraction analyses show that the as-synthesized nanowires have a highly preferential orientation. Scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy indicate that high-filling, ordered, and single-crystalline nanowire arrays have been obtained. The optical absorption spectra of the nanowire arrays show that the optical absorption band edge of the ZnTe nanowire array exhibits a blue shift compared with that of bulk ZnTe. The growth mechanism and the electrochemical deposition process are discussed together with the chemical compositions analysis.     

Sb有序单晶纳米线阵列的制备

采用直流电沉积的方法在氧化铝模板（AAM）中成功地制备了Sb单晶纳米线阵列. X射线衍射（XRD）证明所制得的纳米线阵列为(110)取向的六方相Sb.透射电镜（TEM）显示Sb纳米线平滑而均匀,直径40～50 nm,长径比大于1000.选区电子衍射（SAED）结果表明,所制得的纳米丝为Sb单晶丝.场发射扫描电镜（FE-SEM）显示Sb纳米线阵列规则,填充率接近100％.     

金纳米线阵列制备及其光谱特性

利用电化学沉积方法在重离子径迹模板中制备出直径从45 nm到200 nm, 长径比达700的金纳米线阵列, 利用扫描电子显微镜(SEM)和X射线衍射(XRD)对所制备金纳米线的形貌及晶体结构进行分析, 结果表明, 在1.5 V(无参比电极)沉积电压下所制备出的直径为200 nm金纳米线沿[100]晶向具有较好择优取向. 利用紫外-可见光谱(UV-Vis)对镶嵌在透明模板中平行排列的金纳米线阵列光学特性进行研究, 发现金纳米线直径为45 nm时, 其紫外可见光谱在539 nm处有强烈吸收峰, 随着金纳米线直径增加, 吸收峰红移, 当金纳米线直径达到200 nm时, 其吸收峰峰位移至700 nm. 结合金纳米颗粒相关表面等离子体共振吸收效应对实验结果进行了讨论.     

InSb纳米线阵列的可控制备与光谱表征

采用脉冲电沉积结合阳极氧化铝模板技术制备了不同生长方向的闪锌矿型InSb纳米线阵列. 结果表明, 控制电解液中十二烷基硫酸钠(SDS)的浓度, 可使纳米线的择优生长方向从[400]向[220]方向转变. 利用X射线衍射仪、 场发射扫描电子显微镜、 高分辨透射电子显微镜对所制备纳米线的相组成和微结构进行了表征. 激光拉曼光谱结果表明, 不同生长方向的InSb纳米线阵列的拉曼光谱有明显差异. 与体材料相比, InSb纳米线阵列的红外吸收声子散射峰发生强烈红移, 其吸收带边发生了明显蓝移.     

Photoluminescence and Raman scattering from catalytically grown Zn(x)Cd(1-x)Se alloy nanowires

Zn(x)Cd(1-x)Se alloy nanowires, with composition x = 0, 0.2, 0.5, 0.7, and 1, have been successfully synthesized by a chemical vapor deposition (CVD) method assisted with laser ablation. The as-synthesized alloy nanowires, 60-150 nm in diameter and several tens of micrometers in length, complied with a typical vapor-liquid-solid (VLS) growth mechanism. The Zn(x)Cd(1-x)Se nanowires are single crystalline revealed from high-resolution transmission electron microscopic (HRTEM) images, selected area electron diffraction (SAED) patterns, and X-ray diffraction (XRD) measurement. Compositions of the alloy nanowires can be adjusted by varying the precursor ratios of the laser ablated target and the CVD deposition temperature. Crystalline structures of the Zn(x)Cd(1-x)Se nanowires are hexagonal wurtzite at x = 0, 0.2, and 0.5 with the [0 1 -1 0] growth direction and zinc blende at x = 0.7 and 1 with the [1 -1 1] growth direction. Energy gaps of the Zn(x)Cd(1-x)Se nanowires, determined from micro-photoluminescence (PL) measurements, change nonlinearly as a quadratic function of x with a bowing parameter of approximately 0.45 eV. Strong PL from the Zn(x)Cd(1-x)Se nanowires can be tuned from red (712 nm) to blue (463 nm) with x varying from 0 to 1 and has demonstrated that the alloy nanowires have potential applications in optical and sensory nanotechnology. Micro-Raman shifts of the longitudinal optical (LO) phonon mode observed in the Zn(x)Cd(1-x)Se nanowires show a one-mode behavior pattern following the prediction of a modified random element isodisplacement (MREI) model.     

CdSe纳米线阵列的制备及其表征(英)

通过在含有SeSO₃^2-和Cd²⁺的室温水溶液中，用模板-电沉积法在纳米孔阵列阳极氧化铝膜(AAM)模板中制备了高有序性的CdSe纳米线阵列，并对其形貌、结构和组分进行了表征。扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明，纳米线阵列中的CdSe纳米线具有相同的长度和直径，分别对应于使用的AAM模板的厚度和孔径；X-射线衍射(XRD)和X-射线能谱(EDAX)结果表明，CdSe纳米线中Cd和Se的化学组成非常接近于1∶1，其结构为立方CdSe。另外，对模板-电沉积法制备CdSe纳米线的机理进行了讨论。     

铅纳米线阵列的制备

使用电化学沉积方法,在有序的氧化铝模板(AAO)孔洞中制备了铅纳米线有序阵列。用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)对样品的结构、形貌、进行表征和观测。XRD的结果表明所制备的样品为纯的立方面心铅,且纳米线生长沿<220>有很好的取向。FE-SEM的图片清晰地说明铅纳米线阵列是大面积、高填充率和高度有序的。TEM的结果显示纳米线直径均匀、表面光滑且长径比大。     

大面积Bi单晶纳米线阵列的制备

在有序的氧化铝模板(AAO)的孔洞中, 采用电化学沉积工艺成功地制备了准金属Bi纳米线有序阵列. 使用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)及高分辨电子显微镜(HRTEM)对样品的结构和形貌进行了表征. XRD结果表明, 所制备的铋样品为六方相, 且沿[110]方向有很好的生长取向; FE-SEM图片清晰地说明铋纳米线阵列是大面积、填充率高和高度有序的; TEM的结果显示纳米线直径均匀、表面光滑且长径比大; HRTEM图片中清晰的晶格条纹和选区电子衍射(SAED)结果表明纳米线是单晶.     

Growth of single-crystalline Ni and Co nanowires via electrochemical deposition and their magnetic properties

Single-crystalline Ni nanowires have been successfully fabricated with anodic aluminum oxide as template by electrodeposition. Structural characterization (X-ray diffraction, XRD, and high-resolution transmission electron microscopy, HRTEM) shows that the single-crystalline Ni nanowire has a preferred orientation along the [220] direction. The effects of electrochemical deposition conditions on the structure of Ni nanowires are systematically studied to investigate the growth mechanism. Possible reasons for the growth of the single-crystalline Ni nanowires were discussed on the basis of electrochemistry and thermodynamics. These single-crystalline Ni nanowires have exhibited excellent magnetic properties (large anisotropy, large coercivity, and high remanence). By a similar process, single-crystalline Co nanowires with hexagonal close-packed (hcp) structure were achieved, also having large anisotropy, large coercivity (1.8 kOe), and high remanence ratio (80.8%).     

High-quality ultralong Bi2S3 nanowires: structure, growth, and properties

A simple one-step hydrothermal method for large-scale synthesis of ultralong single-crystalline Bi2S3 nanowires was reported, and the nanowires were comprehensively characterized. The diameters of the nanowires are about 60 nm, and their lengths range from tens of microns to several millimeters. The structure of the nanowires was determined to be of the orthorhombic phase, the growth direction was along [001], and the growth mechanism was investigated based on extensive high-resolution transmission electron microscopy observations. Optical absorption experiments revealed that the Bi2S3 nanowires are narrow-band semiconductors with a band gap E(g) approximately 1.33 eV. Electrical transport measurements on individual nanowires gave a resistivity of about 1.2 ohms cm and an emission current of 3.5 microA at a bias field of 35 V/microm. This current corresponds to a current density of about 10(5) A/cm2, which makes the Bi2S3 nanowire a potential candidate for applications in field-emission electronic devices.     

Metallic single-crystal CoSi nanowires via chemical vapor deposition of single-source precursor

We report the synthesis, structural characterization, and electrical transport properties of free-standing single-crystal CoSi nanowires synthesized via a single-source precursor route. Nanowires with diameters of 10-150 nm and lengths of greater than 10 mum were synthesized through the chemical vapor deposition of Co(SiCl(3))(CO)(4) onto silicon substrates that were covered with 1-2 nm thick SiO(2). Transmission electron microscopy confirms the single-crystal structure of the cubic CoSi. X-ray absorption and emission spectroscopy confirm the chemical identity and show the expected metallic nature of CoSi, which is further verified by room-temperature and low-temperature electrical transport measurements of nanowire devices. The average resistivity of CoSi nanowires is found to be about 510 muOmega cm. Our general and rational nanowire synthesis approach will lead to a broad class of silicide nanowires, including those metallic materials that serve as high-quality building blocks for nanoelectronics and magnetic semiconducting Fe(1-x)Co(x)Si suitable for silicon-based spintronics.     

Temperature-Dependent Electrical Conductance of Bi Nanowires

The single crystal bismuth nanowire arrays grown along [0112] with the diameter of 30 nm was synthesized in the pore of anodic aluminum oxide templates through electrodeposi-tion process. The temperature dependent electric conductance of Bi nanowire arrays was measured from 78 K to 320 K. We found that the semimetal-to-semiconductor transition happened around 230 K for 30 nm Bi nanowires oriented along [01112] and the electric con-ductance of the nanowires had a strong temperature dependence.     

Direct electrodeposition of FeCoZn wire arrays from a zinc chloride-based ionic liquid

The use of Zinc chloride-1-ethyl-3-methylimidazolium chloride ionic liquid enables facile template-free electrochemical fabrication of arrays of polycrystalline ternary FeCoZn nanowires with diameter of 100–200 nm by controlling the deposition potential. The nanowire arrays were characterized by scanning electron microscopy, powder X-ray diffraction and transmission electron microscopy.     

重离子径迹模板法合成银纳米线

聚碳酸脂(PC)膜被高能重离子辐照后沿入射离子路径产生潜径迹, 把带有潜径迹的膜经紫外光敏化后置于NaOH 溶液中进行蚀刻, 通过选择蚀刻条件, 在PC 膜内得到直径从100 到500 nm 导通的核径迹孔. 以带有核径迹孔的PC 膜为模板, 用电化学沉积法制备出不同直径的银纳米线. 在特定的实验条件下(沉积电压25mV、电流密度1-2 mA·cm-2、温度50 益和电解液为0.1 mol·L-1的AgNO3溶液), 获得了沿[111]方向择优取向生长的具有单晶结构的银纳米线. 利用扫描电子显微镜(SEM)、X射线衍射(XRD)、透射电子显微镜(TEM)及选区电子衍射(SAED)等手段对银纳米线的形貌和晶体结构特征进行了表征.     

Electrodeposition of Bi(x)Fe(1-x) intermetallic compound nanowire arrays and their magnetic properties

There have been few reports on Bi-Fe intermetallic compounds because Bi and Fe are immiscible in the equilibrium states and neither alloy nor intermetallic compound exists in the binary system. In this paper, we show that, by using the nanometer-scale templates based synthesis in conjunction with the electrochemical deposition, it is possible to mix in solid solution elements that are immiscible in traditional fabrication methods. The preparation of Bi-Fe intermetallic compound nanowire arrays was investigated via an electrodeposition route by using a polycarbonate (PC) membrane template. Cyclic voltammetry, potentiostatic transient, and potentiostatic stripping were used to study the formation of Bi(x)Fe(1-x) intermetallic compounds. The compositions of Bi(1-x)Fe(x) intermetallic compound nanowire arrays were sensitive to the bath compositions and the electrodeposition potentials, and the length could be easily adjusted by varying the electrodeposition time. The electrodeposited Bi(1-x)Fe(x) intermetallic compound nanowire arrays had a parallel-to-the-wire easy magnetization. Furthermore, the spin-glass such as behavior and an unusually large characteristic time, which was about 5.26 h, were found in Bi(1-x)Fe(x) intermetallic compound nanowire arrays at room temperature.     

Controlled growth of semiconducting oxides hierarchical nanostructures

Semiconducting ZnO hierarchical nanostructure, where ZnO nanonails were grown on ZnO nanowires, has been fabricated under control experiment with a mixture of ZnO nanopowders and Sn metal powders. Sn nanoparticles are located at or close to the tips of the nanowires and the growth branches, serving as the catalyst for the vapor-liquid-solid growth mechanism. The morphology and microstructure of ZnO nanowire and nanonail were measured by scanning electron microscopy and high-resolution transmission electron microscopy. The long and straight ZnO nanowires grow along [0001] direction. ZnO nanonails are aligned radially with respect to the surface the ZnO nanowire. The long axis direction of nanonails forms an angle of ∼30° to the [0001] direction.     

Template-directed synthesis of ordered single-crystalline nanowires arrays of Cu2ZnSnS4 and Cu2ZnSnSe4

Highly ordered quaternary semiconductor Cu(2)ZnSnS(4) nanowires array have been prepared via a facile solvothermal approach using anodic aluminum oxide (AAO) as a hard template. The as-prepared nanowires are uniform and single crystalline. They grow along either the crystalline [110] or [111] direction. The structure, morphology, composition, and optical absorption properties of the as-prepared Cu(2)ZnSnS(4) samples were characterized using X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray spectrometry, scanning electron microscopy, and UV-vis spectrometry. A possible formation mechanism of the nanowire arrays is proposed. Governed by similar mechanism, we show that Cu(2)ZnSnSe(4) nanowire array with similar structural characteristics can also be obtained.