表面活性剂种类对纳米氧化锌形貌的影响

利用简单的水热法,以Zn(Ac)2.2H2O为锌源,通过调整表面活性剂的种类及碱源,制备了一系列不同形貌的纳米结构氧化锌;利用场发射扫描电子显微镜和X射线粉末衍射仪分析了产物的形貌和晶体结构,并探讨了多种表面活性剂和醋酸钠碱源对氧化锌纳米结构的影响.结果表明,以NaOH作为碱源时,在不添加任何表面活性剂的情况下,产物的形貌结构与氢氧化钠的加入量有关,当n(Zn2+)∶n(OH-)为1∶2.5、1∶10及1∶20时,分别得到片状、棒状及海胆状纳米结构的氧化锌;产物均为六方相氧化锌.     

阴离子氨基酸表面活性剂调控下水热合成羟基磷灰石纳米片

利用水热合成方法, 在含有氨基酸结构的阴离子表面活性剂N-酰基十二烷基肌氨酸钠(Sar-Na)的控制下, 合成具有较大长径比(aspect ratio)的片状纳米羟基磷灰石晶体. 采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)和傅立叶变换红外(FTIR)光谱表征, 并分析了合成产物的形貌、结构和组成. 结果表明, 在Sar-Na的调控下合成了长度0.5-1.0 μm、宽约30 nm的片状羟基磷灰石晶体, 其长径比约为20:1. 考察了表面活性剂Sar-Na的用量对羟基磷灰石形貌的影响. 随着Sar-Na的添加及用量的增加, 羟基磷灰石由椭圆形变为长片状, 并且片的两端逐渐变尖. 结果显示了Sar-Na对羟基磷灰石形貌的控制作用, 为合成具有较大长径比的羟基磷灰石纳米片提供了一个新的途径.     

三角形银纳米片的合成及其影响因素

报道了一种在不需光照的条件下制备三角形银纳米片的新方法.在表面活性剂BRIJ35存在下,将硝酸银用硼氢化钠和柠檬酸钠还原,在不同温度范围内反应形成各种尺度的三角形银纳米片,探讨了硼氢化钠浓度、BRIJ35浓度和表面活性剂的种类和溶液pH值等因素对银纳米颗粒形貌和尺寸的影响.     

Zn基片上ZnO及ZnS/ZnO复合纳米阵列的液相合成及发光性质

采用温和的溶液路线在Zn基片上合成了单晶态的ZnO纳米棒阵列、 纳米片阵列和ZnS/ZnO复合双层纳米棒阵列. 使用X射线粉末衍射仪、 扫描电子显微镜、 高分辨透射电子显微镜、 X射线光电子能谱仪等对产物的组成、 结构及形貌进行了表征. 讨论了表面活性剂在液相合成中对产物形貌的调控作用. 通过室温发射光谱的测定, 研究了所得纳米阵列材料的发光性质.     

特殊形貌GdF3:Eu3+纳米发光材料的制备及性能

以PEG-2000、柠檬酸和甘氨酸为表面活性剂,采用水热法制备出扁平纳米棒、纳米花和纳米片状的GdF3:Eu3+发光材料,并对其结构和性能进行了表征.XRD结果表明,所得样品均为正交晶系.FESEM照片表明,使用不同表面活性剂所制备的产物形貌不同.研究了以PEG-2000为表面活性剂时反应物浓度对产物形貌的影响,并对其...     

S2-控制剂对Ag纳米产物的形貌及光学性能的影响

采用改装的微波冷凝回流装置,以乙二醇作为还原剂和溶剂,在表面活性剂聚乙烯吡咯烷酮的保护下,添加Na2S与AgNO3反应生成Ag2S,对Ag2S进行热分解即可获得Ag纳米产物。保持其它参数(加热功率、加热时间、表面活性剂浓度和反应物溶液浓度等)不变的条件下,通过改变Na2S的浓度得到不同形貌的Ag纳米产物。利用扫描电子显微镜、X射线衍射仪和紫外-可见分析仪对所得Ag纳米产物的形貌、物相和光学性能进行分析表征,结果表明,在微波冷凝回流作用下,Na2S浓度的逐渐增大使银纳米产物经历了一个类球形-立方体-线形的形貌演变。此外,通过分析反应过程,对S2-如何影响Ag纳米产物的形貌及Ag纳米线的生长机理作了进一步研究探讨。     

氢氧化镁纳米片的合成及其润滑性能的研究

以硫酸镁和氢氧化钠为原料,油酸为表面修饰剂,采用原位合成的方法制备出了疏水性的Mg(OH2)纳米片.研究了反应温度、反应物浓度等因素对氢氧化镁纳米片平均粒径的影响.用X-射线粉末衍射(XRD)、红外(IR)和热重(DTA-TGA)及扫描电子显微镜(SEM),对制备出的Mg(OH)2纳米片的结构和形貌进行了表征,证实制备出的Mg(OH)2纳米片具有良好分散性,纳米片尺度为200～300nm,厚度10nm.摩擦实验证明Mg(OH2)纳米片可以作为润滑油中的添加剂来应用.     

不同形貌纳米氧化锌的水热法合成

以氯化锌为锌源,以氢氧化钠为碱源,采用水热法合成了不同形貌的纳米氧化锌;探讨了晶化时间、晶化温度、表面活性剂十六烷基三甲基溴化铵(CTAB)对纳米ZnO形貌的影响.结果表明:不添加CTAB时,在120℃下反应24h得到的纳米氧化锌为颗粒状,而在160℃下反应24h得到的纳米氧化锌为片状.当添加CTAB后,在120℃可得到片状氧化锌,而在160℃可得到颗粒状氧化锌.     

室温固相化学反应合成表面修饰的碘化铅纳米棒

以硝酸铅和碘化钾为原料, 在体系中添加表面活性剂聚乙二醇(PEG), 采用一步室温固相化学反应制备出聚乙二醇表面修饰的碘化铅纳米棒, 利用X射线衍射, 红外光谱, 透射电子显微镜, 扫描电子显微镜, 热分析和元素分析等手段对其进行了表征. 实验结果表明: 在体系中添加的表面活性剂PEG不仅与碘化铅纳米棒发生了化学键合作用, 而且对产物形貌的控制起到决定作用, 形成了表面键合有聚乙二醇的碘化铅纳米棒, 其中被PEG600修饰的碘化铅纳米棒粗细均匀, 表面光滑, 直径约为100 nm, 长度达2 μm.     

Trition X-100/C_(10)H_(21)OH/H_2O体系层状液晶中纳米羟基磷灰石粉体的合成

本文以Triton X-100/C10H21OH/H2O体系层状溶致液晶为模板,Ca(NO3)2和(NH4)2HPO4为反应物,在一定的pH条件下,通过三元相图确定了层状液晶单相区域,并合成了羟基磷灰石(HA)纳米颗粒。用傅立叶红外光谱(FTIR),X射线衍射(XRD)和透射电子显微镜(TEM)对产物进行了表征。并考察了不同助表面活性剂浓度和不同表面活性剂浓度对产物的形貌和尺寸的影响。结果表明所制备的HA纳米颗粒平均直径为8~10nm、长度在100nm左右,呈针状。助表面活性剂浓度对HA形貌及尺寸影响不大,但是在一定范围内改变表面活性剂浓度可以起到调控HA纳米颗粒形貌和尺寸的作用。     

氧化铜纳米片及其自组装球状纳米结构的制备及催化作用

氧化铜具有独特的光电和光化学性能,可被用来制作太阳能电池或高能锂电池~([1,2]).纳米氧化铜还可以作为催化剂、载体以及电极活性材料等~([3-7]).在实际应用中,纳米材料的结构和形貌对其性能有很大影响.     

微乳液合成胶体CuO/γ-Al2O3及其催化芳香硝基化合物还原（英文）

Monodispersed colloidal copper oxide nanoparticles were synthesized by water-in-oil microemulsion using CuCl 2·H2O and NaOH.The effect on CuO particle size was studied by varying the water-to-surfactant molar ratio,precursor concentration and molar ratio of NaOH to CuCl2.The morphology,size and size distribution of the particles were studied by transmission electron microscopy and dynamic light scattering.Dispersion destabilization of the colloidal copper oxide nanoparticles was detected by a Turbiscan apparatus.CuO/γ-Al2O3 catalysts were prepared by dispersing highly stable CuO nanoparticles on γ-alumina by mechanical stirring.The catalysts were analyzed by scanning electron microscopy,transmission electron microscopy,X-ray photoelectron,and X-ray diffraction,which confirmed the uniform dispersion of CuO on the support.The reduction of the nitro aromatic compounds,4-nitrophenol,3-nitrophenol,and 2-nitrophenol,were studied.The CuO/γ-Al2O3 catalysts were active for the reduction of these nitro aromatic compounds.     

氧化铜纳米晶的合成及性能研究

通过水热方法,合成出CuO纳米片,类纳米花等纳米结构,X光衍射表明样品为单斜CuO,透射电镜和高分辨透射电镜表征了样品的形貌和尺寸,观察到CuO纳米晶是由小的晶粒聚集而成的多晶结构。同时讨论了实验中各实验参数在合成CuO纳米晶时所起的作用： KOH具有促进CuO结晶的作用;十六烷基三甲基溴化铵可以控制反应产物尺寸;柠檬酸钠能够影响纳米粒子的排布规则程度,从而进一步影响CuO纳米晶的形貌和尺寸。另外我们还研究了CuO纳米片的光学性能和氮气吸附性质。     

Room temperature electrochemical synthesis of CuO flower-like microspheres and their electrooxidative activity towards hydrogen peroxide

We describe a facile electrochemical route for the synthesis of CuO flower-like microspheres (CuO FMs) by anodic dissolution of bulk Cu in sodium hydroxide solution at room temperature and without heating. Scanning electron microscopy and X-ray diffraction revealed that the CuO FMs are phase-pure monoclinic crystallites and comprised of CuO nanoflakes. The concentration of NaOH has a large effect on the size of the CuO FMs. The possible formation mechanism is discussed. The CuO FMs are electrocatalytically active towards the oxidation of H₂O₂, and this has resulted in a sensor for H₂O₂. To our knowledge, this is the simplest way to obtain clean CuO FMs.

水浴法制备蝴蝶状的微结构CuO

以硝酸铜为铜源,六次甲基四胺为有机碱,去离子水为溶剂,采用简捷水浴加热技术控制合成了由三角纳米片组成的蝴蝶状微结构CuO。产品的组成和形貌用XRD、EDX、场发射扫描电镜(FESEM)、TEM、HRTEM和选区电子衍射(SAED)进行了表征。结果表明CuO的形貌主要受六次甲基四胺用量的影响。随着其用量的增加,CuO的形貌经历了飞鱼状-蝴蝶状-牡丹状的递变。并对蝴蝶状CuO微结构的形成机制及形貌的演变进行了探讨。     

Self-assembled Synthesis of 3D CuO Flocculus-like Nanosheet-based Hierarchical Nanostructures

A simple, surfactant-free, and environmentally benign method has been developed to synthesize a novel 3D flocculus-like CuO hierarchical nanostructure self-assembled with 2D nanosheet as building blocks. Detailed proofs demonstrate that the overall synthetic process underwent the dehydration and re-crystallization of precursor Cu(OH)₂ nanowires, and the subsequent two-step oriented attachment. In addition, 3D butterfly-like and flower-like CuO nanostructures consisted of 2D nanosheets could be obtained by adjusting the concentration of NaOH(c_NaOH) in the solution. c_NaOH played a key role in tailoring the thickness of the nanosheets and changing the morphology of the product. This report may be helpful to constructing fine-tune hierarchical CuO nanostructures under basic conditions.     

Preparation and characterization of zinc oxide nanoflakes using anodization method and their photodegradation activity on methylene blue

In this work, we report the formation of leaf-like ZnO nanoflakes by anodization of zinc foil in a mixture of ammonium sulfate and sodium hydroxide electrolytes under various applied voltage and concentration of sodium hydroxide. The morphology and structure of ZnO nanoflakes were investigated by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. In addition, the photocatalytic activity of the prepared nanoflakes zinc oxide was evaluated in the photodegradation of organic dye methylene blue (MB) solution under UV irradiation. It was found that zinc oxide prepared under high concentration of sodium hydroxide and high voltage showed better performance in the photodegradation of methylene blue.     

Preparation of TiO2 Nanoflakes and Their Influence on Lithium Ion Battery Storage Performance

TiO₂ nanoflakes were prepared by hydrothermal precipitation method using Ti(SO₄)₂ as titanium source and NaOH solution as alkaline medium. Their surface morphology, grain size measured after high temperature calcination and effect on the electrochemical performance of Li ion battery were discussed. TiO₂ nanoflakes were characterizated by means of transmission electron microscopy(TEM), X^-ray powder diffraction(XRD), N₂ adsorption-desorption isothermal assay, cyclic voltammetry(CV) and cycle performance test. The result of electrochemical performance test shows that the prepared TiO₂ nanoflakes have high discharge specific capacity and good cycle performance. Discharge specific capacity for the first circle at the discharge rate of 0.1 C is 261.5 mA·h·g^-1. After 90 cycles, the discharge capacity reduces to 172.2 mA·h·g^-1.     

Using a Natural Surfactant for Synthesize of NiO and CuO Nanostructures via Simple and Fast Microwave Approach

NiO and CuO nanostructures were synthesized successfully via simple and fast microwave approach. Olive oil was chose as surfactant for stabilizing nanostructures. Different parameters such as microwave time and power and olive oil concentration were investigated on product size and morphology. The products were characterized with X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy and energy dispersive spectrometry analysis.     

Controlled synthesis of CuO nanostructures by a simple solution route

A simple solution route has been developed to prepare nanostructured CuO with Cu(NO₃)₂·3H₂O and NaOH as starting materials. CuO nanoribbons or nanorods and their assemblies into hierarchical structures have been synthesized, respectively, by controlling the molar ratio of NaOH to Cu(NO₃)₂, reaction temperature and the concentration of the starting NaOH solution. Experiments demonstrate that the molar ratio of NaOH to Cu(NO₃)₂ is an important parameter which may decide whether CuO exists in nanoribbons (nanorods) or assemblies into hierarchical structures. Whether Cu(NO₃)₂ is dissolved in ethanol or water also influences the formation of monodispersed CuO nanoribbons (nanorods). The growth mechanism of these nanostructures is discussed. The products were characterized by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy (HRTEM) and their optical absorption spectra were also studied.