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.     

Preparation and Optical Properties of V2O5 Nanotube Arrays

V2 O5 nanotube arrays in porous atomic alumina （ PAA ） template were obtained from V2O5 sols prepared by melt quenching method. X-ray powder diffraction and selected area electron diffraction investigations demonstrate that V2O5 nanotubes are orthorhombic. Results by scanning electron mieroscopy and transmission electron microscopy results shove that V2O5 nanotubes with a uniform diameter form highly ordered arrays. The diameter and length of the nanotubes depend on the pore diameter and the thickness of the PAA template used. It is proved that the sol-gel template process is a cost-saving , simple and readily-controlled method to prepare metal oxides nanomaterials .Owing to the quantum size effect. the optical absorption edge of V2O5 nanotubes in PAA ehibits a significant blue shift with respect to that of bulk V2O5.     

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.     

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.     

Preparation of long alumina fibers by sol-gel method using tartaric acid

Long alumina fibers were prepared by sol-gel method.The spinning sol was obtained by mixing aluminum nitrate,tartaric acid,and polyvinylpyrrolidone with a mass ratio of 10∶3∶1.5.Thermogravimetry-differential scanning calorimetry (TG-DSC),Fourier transform infrared (FT-IR) spectra,X-ray diffraction (XRD),and scanning electron microscopy (SEM) were used to characterize the properties of the gel and ceramic fibers.A little of α-Al2O3 phase is observed in the alumina precursor gel fibers sintered at 1273 K.The ...     

Structure and Magnetic Properties of Ni Nanowires Array Fabricated by Direct Current Electro-deposition in Anodic Alumina Membrane

Ordered nanostructure arrays of Ni-Al2O3 were synthesized by direct current electro-deposition in anodic alumina membranes ( AAM ) . The investigation with an electron microscope, an X- ray diffractmeter and a vibration sample magnetometer indicates that the Ni nanowires , growing in the pores of AAM with about 45 nm in diameter, are monocrystalline and have a definite preferred crystallizing orientation. The magnetic behavior of the arrays and their mechanism were discussed.     

溶胶-凝胶法Al2O3纳米粉体的制备及表征

以异丙醇铝(Al(C₃H₇O)₃)为原料,采用溶胶-凝胶法制备出了纳米Al₂O₃粉体.TGA DTA分析可知Al₂O₃干凝胶的晶型转变过程，XRD分析结果也表明，溶胶-凝胶法所获得的干凝胶在1 200 ℃的温度下可以完全转化为α-Al₂O₃纳米颗粒,所制备的纳米α-Al₂O₃具有较为理想的晶体结构类型,并未发现其它的相或杂质.透射电子显微镜(TEM)观察到热处理为450?℃时所制备的纳米Al₂O₃粉体是粒径大约在10 nm左右的非晶体，而经过1 200 ℃处理1 h后完全转变成α-Al₂O₃，其粒径范围在15～35 nm，并由此解释随着晶型的转变而产生粒子团聚的原因.     

溶胶-凝胶法制备TiO_2/MCM-41负载型光催化剂及其性能表征

以钛酸丁酯为钛源、MCM-41分子筛为载体,采用溶胶-凝胶法制备TiO2/MCM-41负载型光催化剂,并通过XRD、BET、TEM、XPS对最佳条件下制备的光催化剂进行表征。结果表明,所制光催化剂是一种具有均匀规则孔道结构的介孔材料,其粉体比表面积高达358.8m2/g;经700℃煅烧,催化剂主要晶相为锐钛矿相。光催化剂中的Ti以＋4价存在,TiO2表面羟基氧所占比率为38.0%。以水中甲基橙为模拟污染物,TiO2/MCM-41光催化剂对浓度为25mg/L的甲基橙溶液降解0.5h后,其脱色率为93.7%。     

基于溶胶凝胶法的TiO_2溶胶的制备

用N-N二甲基乙酰胺（DMAC）作溶剂,钛酸丁酯作前驱物,冰乙酸为稳定剂,通过溶胶凝胶法制得了二氧化钛（TiO2）溶胶,并且对加水方式、加水量、溶剂量、pH值、温度等影响因素进行了考察。结果表明,当采用分散加水方式,温度在25℃～35℃以下,DMAC与钛酸丁酯的体积比为3.5：1,V（H2O）/V（Ti（OC4H9）4）为2～3,pH值为2～4时所得TiO2溶胶稳定,透明性好,可用作聚合物与纳米二氧化钛复合膜的研制的添加剂。     

AAO模板上碳纳米棒定向膜的制备及摩擦性能分析

在多孔阳极氧化铝（AAO）模板上的有序纳米孔中电化学沉积过渡金属Co作为催化剂，通过催化化学气相沉积（CCVD）法制备出有序、均匀的非晶态碳纳米棒定向膜。采用扫描电子显微镜（SEM）、能谱仪（EDS）及激光Raman光谱等方法分析了非晶态碳纳米棒定向膜的微观结构和形貌，并讨论了其摩擦因数与载荷及速度的关系。实验结果表明，非晶态碳纳米棒定向膜具有较小的摩擦因数，并且随着载荷的增加而减小，随速度的增加而先减小后增大，当滑动速度为0.18 m/s时摩擦因数最小。     

溶胶—凝胶法制备硅灰石超细粉体

以正硅酸乙酯(TEOS)、硝酸钙[Ca(NO3)2·4H2O]为原料,采用溶胶 凝胶法制备了CaO SiO2干凝胶粉末。在适当的条件下制备粒径为0.2～1.0μm的硅灰石粉体。研究发现热处理温度、时间对粉体粒度有较大影响。采用DTA、XRD等研究了CaO SiO2凝胶粉末在热处理过程中的物理、化学变化及晶相转变,并通过TEM观察了干凝胶粉末热处理产物的形貌。     

溶胶-凝胶法制备硅灰石超细粉体

以正硅酸乙酯(TEOS)、硝酸钙[Ca(NO3)2·4H2O]为原料,采用溶胶 凝胶法制备了CaO SiO2干凝胶粉末。在适当的条件下制备粒径为0.2～1.0μm的硅灰石粉体。研究发现热处理温度、时间对粉体粒度有较大影响。采用DTA、XRD等研究了CaO SiO2凝胶粉末在热处理过程中的物理、化学变化及晶相转变,并通过TEM观察了干凝胶粉末热处理产物的形貌。     

溶胶凝胶法制备网状锰酸锂材料

以乙酸锰和乙酸锂为金属源,间苯二酚和甲醛为分散剂,柠檬酸为络合剂,采用溶胶凝胶法成功制备具有网状结构的锰酸锂粉体．通过XRD、SEM、TEM、循环伏安等测试手段对产物进行了表征,并探究了甲醛的加入量和体系PH对其晶相结构和形貌的影响．实验结果表明：制备的锰酸锂晶粒尺寸在几十个纳米左右,并且当甲醛的加入量为9mL、体系pH为8时,锰酸锂粉体表现出高的纯度、优异的结晶性能以及密集而巨大的面网结构．其循环伏安测试结果表明,其载流子传递、转移方面性能优良,可能因其结晶性能优良,本身所具有的独特的网络结构可以提供更多的嵌锂空间,并且缩短离子扩散路径．     

Preparation of copper nano-wires by template synthesis method

Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lower voltage.The morphologies of template and copper nano-wires arrays were characterized by means of field emission scanning electron microscope(FESEM) and the crystal structure of copper nano-wires was determined by means of X-ray diffraction. The results indicate that copper nano-wires hold the preferred crystalline orientation along (111), (200),(220) and (331) crystal faces during growth, and the growth of copper nano-wires in the nano-holes of the template is homogenous and continuous.     

CoFe2O4纳米线阵列的制备与性能表征

采用Sol-gel法在孔径分别为50nm和200nm的AAO模板中制备高度有序的CoFe2O4纳米线阵列。用SEM、TEM和HRTEM对纳米线阵列的形貌和结构进行了表征。对钴铁氧体纳米线阵列进行磁性能研究，结果表明，CoFe2O4纳米线阵列没有择优取向性，但直径为50nm的钴铁氧体纳米线阵列的矫顽力大于直径为200nm的钴铁氧体纳米线的矫顽力，这是由于AAO模板的纳米孔道对材料的限域效应引起的。     

Preparation and Characterization of Highly Oriented ZnO Film by Ultrasonic Assisted SILAR Method

Ultrasonic Assisted SILAR method （UA-SILAR） was developed and highly oriented ZnO films were deposited on the glass substrate by this novel technique. The crystallinity and microstructure of as-deposited ZnO films were analyzed by means of XRD and SEM. Moreover, the underling deposition mechanism of ZnO films was discussed. Results show that obtained ZnO films exhibit an excellent crystallinity with the preferentioal orientation of （002） plane. The crystalline grain of films is about 40nm in size,which is supported by both the Sherrer equation and the SEM result. However, the ZnO film is composed of numerous clustered purticulates in the size of 200 to 300nm, and each particulate is the compact aggregation of smaller ZnO crystalline grains. It is .speculated that the excellent crystallinity of ZnO films may chiefly originate from the cavatition effect of the ultrasonic rinsing process.     

Preparation of self-sustained film by sol-gel method

Large size self-sustained film with considerable thickness ranging from 30 to 500 μm was prepared with sol-gel method by using dimethyldiethoxysilane/tetraethoxysilane composite alkoxide as precursor. The film exhibits good plasticity as well. Various factors that may influence the film properties were investigated. IR and AFM techniques were adopted to study the film structure and surface morphology. Gas chromatogram/mass spectrum technique was also adopted to characterize the network structure of the material through identification of different polymers formed during hydrolysis and condensation course.     

溶胶凝胶法制备介孔五氧化二钽薄膜

以五氯化钽为反应前驱体,三嵌段两性聚合物P123做天然模板,用溶胶凝胶法制备出了介孔五氧化二钽薄膜．经过SEM检测分析,薄膜厚度约为200nm．XRD研究结果表明,制得的薄膜具有明显的介孔结构,经TEM检测可以观察到孔洞结构;得到的五氧化二钽薄膜经过400℃煅烧1h,介孔结构仍然得到保留．     

TiO2/NiO复合纳米纤维制备及光催化性能研究

通过溶胶一凝胶过程,采用静电纺丝技术,以聚乙烯吡略烷酮(PVP,Mn=900 000)和钛酸正丁酯为前驱物,制备了PVP/Ti(OPr)./Ni(CH3COO)2复合一维纳米纤维材料.经控温缓慢氧化分解,在600℃的条件下成功制备了直径50～100 nmTiO2/NiO纳米纤维.采用扫描电镜、红外光谱、X射线粉末衍射、拉曼等分析手段对样品进行了表征,系统地介绍了TiO2光催化作用机理并在紫外灯下使用样品对罗丹明B溶液进行降解实验.结果显示,0.5%TiO2/NiO复合纳米纤维具有良好的光催化活性.