氧化锌纳米线/管阵列的溶胶-凝胶模板法制备与表征

用溶胶-凝胶法在氧化铝模板中制备了直径约为15、30、50、60nm的有序氧化锌纳米线/管阵列.用扫描电镜(SEM)、透射电镜(TEM)和X射线衍射仪(XRD)对氧化锌纳米线/管的形貌、结构以及相组成进行了分析.结果发现,纳米线的形貌依赖于氧化铝模板中孔洞的形貌,纳米线的长度受控于氧化铝模板的厚度,外径与氧化铝模板的孔径相等.通过控制溶胶的浓度以及氧化铝模板在溶胶中的浸泡时间可以制备出纳米管.     

磁控溅射制备Ni亚微米管阵列及微结构研究

以阳极氧化铝(AAO)为模板,利用磁控溅射法制备了Ni亚微米管阵列。通过X射线衍射仪(XRD)、原子力显微镜(AFM)、扫描电子显微镜(SEM)等手段对沉积态以及经过400℃退火保温不同时间制备的Ni亚微米管阵列的物相结构及微观形貌进行了表征。结果表明：磁控溅射法制备的Ni亚微米管阵列具有多晶的面心立方结构。随着退火时间的增加,Ni亚微米管逐渐增多,Ni衍射峰强度逐渐降低。经400℃退火3h后,获得结构完整、高度有序的Ni亚微米管阵列,Ni亚微米管的大小均匀,外径约为400nm,内径约为200nm,长度约为500nm。     

溶胶-凝胶模板法制备K_(0.5)Na_(0.5)NbO_3纳米管阵列及其表征

以乙醇铌、乙酸钾和乙酸钠为原料,乙二醇甲醚为溶剂,采用溶胶-凝胶(Sol-Gel)阳极氧化铝(AAO)模板法制备了K0.5Na0.5NbO3(KNN)纳米管阵列.利用热分析确定晶化温度,采用X射线衍射、扫描电子显微镜和透射电子显微镜表征KNN纳米管的物相、形貌和微观结构.结果表明,KNN最佳的晶化温度为700℃;KNN纳米管阵列结晶性良好,为单斜钙钛矿多晶结构,单根纳米管的外径约为200nm,管壁厚约为20nm.对KNN纳米管阵列的铁电性能表征显示,其剩余极化率Pr约为1.86μC/cm2,矫顽场Ec约为0.68kV/cm。     

模板渗透法制备氧化锌纳米管阵列

采用溶胶-凝胶法,以醋酸锌和氢氧化锂为主要原料制备了纳米氧化锌溶胶;再以其为构造单元在阳极氧化铝模板(AAO)中通过减压渗透法制备了氧化锌纳米管阵列.同时利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)和能谱(EDS)对所得的氧化锌纳米颗粒、纳米管进行了分析.结果表明,所得的氧化锌纳米颗粒,粒径为2～5nm,分布较窄,属于纤锌矿型六方晶系;所得氧化锌纳米管,阵列结构规整,外径约为300nm,壁厚约为50nm,长度可以达到5μm以上.     

Ni纳米管阵列的选择性刻蚀法制备及磁性质

采用基于氧化铝模板的电化学共沉积方法合成了Ni/Cu纳米电缆有序阵列,通过电化学选择刻蚀纳米电缆的铜核,制备了多晶Ni纳米管有序阵列。Ni纳米管有序阵列表现出明显的单轴磁各向异性,易磁化轴沿着纳米管方向。这种具有磁各向异性的有序阵列在高密度垂直磁记录材料中具有潜在的应用前景。     

模板浸润法制备聚苯乙烯纳米管阵列

采用一种简单的物理技术——聚合物溶液或熔体浸润多孔阳极氧化铝(AAO)模板的方法,在孔径仅为200nm的AAO模板中制备聚苯乙烯(PS)纳米管阵列。SEM和TEM测试结果表明：熔体法制备的纳米管壁厚约为110nm;5．0wt％和10．0wt％的PS溶液制备的纳米管壁厚分别为70nm和80nm。并初步探索了模板法制备聚合物纳米管的多次浸润机理。     

镍纳米管阵列的电沉积合成及其磁学性能表征

以氧化铝膜为模板、金属汞为电阴极,采用简单的直流电沉积方法制备出高度有序的镍纳米管阵列。利用扫描电子显微镜、透射电子显微镜、选区电子衍射、能谱仪、X射线粉末衍射和样品振动磁强计对样品进行形貌表征、成分及磁性能分析。结果表明,阵列中的镍纳米管彼此平行,尺寸均匀,纳米管外径为260～360nm;镍纳米管阵列表现出良好的磁各向异性,其易磁化方向垂直于镍纳米管阵列。以金属汞为电阴极是易形成纳米管的关键条件。     

大规模制备Ni纳米线阵列及其磁学特性研究

在多孔氧化铝模板的纳米孔洞中,利用直流电化学沉积的方法成功地制备了高度有序的磁性金属Ni纳米线阵列.利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)和物理性质测量系统(PPMS)对样品的形貌、晶体结构和磁学性能进行了表征测试.SEM和TEM观察结果显示,Ni纳米线均匀地生长在氧化铝模板的孔洞中,直径约为300nm,其表面非常光滑.XRD结果显示,生长的Ni纳米线为fcc结构.磁测量结果表明,与体材料相比,Ni纳米线展现出增强的矫顽力和剩磁比,并且表现出较强的磁各向异性,其居里温度约为627K,与块体Ni的居里温度相当,说明在较高温度下,纳米线仍可呈现铁磁特性.     

溶液浸润法制备PS纳米管及其形成机理的初探

首次以孔径仅有200nm的阳极氧化铝(AAO)为模板，采用聚合物溶液浸润模板的物理技术，通过不同方法成功制备了常规分子量的PS纳米管及其阵列结构。SEM和TEM测试结果表明，有效地调整和控制制备方法和工艺，可制备出不同管壁厚度的聚合物纳米管．也可制备出管壁带有多孔的纳米管，还可制备出纳米线。探索了多孔模板法制备聚合物纳米管的机理。     

草酸溶液中制备大孔间距的通孔PAA模板

为了制备规则有序、大孔间距的多孔阳极氧化铝(PAA)模板,通过在传统的草酸溶液中添加乙醇以及阶梯升压的方法,使草酸溶液的耐压从原来的40V左右提高至150V,制备了大孔径(约200nm)、大孔间距(约350nm)的有序PAA模板。详细研究了这种高电压氧化得到的具有较厚阻挡层PAA模板的通孔工艺,实验结果表明,在5%(质量分数)磷酸水溶液中30℃下浸泡180min,可以得到有序的PAA通孔模板,首次计算了阻挡层的减薄速率为约1.26nm/min。     

A template-based electrochemical method for the synthesis of high dense nickel nanotube arrays

High dense Ni nanotube arrays have been successfully fabricated using electrochemical method with the assistance of anodic aluminum oxide (AAO) template from NiSO4 aqueous solution without any additive. Field emission scanning electron microscope (FE-SEM) results indicate that the pores of AAO template are high uniform and all the pores are filled with Ni nanotubes. Transmission electron microscope (TEM) results demonstrate that the diameter of Ni nanotubes is about 65 nm. The electron diffraction (ED) pattern results show that the Ni nanotubes are polycrystalline. X-ray diffraction (XRD) pattern shows that the electrodeposited nickel is hexagonal crystal structure.     

Fabrication, structural characterization and formation mechanism of multiferroic BiFeO3 nanotubes

Multiferroic BiFeO3 (BFO) nanotubes have been successfully fabricated by the modified sol-gel method within the nanochannels of porous anodic aluminum oxide (AAO) templates. The morphology, structure and composition of the nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected-area electron diffraction (SAED), high resolution TEM, (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). Postannealed (650 degrees C for 1 h), BFO nanotubes were polycrystalline and X-ray diffraction study revealed that they are of the rhomohedrally distorted perovskite crystal structure. The results of SEM and TEM revealed that BFO nanotubes possessed a uniform length (up to 60 microm) and diameter (about 200 nm), which were controlled by the thickness and the pore diameter of the applied AAO template, respectively and the thickness of the wall of the BFO nanotube was about 15 nm. Y-junctions in the BFO nanotubes were observed. EDX analysis demonstrated that stoichiometric BiFeO3 was formed. HRTEM analysis confirmed that the obtained BFO nanotubes made up of nanoparticles (3-6 nm). The possible formation mechanism of BFO nanotubes was discussed.     

End-closed NiCoFe-B nanotube arrays by electroless method

A novel approach is obtained during the fabrication of NiCoFe-B nanotube arrays via electroless method. Porous anodic aluminum oxide (AAO) templates fabricated by anodization of aluminum foil were sensitized using PdCl₂ solution and immersed into electroless plating baths at room temperature to produce nanotube arrays. Compositional and morphological properties of the nanotube arrays are characterized. Results indicates the formation of end-closed nanotubes with the dimension of 100-130 nm in outside diameter, which is determined by the pore size of the AAO template, and about 15 nm in thickness of tube walls. The possible formation mechanism of end-closed metallic nanotube arrays is discussed.     

Preparation of polyaniline nanotubes array based on anodic aluminum oxide template

In this article, the highly ordered polyaniline (PANI) nanotubes array was prepared by in situ polymerization using anodic aluminum oxide (AAO) as template. Polymerization of aniline was confined in the one-dimensional nanochannel of AAO template. The aniline was adsorbed and polymerized preferentially on the pore walls of template. The structure of PANI nanotubes array was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED) and dynamic force microscope (DFM). The results show that PANI nanotubes are synthesized successfully in the nanopores of template, the diameter and length of PANI nanotubes are closed to the pore diameter and thickness of AAO template, respectively, the arrangement of PANI nanotubes is very regular and uniform, the crystal form of PANI nanotubes is hexagonal, different from pseudo-orthorhombic crystal form of PANI bulk sample, and cell parameters a and b are 0.5008 nm. The change of crystal form is due to the confinement of AAO template, which makes the molecular chain of PANI arrange more ordered.     

简单蚀刻法制备具有可控高度的金属纳米线阵列

采用多孔阳极氧化铝(AAO)作为模板,运用电化学沉积法在模板的微孔中组装金属Ni纳米线,然后用磷铬酸蚀刻表层AAO模板,暴露出规整有序、具有可控长度的Ni纳米线阵列.分别用SEM、TEM与SAED对Ni纳米线阵列进行了表征.研究了蚀刻时间与AAO模板质量的减少及暴露出来的Ni纳米线阵列长度之间的关系.结果表明,磷铬酸是较NaOH溶液更为温和有效的AAO模板蚀刻剂,通过控制模板溶解时间,可以实现对裸露于AAO模板外纳米线长度的精细有效控制.该蚀刻方法普遍适用于以AAO为模板所制得的准一维纳米阵列结构.     

Template-based synthesis and magnetic properties of Ni nanotube arrays with different diameters

Ni nanotube arrays with different diameters were fabricated in the pores of the porous anodic alumina membranes by direct current electrodeposition. The crystal structure and micrograph of Ni nanotube arrays were characterized by X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. The results indicate that Ni nanotubes have no preferred orientation and are polycrystalline structure. The magnetic behaviors of Ni nanotube arrays with different diameters are investigated, and the coercivity of Ni nanotubes depends strongly on their diameters. The size-dependent behavior of the coercivity is qualitatively explained in terms of localized magnetization reversal.     

Novel fabrication of silica nanotubes using multi-walled carbon nanotubes as template

Silica nanotubes were synthesized using multi-walled carbon nanotubes (MWCNTs) as template. The as-obtained samples were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM) and photoluminescent (PL) spectroscopy. The results indicate that the thickness of the outer walls is about 10 nm and the inner diameter is completely dependent on the size of MWCNTs. The as-fabricated silica nanotubes emit a strong violet light under excitation of 250 nm.     

原位合成TiO2纳米管阵列及其光催化性能研究

采用液相沉积法(LPD), 以阳极氧化铝(AAO)为模板, 原位合成高度有序的TiO₂纳米管薄膜材料. 实验结果表明, 经过400℃热处理后, 制备的TiO₂纳米管为锐钛矿相, 长度达5μm, 管外径为150nm左右, 管壁厚为25nm左右. 热处理后的TiO₂薄膜具有良好的光催化降解甲基蓝的性能, 即经过120min卤灯照射后, 甲基蓝被完全降解.