有序锥形孔氧化铝模板的制备及其表征分析

阳极氧化铝(AAO)模板具有高度有序的纳米孔阵列,在制备一维纳米材料方面有广泛的应用,阳极氧化铝模板法是制备纳米线及纳米管的重要方法。文章基于二次阳极氧化的方法实验制备了柱面氧化铝模板,围绕氧化铝模板纳米孔径的大小和有序性,利用扫描电子显微镜(SEM)对所形成纳米孔的形貌特征进行观测,并与平面阳极氧化铝模板的纳米孔进行比较,分析了氧化铝模板表面纳米孔的生长情况及其形成机理。结果表明:高度有序的锥形纳米孔阵列会沿着柱面直径辐射生长;纳米孔没有出现弯曲和分叉现象,柱面AAO模板内外表面纳米孔径大小分别为40和55 nm;纳米孔径变化率为0.5 nm/μm,膜厚约为30μm,通过调整柱面铝片的曲率半径和阳极氧化时间,可以控制锥形纳米孔径大小范围在60~120 nm之间。     

多孔有序阳极氧化铝膜的制备及其机理分析

以草酸为电解液,利用电化学阳极氧化法制备多孔有序阳极氧化铝阵列模板,用透射电镜对其形貌和结构进行表征在此基础上,对多孔有序阳极氧化铝阵列模板的生长过程和形成机理进行了分析.结果表明,经阳极氧化处理后的铝片明显分成了未反应的铝、阻挡层氧化铝和多孔氧化铝3层结构,且阻挡层位于未反应铝和多孔层之间.多孔有序阳极氧化铝膜的形成更符合"电场支持下的溶解"模型.     

CoPt合金纳米有序阵列的制备及磁学特性

采用电化学沉积法,在氧化铝模板中制备了φ50 nm的CoPt合金纳米线的高度有序阵列.纳米线结构和磁学特性分别用透射电子显微镜、扫描电子显微镜、X射线衍射仪和振动样品磁力计测试.结果表明,CoPt合金纳米线以fcc结构存在.当外加磁场与纳米线线轴平行时,测得的矫顽力为192 Ka/m,剩磁比为0.75;当外加磁场与纳米线线轴垂直时,所测得的矫顽力仅为48 Ka/m,剩磁比为0.25.表明纳米线阵列具有明显的各向异性,纳米线的易轴方向为其线轴方向.     

铂纳米线阵列电极对肼的电催化性能

以阳极氧化铝为模板,采用直流电沉积法制备了铂纳米线阵列电极。用扫描电子显微镜,X射线衍射等手段对铂纳米线阵列电极的形貌与结构进行了表征,同时应用循环伏安法和计时电流法测试研究了其对肼的电催化氧化性能.结果表明,铂能够在氧化铝模板孔洞中完整地沉积生长,且纳米线直径与氧化铝模板孔径一致,约为50 nm;铂纳米线阵列电极对肼有明显的电催化活性,且其催化活性与肼浓度及扫描速率有关,肼浓度越大,催化活性越高,当肼浓度为50 mmol/L时,电流密度可达48 mA/cm2,约是铂柱电极的3倍;扫描速率越快,电流密度越大,且与峰电流密度的平方根成正比.铂纳米线阵列电极对肼也具有良好的催化稳定性和耐受性.     

电化学模板法制备Pt-WO3纳米线有序阵列

通过恒电势共沉积的方法,用银作为导电基底的多孔阳极氧化铝膜(Al2O3／Ag)为模板制备了Pt-WO3纳米线有序阵列。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和能量色散X射线分析(EDAX)对纳米线进行了表征。结果表明,纳米线呈直立状态,直径约为30nm,纳米线中Pt和w的质量比为m(Pt)：m(w)=19．6：1,原子的量比为,n(Pt)：n(W)=18．5：1。这种Pt-WO3纳米线有序阵列具有很大的比表面积,可用于有机小分子的电催化氧化。     

阳极氧化工艺对氧化铝模板孔径的影响

为了能制备出有序的纳米线阵列，采用一次阳极氧化的方法，制备出了孔径在12．8～43．5nm之间的多孔有序的氧化铝模板．通过改变氧化液浓度、氧化电压、氧化温度等条件，可对氧化铝模板的孔径大小进行控制，对各阳极氧化工艺因数对模板孔径的影响机理也进行了分析讨论．结果表明，在较低的氧化液浓度，氧化电压和氧化温度条件下，氧化铝膜的孔径较小；而在高的氧化液浓度，氧化电压和氧化温度条件下，氧化铝膜的孔径较大．     

氧化铝阵列模板的制备及表征

采用了目前较流行的制备模板的方法,将预处理过的铝箔采用二步阳极氧化法分别在硫酸和草酸电解液中制备AAO膜,压差(VRS)法剥离铝基体后,得到了孔径大小基本一致、有序度较高的氧化铝模板.用透射电子显微镜对多孔氧化铝阵列模板进行表征分析,讨论阳极氧化电压与氧化时间对AAO孔膜形态的影响.     

电化学沉积并氧化法制备CoFe2O4纳米线阵列

用阳极氧化铝(AAO)模板,通过电化学沉积并氧化制备得到纳米线阵列.X射线衍射(XRD)结果显示纳米线由立方尖晶石CoFe2O4相构成,且无明显的择优取向.从透射电子显微镜(TEM)照片可看出,(AAO)模板内刚刚沉积的CoFe2纳米线结构疏松,而通过在空气气氛下的热处理,疏松的CoFe2纳米线转化为致密的CoFe2O4纳米线.当扩孔时间为40 min时,纳米线阵列的矫顽力最大,为1.9 kOe(外磁场平行于纳米线).进一步增加扩孔时间,矫顽力将下降.当外场垂直纳米线时,矫顽力随着扩孔时间的增加而单调减少.外场平行纳米线时,退磁曲线的方形度随着扩孔时间的增加而单调地从0.48减少到0.42;而外场平行纳米线时,方形度却从0.48增加到0.52.     

垂直Cu2ZnSnS4纳米线太阳能电池吸收层的研究与制备

采用两步电化学沉积法制备了CZTS薄膜和CZTS纳米线阵列,对450～650℃硫化温度下的CZTS薄膜的形貌和物相结构进行了分析,结果表明:在550℃硫化条件下可以获得锌黄锡矿相的CZTS.以阳极氧化铝(AAO)作为模板,采用了"先硫化,后移除AAO模板"和"先移除AAO模板,后硫化"两种方式对Cu-Zn-Sn预制层进行处理,得到了垂直形貌的CZTS纳米线,保证了纳米线的完整性和较好的垂直度.在0.2～2μm入射光波范围,与CZTS薄膜相比,CZTS纳米线平均反射率降低20％,展现了良好的减反射特性,有利于增大吸收层的吸收;同时也通过优化硫化工艺顺序为制备垂直的CZTS纳米线提供了新思路.     

（002）织构HCP钴纳米线磁性研究

采用交流电化学沉积法在氧化铝模板孔洞中制备了有序钴纳米线阵列。利用X射线衍射、扫描电子显微镜、透射电子显微镜、振动样品磁强计等对样品的结构、形貌和磁性进行了表征和研究。扫描电镜表明氧化铝模板孔洞直径为20 nm,结构研究证明钴纳米线为六角密堆积（HCP）结构且具有很强的（002）织构,磁性测试发现该钴纳米线阵列具有很强的单轴各向异性,室温矫顽力达2 590 Oe,有望用于高温永磁磁记录。     

氢敏感材料:钯镍合金纳米线条阵列的制备与性能

为了获得钯镍合金纳米线条优秀的氢敏感性能,采用不同方法获得不同形貌的钯镍合金纳米线条阵列.用AAO模板可以制得连续光滑的纳米线条,在石墨阶梯边上沉积可以得到纳米粒子链,在铂微电极上交流电沉积能够得到多孔纳米线条和枝晶状纳米线条.氢传感实验表明,钯镍合金纳米粒子链和多孔纳米线条结构具有高的氢敏感性和快速响应能力,因此应使用这2种钯镍合金纳米结构材料制备氢传感器才能获得更好的性能.     

Fabrication and photoluminescence property of CdS nanowire array by template electrodeposition

CdS nanowire arrays were synthesized by altering current（AC） electrodeposition in the porous anodic alumina film prepared by aluminium anodizing in oxalic acid. These nanowires have a uniform diameter of about 45 nm corresponding to the pore size of the films used and length up to several microns. The X-ray diffraction（XRD） pattern indicates that the CdS nanowires crystallize in an hcp structure. Besides, photoluminescences（PL） of CdS nanowire arrays, characterized by spectrophotometer show that CdS nanowries embedded in porous alumina template increases the light-emitting intensity and induces a red shift of PL band.     

Fabrication and Photoluminescence Property of CdS Nanowire Array by Template Eiectrodeposition

CdS nanowire arrays were synthesized by altering current(AC)electrodeposition in the porous anodic alumina film prepared by aluminium anodizing in oxalic acid.These nanowires have a uniform diameter of about 45 nm corresponding to the pore size of the films used and length up to several microns. The X-ray diffraction(XRD)pattern indicates that the CdS nanowires crystallize in an hcp structure.Besides, photoluminescences(PL)of CdS nanowire arrays,characterized by spectrophotometer show that CdS nanowries embedded in porous alumina template increases the light-emitting intensity and induces a red shift of PL band.     

Fabrication and characterization of highly ordered Ni0.5Zn0.5Fe2O4 nanowire/tube arrays by sol-gel template method

Highly ordered nanowire/tube arrays of Ni0.5Zn0.5Fe2O4 were fabricated by the sol-gel method in the pores of anodic alu- mina membrane (AAM). Whether nanowires or nanotubes were fabricated depends on immersion time. The immersion time was 15-40 s for nanotubes and over 60 s for nanowires. The topography and crystalline structure of the nanowire arrays were character- ized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). It was found that the length and diameter of the Ni0.5Zn0.5Fe2O4 nanowires are related to the thickness of the AAM and the diameter of the pores. The results indicated that the Ni0.5Zn0.5Fe2O4 nanowires are uniform and parallel to each other.     

Struetural and Magnetic Properties of Electrodeposited Ni70Fe30 Nanowire Array

Ordered Ni70Fe30 nanowire array was fabricated in a porous alumina template by altemating current electrodeDositiOn.The structural and magnetic properties of the as-obtained nanowire array were investigated by SEM,TEM,XRD,EDS and VSM.The results indicate that the as-obtained Ni70Fe30 nanowires exhibit a diameter of about 69.9 nm and aspect ratio of more than 60.Meanwhile,a preferred orientation[110]of bcc lattice was observed.The as-obtained nanowire array has an obvious magnetic anisotropy,of which the easy direction is perpendicular to the surface of the array.Moreover,after annealed,the Ni70Fe30 nanowire array exhibits an enhanced magnetic anisotropy.     

Preparation and characterization of highly ordered NiO nanowire arrays by sol-gel template method

Highly ordered nickel monoxide （NiO） nanowire arrays were fabricated by sol-gel synthesis within the pores of anodic alumina membrane （AAM）. Scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD） were used to characterize the topography and crystalloid structure of NiO nanowire arrays. The length and diameter of the NiO nanowires depended on the thickness of the AAM and the diameter of the pores. The results indicated that the NiO nanowires were uniformly assembled into the ordered nanopores of the AAM and paralleled to each other. Nickel monoxide nanotubes were also fabricated with the same method by changing the immersing time. This new method to prepare NiO nanowire arrays may be important from gas sensors to various engineering materials.     

Fabrication and green emission of ZnO nanowire arrays

Well-aligned single-crystalline wurzite zinc oxide (ZnO) nanowire arrays were successfully fabricated on a Si substrate by a simple physical vapor-deposition (PVD) method at a relatively low temperature of about 500℃. The as-fabricated nanowires were preferentially arranged along the [001] direction of ZnO. The photoluminescence spectrum of ZnO nanowire arrays showed two emission bands: a strong green emission at around 500 nm and a weak ultraviolet emission at 380 nm. The strong green light emission was re...     

AlN纳米线阵列的光学性质及第一原理计算

为了制备均匀的宏观AlN纳米线阵列,采用化学气相沉积法在二次模板上成功地合成了AlN纳米线宏观阵列.利用X射线衍射仪、扫描电子显微镜、电子能谱仪和紫外-可见光光度仪测试了AlN纳米线阵列的结构、形貌和紫外发光性能.结果表明,AlN纳米线阵列分布均匀,AlN纳米线的平均直径与平均长度分别约为41 nm和1. 8μm. AlN纳米线的分布密度约为5. 4×107mm-2,其覆盖率约为7. 1%. AlN纳米线在150～310 nm范围内具有很好的吸光性能.利用第一原理计算得到的AlN纳米线光学性质与实验结果相符.