硒纳米线的合成及表征

采用对环境友好的绿色合成方法,在碱性条件下,利用氧化还原体系把高价硒还原成灰黑色的三方相硒.以蔗糖、葡聚糖为软模板和形态导向剂,制备出了尺寸均匀、形态不同的硒纳米线.并用XRD、SEM等分析手段对产物的形貌和结构进行了表征,并对它们的成线机理做了相应的分析和解释.结果表明,两种不同的糖对硒纳米线生长的影响不同,在蔗糖条...     

化学还原法合成均匀银纳米线的条件研究

采用化学还原法,以乙二醇为还原剂,聚乙烯砒咯烷酮(PVP K30)为表面活性剂,通过还原硝酸银(AgNO3)溶液直接制备了高浓度的Ag纳米线溶液,并研究了PVP与AgNO3溶液摩尔浓度比和AgNO3溶液浓度对Ag纳米线生长的影响.用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对纳米Ag晶体的生长形貌进行了比较,利...     

银纳米线的溶剂热合成与表征

以聚乙烯吡咯烷酮(PVP)为表面活性剂、乙二醇为溶剂,通过简易的溶剂热方法合成了银纳米线.结果表明,在反应体系中乙二醇不仅能作为溶剂,而且还能起到还原剂的作用.用XRD、SEM对产物进行了表征.考察了乙二醇和PVP用量等对银纳米线合成的影响;找出了合成的较佳条件.对银纳米线的合成机理进行了初步探讨.     

合成和表征NiFe2O4纳米线阵列

采用真空灌注结合溶胶-凝胶和氧化铝模板法,在多孔氧化铝模板中制备了平均直径为50 nm的NiFe2O4纳米线阵列.X射线衍射结果显示所制备的纳米线是纯相的NiFe2O4纳米线,透射电镜和电子衍射的结果显示已制备的纳米线是多晶的且表面光滑,场发射扫描电镜图片显示纳米线是大面积且平行有序的、纳米线的长度和所用的氧化铝模板的厚度相当.磁测量的结果显示此纳米线阵列有形状各向异性,同块状材料相比矫顽力有所增强.对纳米线的生长机理做了简单的讨论.     

纳米线研究进展（2）：纳米线的表征与性能（续上期）

本文纵纳米线的制备与生长机制,表征、性能和应用几方面综述了纳米线的最新进展,着重阐述了激光烧蚀法和模板法制备纳米线的过程及各自的生长机制。对纳米线的电、光、磁性能、及其潜在应用前景作了介绍。     

金纳米线的制备及其应用

金纳米线以其独特的光学和电学性质，在光学、电学、磁学等领域有着不可忽视的潜力，它的成功制备对于实现纳米尺度功能组件的实用化意义重大。介绍了金纳米线的合成方法及其应用，展望了未来的研究方向和发展趋势。     

纳米线研究进展

一维纳米结构如纳米线和纳米管,不仅在基础理论研究方面对于探索材料的维数和尺寸对其光学、电学和力学等性质的影响有很大的研究价值,而且其实际应用涉及领域十分广泛,如探针显微镜的针尖,纳米电子器件的连接等.本文评述纳米线研究的最新进展,着重介绍了不同类型纳米线的合成制备方法及其可能的应用领域,并对纳米线的研究趋势作了展望.     

立方相MgZnO纳米线的制备和表征

利用热蒸发方法,在硅衬底上制备出立方MgZnO纳米线。以Mg粉为源材料,所制备的为立方相MgO纳米线。以Mg粉和Zn粉混合物为源材料,可以制备出立方相MgZnO纳米线,Zn含量7%,直径200～300nm,具有单晶结构;同时产物中还包括六方相ZnO纳米线,直径30nm左右。MgZnO纳米线中Zn含量远低于源材料中的Zn含量,这可能是ZnO和Zn的蒸汽压远大于MgO和Mg的缘故。     

碳纳米管/ZnS复合材料的制备及其性能表征

碳纳米管用氨水、乙二胺四乙酸(EDTA)进行表面改性, 然后通过硫代乙酰胺、醋酸锌、水和表面改性的碳纳米管在水浴超声条件下发生溶液化学反应, 在碳纳米管表面包裹了一层分布均匀、致密的ZnS纳米晶粒. 用XRD、TEM、SAED、SEM、FTIR、PL等表征手段对材料进行了结构及性能表征. 研究结果表明: 对碳纳米管进行乙二胺四乙酸处理是实现ZnS纳米晶粒在碳纳米管表面均匀、致密包裹的重要因素, 碳纳米管/ZnS复合材料的光致发光性较之相同方法合成的ZnS, 俘获态发射峰蓝移6nm, 而能带边缘发射峰蓝移16nm. 通过对FTIR及不同表面改性碳纳米管的对比试验研究, 给出了碳纳米管/ZnS复合材料的形成机理.     

沉淀法制备ZnS∶Cr纳米晶及其光学性能研究

以十二烷基苯磺酸钠和六偏磷酸钠作为分散剂,采用沉淀法制备了ZnS及不同掺杂浓度的ZnS∶Cr纳米晶。利用XRD和TEM对纳米晶物相和形貌进行了分析。结果表明,ZnS和ZnS∶Cr纳米晶均为立方闪锌矿结构,利用谢乐公式估算ZnS和ZnS∶Cr纳米晶平均粒径分别为2.1和2.2nm。TEM观察到纳米晶近似为球形,平均粒度为3nm左右,具有较好的单分散性且分布均匀。荧光光谱(PL)表明,纳米晶在420、440和495nm处有发射谱带,前两者被认为是S空位深陷阱发光,后者被认为是表面态或中心辐射复合发光。     

Low temperature synthesis and optical property of ZnS nanotubes

Zinc sulphide (ZnS) nanotubes were synthesised via simple surfactant emulsion template under hydrothermal conditions. X-ray diffraction, scanning electron microscopy and transmission electron microscope were used to characterise the nanotubes. The results indicate that the nanotubes are composed of nanoparticles. The diameters of the nanotubes vary from 300 to 700?nm and lengths range from 1 to 2?µm. In addition, it is found that the reaction time, reaction temperature and cetyltrimethylammonium bromide play key roles in the phase and morphology control of ZnS nanotubes. Furthermore, room temperature photoluminescence was recorded to investigate the optical property of the obtained product. The stable and strong green emission band centred at 513?nm was attributed to some self-activated centres, probably vacancy states or interstitial states related to the peculiar structure.     

SnO_2纳米线的合成与结构表征

采用化学气相沉积法在经表面活性剂与硝酸镍的混合溶液处理过的硅衬底上成功制备出了直径均匀可控的二氧化锡(SnO2)纳米线。利用扫描电子显微镜、透射电子显微镜、选区电子衍射、X射线衍射等手段对样品的表面形貌、微结构及成分等进行了表征分析。并在此基础上讨论了纳米线所遵循的生长机理。     

Electrodeposition of nickel nanowires and nanotubes using various templates

Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm^?2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial growth direction is favoured yielding nanowires rather than nanotubes. However, for smaller pore size polycarbonate membranes, nanowires are obtained even though effective current densities were higher. We believe that when the pore diameter is below a critical size, nanowires grow regardless of current density since narrow pores promote layer by layer growth of nanorods due to smaller surface area of the pore bottom compared to pore walls. Pore size has a dominant effect over effective current density in determining the structure of the fibres produced for small pores. Nickel nanowires are also obtained in the small pores of anodised alumina, which has higher aspect ratios. High aspect ratio membranes favour the fabrication of nanowires regardless of current density.     

水热法制备Sb_2Te_3纳米线及其性能表征

在450K,pH值为11的条件下,以SbCl3,和Na2TeO3粉体为原料,用水热法制备了Sb2Te3纳米线。X-射线衍射(XRD)分析表明,所制的的材料为Sb2Te3,透射电镜(TEM)观察到Sb2Te3纳米线直径约为20nm,长度在200~600nm之间,并且自然平行密排成六边形纳米片状;然而在450K,pH值为13的条件下,制备出的产物则为完整的纳米片。扫描电镜(TEM)分析发现纳米线延(015)方向生长。差热测试得到Sb2Te3纳米线的熔点为727.5K。红外光谱的进一步研究表明,由Sb2Te3纳米线编织成的纳米片结构要优于整体生长成的纳米片,并就Sb2Te3纳米线的生长机理进行了初步推测。     

Synthesis and characterization of shaped ZnS nanocrystals in water in oil microemulsions

Shaped zinc sulfide nanocrystals were synthesized in W/O microemulsions by using cyclohexane/Triton X-100/n-pentanol/water system. Under different synthetic conditions appearance of two distinct morphologies of ZnS nanocrystals, either cubes or nanowires, was proven by transmission electron microscopy (TEM). The ZnS cubes have an average size of about 25 nm, while the ZnS nanowires have 25 Å diameter and length ranging from several hundred nanometers up to a few microns. The X-ray diffraction analysis (XRD) revealed formation of ZnS with cubic zinc blende crystal structure. Due to two dimensional confinement the exciton of ZnS nanowires is blue shifted compared to the bulk material. Four well-resolved photoluminescence bands in visible spectral region were observed upon excitation of cubic ZnS particles, while in the case of ZnS nanowires emission band was observed at 421 nm. The origin of photoluminescence bands was discussed in details.     

基于大分子配体修饰的Cd2+、Mn2+掺杂功能化ZnS纳米晶的制备与表征

以醋酸锌、氯化镉、醋酸锰和硫化钠为原料,采用末端带双键的聚甲基丙烯酸(PMAA)大分子单体为配体,在水溶液中成功制备出分散均匀并具有良好荧光性的Cd2+和Mn2+掺杂复合的ZnS纳米晶.利用电导率分析、TGA、Uv-vis、荧光光谱(PL)等表征手段考察了复合纳米晶结构和光学性能的关系.结果表明,PMAA中的大量羧基是以配位键的形式和纳米晶表面金属原子相结合.通过改变掺入的Cd2+的含量,能够获得从紫外光到可见光范围的ZnS:Cd2+复合纳米晶材料.     

Synthesis and characterization of ZnS nanowires by AOT micelle-template inducing reaction

ZnS nanowires, with diameters around 30 nm and lengths up to 2.5 μm, had been successfully synthesized from solutions containing an anionic surfactant, sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Powder X-ray diffraction (XRD) pattern, energy-dispersive X-ray spectroscopy (EDS) and selected-area electron diffraction (SAED) pattern indicated that the product was pure polycrystalline cubic-phase β-ZnS. The morphology and size of the as-synthesized product were determined by the transmission electron microscopy (TEM). The effects of some of the key reaction parameters (such as the ratio of surfactant to water, the reactant concentration and reaction temperature, etc.) had been explored in this paper. A growth mechanism of ZnS nanowires by micelle-template inducing reaction was also proposed.