Fe-Co-Ni合金纳米线有序阵列的模板合成与磁性

以二次阳极氧化的氧化铝膜为模板，用电化学沉积的方法成功地合成了Fe-Co-Ni三组份有序纳米线阵列.扫描电子显微镜（SEM）和透射电子显微镜(TEM)观察表明纳米线表面光滑、有序、高长径比；磁性测量表明,其矫顽力较同组份的膜材料有较大的提高.将样品在惰性气体氛围中不同温度下退火，随着退火温度增加，其纵向矫顽力有一个极值，而对应的横向矫顽力没有类似的变化，关于这一现象的机理,本文进行了初步的讨论. 图5参15     

有序CdS纳米线阵列的制备和光学特性

应用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,并由XRD、Raman、SEM、TEM和HRTEM等进行物理化学表征.结果表明,沉积在多孔氧化铝模板中的CdS呈六角结构,c轴沿孔长度方向定向生长.紫外吸收光谱研究表明,随着纳米线尺寸的减小,纳米线阵列的吸收边向短波长方向移动,荧光光谱测量显示,CdS纳米线阵列的荧光强度高于氧化铝模板,而且在可见光区的荧光特性与激发波长无关.     

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.     

Large-area Sb2Te3 nanowire arrays

High-density large-area nanowire arrays of thermoelectric material Sb(2)Te(3) have been successfully prepared using electrochemical deposition into the channels of the porous anodic alumina membrane. The morphologies, structure, and composition of the as-prepared Sb(2)Te(3) nanowires have been characterized using field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Individual Sb(2)Te(3) nanowires are single crystalline and continuous with uniform diameters ( approximately 50 nm) throughout the entire length. The atomic ratio of Sb to Te is very close to the 2:3 stoichiometry.     

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％.     

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.     

Ordered nickel oxide nanowire arrays and their optical absorption properties

Ordered NiO nanowire arrays embedded in anodic alumina membranes have been prepared by using an electrochemical deposition method. After annealing at 300 °C, the NiO nanowire arrays were characterized using SEM, TEM, SAED, and XRD. SEM and TEM observations reveal that these nanowires are dense, continuous and arranged roughly parallel to one another. XRD and SAED analysis together indicate that these NiO nanowires crystallize with a polycrystalline structure. The optical absorption band gap of NiO nanowire arrays is 3.74 eV, and no obvious blue shift or red shift with respect of that of the bulk NiO can be observed.     

Large-area highly-oriented SiC nanowire arrays: synthesis, Raman, and photoluminescence properties

Large-area highly oriented SiC nanowire arrays have been fabricated by chemical vapor reaction using an ordered nanoporous anodic aluminum oxide (AAO) template and a graphite reaction cell. Their microstructures were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy. The results show that the nanowires are single-crystalline beta-SiC's with diameters of about 30-60 nm and lengths of about 8 microm, which are parallel to each other, uniformly distributed, highly oriented, and in agreement with the nanopore diameter of the applied AAO template. The nanowire axes lie along the [111] direction and possess a high density of planar defects. Some unique optical properties are found in the Raman spectroscopy and photoluminescence emission from oriented SiC nanowire arrays, which are different from previous observations of SiC materials. The growth mechanism of oriented SiC nanowire arrays is also analyzed and discussed.     

大长径比有序多孔阳极氧化铝模板的制备及用于镍纳米线阵列

报道一种恒电流二次氧化制备大长径比(>1000)阳极氧化铝(AAO)模板的方法,研究氧化时间和氧化电流密度分别对制备的AAO模板的表面形貌、孔径大小、厚度等的影响.结果表明,AAO模板的表面形貌及厚度n受m氧、厚化度电约流为密2度00及μ氧m、化长时径间比的为影10响0;-当13氧00化的电高流质密量度A为AO8模m板A·.c采m用-2电时化,氧学化沉1积8方h能法在制制备备出的孔A径A为O模15板0-的20孔0中成功制备了Ni纳米线阵列,分别用扫描电镜(SEM)、高分辨透射电镜(HRTEM)、X射线衍射(XRD)和X射线能量散射光谱(EDS)对其进行了表征;结果显示,制备的Ni纳米线排列整齐有序,每根Ni纳米线直径几乎相同,约150nm,长度约为180-200μm,长径比为1200-1300,与AAO模板的参数一致.研究了Ni纳米线阵列的长径比对其磁性能的影响,发现大长径比的Ni纳米线阵列具有明显的磁各向异性,而长径比约为200的Ni纳米线阵列未表现出明显的磁各向异性.本文结果表明,恒电流二次氧化方法能制备大长径比的AAO模板,并能用于制备大长径比的一维纳米材料阵列,可望在制备具有特殊光学、磁学等性能材料方面得到应用.     

Pt纳米线阵列的氧还原催化性能

采用阳极氧化铝(AAO)模板法电化学沉积制备了Pt纳米线阵列(Pt NWs)氧还原催化剂, 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电化学测试对Pt纳米线阵列催化剂的形貌和电催化性能进行了表征. 循环伏安法(CV)研究表明Pt纳米线阵列催化剂的电化学活性面积大于其几何面积; 旋转圆盘电极(RDE)测试研究发现, 制备的Pt纳米线阵列催化剂的氧还原反应(ORR)曲线的半波电势相对Pt/C的有正移, 并且Pt纳米线阵列催化剂的极限扩散电流比Pt/C大.     

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.     

泡沫镍负载的NiCo2O4纳米线阵列电极的超级电容性能

采用无模板自然生长法制备了泡沫镍支撑的NiCo₂O₄纳米线阵列电极, 利用扫描电镜(SEM)和透射电镜(TEM)观测了纳米线的表面形貌, 利用X射线衍射(XRD)分析了纳米线的结构, 通过循环伏安、恒流充放电和交流阻抗测试了电极的超级电容性能. 结果表明: NiCo₂O₄纳米线直径约为500-1000 nm、长度约为10 μm, 垂直且密集地生长在泡沫镍骨架上. 纳米线阵列电极的放电比容量高达741 F·g^-1, 循环420次后比容量仍保持在655 F·g^-1, 电化学阻抗测试其电荷传递电阻仅为0.33 Ω, 420次循环后电荷传递电阻仅增加0.06 Ω.     

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.     

一种新的电化学方法制备CdS纳米线阵列

用一种新的电化学方法在多孔氧化铝模板中制备了CdS纳米线阵列体系,并用XRD、TEM对样品进行表征,结果显示CdS纳米线为立方相和六方相的多晶混合结构,对沉积机理进行了讨论.荧光光谱测量显示CdS纳米线阵列体系有三个强的紫外发光带和一个黄绿发光带.该文所使用的方法可以用来在氧化铝模板中制备其它材料的纳米线阵列体系.     

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。     

Effective deposition potential induced size-dependent orientation growth of Bi-Sb alloy nanowire arrays

The influence of effective deposition potential on the orientation and diameter of Bi(1-x)Sbx alloy nanowire arrays by pulsed electrodeposition technique was reported. X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy analysis show that the orientation of the Bi(1-x)Sbx nanowires can be turned from the [110] to the [202] direction by increasing the effective deposition potential, and the nanowires fully fill in the pores of the AAM in the lower potential region, while in the higher potential region the nanowires partly fill the pores of the AAM. The origin of those phenomena and the growth mechanism of the nanowire are discussed together with composition analysis.     

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.     

Highly ordered MnO2 nanowire array thin films on Ti/Si substrate as an electrode for electrochemical capacitor

AAO/Ti/Si substrate was successfully synthesized by a two-step electrochemical anodization of the aluminum film on the Ti/Si substrate and then used as template to grow nanowire arrays. The ordered MnO₂ nanowire arrays with about 40 nm diameters had been directly fabricated on AAO/Ti/Si substrate by direct current (DC) electrodeposition. The microstructure of the nanowire arrays was investigated by field-emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Their electrochemical characterization was performed using cyclic voltammetry in 0.5 M Na₂SO₄ aqueous solution. The synthesized MnO₂ nanowires had amorphous nature until 400 °C. The deal capacitive behavior was obtained when the as-prepared sample was heat-treated at 200 °C. The specific capacitance of the electrode was about 254 F/g.     

Synthesis of ordered Al nanowire arrays

Ordered Al nanowire arrays with the same nanowire density but the diameters decrease radially embedded in one piece of anodic alumina membranes were successfully fabricated by two-step synthesis: electrodeposition of Zn and replacement in AlCl₃ solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected-area electron diffraction techniques were used to characterize the Al nanowires obtained. SEM and TEM images taken from the different areas of Al nanowire arrays show that we can control the growth of aligned Al nanowires with different diameters in a single process at the same time. The investigation results not only have potential applications in photoelectric devices but also open up a new method for fabricating nano-scale materials.     

Epitaxial Growth and Thermoelectric Measurement of Bi2Te3/Sb Superlattice Nanowires

Superlattice nanowires are expected to show further enhanced thermoelectric performance compared with conventional nanowires or superlattice thin films. We report the epitaxial growth of high density Bi₂Te₃/Sb superlattice nanowire arrays with a very small bilayer thickness by pulse electrodeposition. Transmission electron microscopy, selected area electron diffraction and high resolution transmission electron microscopy were used to characterize the superlattice nanowires, and Harman technique was employed to measure the figure of merit (ZT) of the superlattice nanowire array in high vacuum condition. The superlattice nanowire arrays exhibit a ZT of 0.15 at 330 K, and a temperature difference of about 6.6 K can be realized across the nanowire arrays.