SnO2纳米棒的制备及表征

在聚氧乙烯五醚（NP5）,聚氧乙烯九醚（NP9）,乳化剂（OP）和环己烷组成的微乳体系中制备二氧化锡前驱物.然后再经800～820℃焙烧2.5h,成功地制备了直径为30～90nm,长5～10μm的金红石结构的二氧化锡纳米棒,并用透射电子显微镜,电子衍射,X射线衍射对二氧化锡纳米棒的结构进行了表征.用熔盐合成机理对其形成进行了讨论,初步认为是成核、长大过程形成了二氧化锡纳米棒.     

氧化还原法制备SnO2纳米棒的研究

在聚氧乙烯五醚(NP5)、聚氧乙烯九醚(NP9)和环己烷组成的微乳体系中用氧化还原法制备SnO2前驱物,然后在熔盐中再经800℃、860℃焙烧2.5h,成功地制备了金红石结构的SnO2纳米棒,并用透射电子显微镜,X射线衍射对SnO2纳米棒的结构进行了表征.     

聚羧酸型梳状共聚物超分散剂的构性关系研究

以聚氧乙烯甲基烯丙基二醚（APEO－n)，顺丁烯二酸酐（MAn)，苯乙烯（St)等为共聚单体，合成了一系列聚羧酸型梳状共聚物，研究了共聚物的结构，组成等对分散性能的影响，结果表明，接枝链的长度和密度影响超分散剂的性能，当接枝链长度为20－60，St%(mol%)为5％－20％时，分散性能良好。     

Co-ZnO稀磁半导体纳米棒的水热合成研究

文章利用水热反应法制备出单晶结构的Co掺杂ZnO纳米棒，并对其形貌和结构进行表征。透射电子显微镜（TEM）结果表明，首先制备得到的纳米ZnO颗粒粒径分布窄，尺寸在50nm左右；用其作为生长Co-ZnO纳米棒的核而进一步反应得到的产物结晶完整，棒直径在40．70nm范围内，棒长一般在0．5μm左右，纳米棒沿着[001]方向生长。同时对反应中ZnO核以及PEG对纳米棒生长的影响进行了讨论。     

利用磁控溅射及热蒸发法制备SnO2纳米线及结构表征

以Sn为原料,采用磁控溅射及热蒸发法制得SnO2纳米线,用扫描电镜（SEM）、透射电镜（TEM）、X射线衍射（XRD）、能量弥散X射线谱（EDS）、傅氏转换红外线光谱分析（FTIR）、拉曼光谱分析（Raman）等测试手段对纳米结构进行表征,结果表明,合成的二氧化锡纳米结构具有金红石结构,二氧化锡纳米材料的生长机制遵循气一液一固生长机制,生长过程中的温度和退火时间对二氧化锡纳米结构的形貌起着极其重要的作用,可以通过这些因素对二氧化锡纳米材料实行可控生长。     

低温下ZnO花状微结构的合成和性质

在无表面活性剂的条件下，通过水热法在三种不同的基底上制备了由纳米棒组成的花状氧化锌微结构，其纳米棒沿c轴方向生长。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）对花状氧化锌微结构进行了表征。XRD测试结果表明ZnO为纤锌矿结构，扫描电镜照片表明ZnO微结构具有花状形貌。简单讨论了反应物浓度对花状ZnO纳米棒形成的影响及生长机理。     

空心超顺磁性Fe3O4纳米微球的制备与表征

利用聚氧乙烯-聚氧丙烯-聚氧乙烯嵌段共聚物F127作为模板采用共沉淀法制备了空心超顺磁性Fe3O4纳米微球并用X射线衍射(XRD)和透射电子显微镜(TEM)进行了表征，纳米微球的大小为55-75nm，壳的厚度为7nm左右，颗粒大小均匀、在水溶液中分散良好．     

聚苯乙烯/聚氧乙烯两亲微球的表征

利用聚氧乙烯大分子单体为功能单体，与苯乙烯悬浮共聚，合成具有两亲结构，平均微粒径在5μm-35μm的微球，用扫描电镜（SEM）对微球的形貌，粒径及粒径分布进行表征；聚合物的结构及组成分别用红外光谱和元素分析仪测定；微球表面及内层的聚氧乙烯含量根据X光电子能谱（XPS）测得的氧含量计算得到，结果表明聚氧乙烯在表面层的含量明显高于内层及平均值；用滴定法测定了微球中羟基的含量，改变反应条件，可合成羰基含量在0.05mmol/g-0.2mmol/g的两亲微球。     

水溶性PEO—PPO—PEO包裹Fe3O4纳米微粒的可控制备

以聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物（PEO—PPO—PEO）作表面活性剂,采用纳米微乳液法还原Fe（Ⅱ）-乙酰丙酮化合物（Fe^Ⅱ（acac）2）,制备粒径可控、单分散、水溶性Fe3O4纳米微粒,并进行了相关的表征测试。从傅里叶变换红外光谱（FTIR）中可以看出,共聚物PEO—PPO—PEO包裹在Fe3O4纳米微粒表面;透射电镜（TEM）显示纳米颗粒分散性好,呈球形;高斯拟合表明,不同物料配比合成的Fe3O4粒子大小、粒径分布不同;振动样品磁强计（VSM）测试说明,Fe3O4纳米颗粒室温下为超顺磁性或软铁磁性。由于PEO-PPO—PEO具有亲水性,PEO—PPO—PEO包裹的Fe3O4纳米微粒不用进一步处理即可转移到水相中,在生物和医学领域具有重要的潜在应用价值。     

一种制备SnO_2纳米棒的新工艺——纳米颗粒固相转化法

利用室温固相反应方法 ,合成了二氧化锡纳米颗粒前驱物(直径D≤10nm)。选择合适的熔盐介质KCl,在600～800℃对前驱物进行退火处理 ,前驱物纳米颗粒可自组装生长形成SnO2 纳米棒、纳米线。纳米棒直径为15nm ,长度从纳米级到微米级 ,其中可以观测到V型纳米结构 ,V型角度变化从锐角到钝角。分析了SnO2 纳米颗粒前驱体生长过程中熔盐介质、热处理温度和颗粒临界尺寸对纳米颗粒自组织生长的影响 ;探讨了SnO2 纳米颗粒固相生长现象。利用TEM和XRD对制备产物的形貌、成分进行了表征和分析     

焙烧室温条件固相反应制备前驱物合成SnO2纳米棒的研究

室温条件下通过固相反应合成了SnO2纳米颗粒前驱物.在600～780℃对前驱物进行焙烧,在NaCl、KCl和KCl＋NaCl的熔盐介质中SnO2前驱物纳米颗粒自组装生长形成SnO2 纳米棒.利用TEM、XRD和XPS对SnO2纳米棒结构、形貌和成分进行了研究.结果表明SnO2纳米棒直径为20～80nm,长度从几百纳米到十几微米.分析了SnO2 纳米颗粒前驱体熔盐介质中的生长,利用固相转变生长可以解释SnO2纳米棒在熔盐介质中的生长机制.     

Rutile structured SnO2 nanowires synthesized with metal catalyst by thermal evaporation method

One-dimensional (1-D) nanostructures such as tubes, rods, wires, and belts have attracted considerable research activities owing to their strong application potential as components for nanosize electronic or optoelectronic devices utilizing superior optical and electrical properties. Characterizing the mechanical properties of nanostructure is of great importance for their applications in electronics, optoelectronics, sensors, actuators. Wide-bandgap SnO2 semiconducting material (Eg = 3.6 eV at room temperature) is one of the attractive candidates for optoelectronic devices operating at room temperature, gas sensors, and transparent conducting electrodes. The synthesis and gas sensing properties of semiconducting SnO2 nanomaterials have became one of important research issues since the first synthesis of SnO2 nanobelts. Considering the important application of SnO2 in sensors, these structures are not only ideal systems for fundamental understanding at the nanoscale level, but they also have potential applications as nanoscale sensors, resonator, and transducers. The structured SnO2 nanorods have been grown on silicon substrates with Au catalytic layer by thermal evporation process over 800 degrees C. The resulting sample is characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDS). The morphology and structural properties of SnO2 nanowires were measured by scanning electron microscopy and high-resolution transmission electron microscopy. The mean diameter of the SnO2 nanorods grown on Au coated silicon (100) substrate is approximately 80 nm. In addition, X-ray diffraction measurements show that SnO2 nanorods have a rutile structure. The formation of SnO2 nanowires has been attributed to the vapor-liquid-solid (VLS) growth mechanisms depending on the processing conditions. We investigated the growth behavior of the SnO2 nanowires by variation of the growth conditions such as gas partial pressure and temperature.     

Needle-like Zn-doped SnO2 nanorods with enhanced photocatalytic and gas sensing properties

Zn-doped SnO(2) nanorods have been prepared by a simple hydrothermal method on a large scale. The as-prepared samples were characterized by x-ray powder diffraction, scanning electron microscope, transmission electron microscope, energy dispersive spectrometer, x-ray photoelectron spectroscopy, UV-vis absorption spectra and photoluminescence spectra. Studies found that the products are needle-like single-crystalline nanorods grown along the [[Formula: see text]] orientation. The photocatalytic properties of the synthesized Zn-doped SnO(2) were investigated by decomposing acid fuchsine, showing much higher photocatalytic activity than pure SnO(2) nanorods and bulk SnO(2) powders. An enhanced gas sensing ability toward methanal, ethanol and acetone gases is also achieved in high sensitivity and fast response. The origins of the enhanced performances are discussed.     

Preparation and characterization of MgO nanorods coated with SnO2

MgO nanorods have been grown by thermal evaporation of Mg3N2 powders on Si (100) substrates coated with gold (Au) thin films. The MgO nanorods grown on Al2O3 (0001) were 0.1-0.2 microm in diameter and up to a few tens of micrometers in length. MgO/SnO2 coaxial nanorods have also been prepared by atomic layer deposition (ALD) of SnO2 onto the nanorods. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis results indicate that the MgO-cores and the SnO2 shells of the annealed coaxial nanorods are of a single crystalline nature with cubic and orthorhombic structures, respectively. The photoluminescence (PL) spectroscopy analysis results show that SnO2 coating slightly increases the PL emission intensity of MgO nanorods. The PL emission of the SnO2-coated MgO nanorods is found to be considerably enhanced by thermal annealing and to strongly depend on the annealing atmosphere. The PL emission intensity of the MgO/SnO2 coaxial nanorods has been significantly increased by annealing in a reducing atmosphere. The origin of the PL enhancement by annealing in a reducing atmosphere is discussed on the basis of energy-dispersive X-ray spectroscopy analyses.     

Investigation of substrate influence on tin dioxide nanostructures synthesized using horizontal furnace

SnO2 nanostructures were directly synthesised by chemical vapour transport on different substrates in a horizontal furnace. The influence of substrate on the morphology of these nanostructures was investigated by changing the substrate type, coating, and temperature. The SnO2 nanowires and nanorods were one dimensional (1D) structures with widths and lengths of 50-200 nm and several micrometers respectively. Scanning electron microscope (SEM) images show formation of short nanorods with lengths of less than 1 microm on indium-tin oxide (ITO) substrates. The effect of substrate temperature on growth was studied. SnO2 nanowires were obtained using silicon substrate, and the effect of Au coating on the size and morphology of these structures was proposed. By coating the Si wafer with a thin layer of Au, the size of the nanostructure was reduced and the length increased. The differences in size and morphology are shown by transmission electron microscopy (TEM). X-ray diffraction (XRD) spectra show tetragonal structures for both substrates.     

Synthesis and optical properties of SnO(2) nanorods

Well-crystalline SnO(2) nanorods have been synthesized successfully via a lithium-assisted solution-phase method. The structural and optical properties of the SnO(2) nanorods were investigated using x-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and infrared, Raman and photoluminescence spectroscopy. The experimental results show that lithium addition plays a critical role in the formation of SnO(2) nanorods, and the correlation between the surface energy change and morphological evolution of this material is also discussed. This approach provides an economically viable route for large-scale synthesis of this nanostructured material.     

SnO2/WO3 core-shell nanorods and their high reversible capacity as lithium-ion battery anodes

WO(3) nanorods are uniformly coated with SnO(2) nanoparticles via a facile wet-chemical route. The reversible capacity of SnO(2)/WO(3) core-shell nanorods is 845.9 mA h g(-1), higher than that of bare WO(3) nanorods, SnO(2) nanostructures, and traditional theoretical results. Such behavior can be attributed to a novel mechanism by which nanostructured metallic tungsten makes extra Li(2)O (from SnO(2)) reversibly convert to Li(+). This mechanism is confirmed by x-ray diffraction results. Our results open a way for enhancing the reversible capacity of alloy-type metal oxide anode materials.     

The synthesis and selective gas sensing characteristics of SnO(2)/α-Fe(2)O(3) hierarchical nanostructures

SnO(2)/α-Fe(2)O(3) hierarchical nanostructures, in which the SnO(2) nanorods grow on the side surface of α-Fe(2)O(3) nanorods as multiple rows, were synthesized via a three-step process. The diameters and lengths of the SnO(2) nanorods are 6-15?nm and about 120?nm. The growth direction of SnO(2) nanorods is [001], significantly affected by that of α-Fe(2)O(3) nanorods. The hetero-nanostructures exhibit very good selectivity to ethanol. The sensing characteristics are related to the special heterojunction structures, confirmed by high-resolution transmission electron microscopy observation. Therefore, a heterojunction barrier controlled gas sensing mechanism is realized. Our results demonstrate that the hetero-nanostructures are promising materials for fabricating sensors and other complex devices.