Decoration of activated carbon nanotubes by assembling nano-silver

A facile solution processed strategy of synthesizing nano silver assembled on carbon nanotubes(CNTs) at room temperature was put forward.Activated carbon nanotubes were used as precursors for preparing silver-decorated nanotubes.The nature of the decorated nanotubes was studied using transmission electron microscopy(TEM),scanning electron microscopy(SEM),and energy-dispersive X-ray spectroscopy(EDX).The inert surfaces of carbon nanotubes were activated by introducing catalytic nuclei via an oxidation-sensit...     

Synthesis of zinc oxide nanoparticles with good photocatalytic activities under stabilization of bovine serum albumin

Zinc oxide nanoparticles were synthesized using bovine serum albumin as stabilizers through a facile one-pot strategy in aqueous media. The morphology and crystal phase of the zinc oxide nanoparticles were determined by transmission electron microscopy, X-ray diffractograms, and Fourier transform infrared spectroscopy. The synthesized ZnO nanoparticles exhibited strong absorption and photoluminescence properties in the visible wavelength region based on the fluorescence and UV-visible spectroscopy. Based on the results, the zinc oxide nanoparticles could effectively degrade the organic dyes through the mediation of the hydroxyl radical under visible light irradiation. Furthermore, the zinc oxide nanoparticles show good recycling stability during the photocatalytic experiments. These results suggested that the as-prepared zinc oxide nanoparticles might be used as a potential photocatalyst to efficiently treat the organic pollutants.     

Synthesis and Enhanced Electrochemical Activity of Ag-Pt Bimetallic Nanoparticles Decorated MWCNTs/PANI Nanocomposites

Ag-Pt bimetallic nanoparticles decorated on MWCNTs/PANI nanocomposites have been synthesized by in-situ chemical oxidative polymerization and chemical co-reduction method. The Fourier transform infrared(FT-IR) spectroscopy, X-ray diffraction(XRD), ultraviolet-visible(UV-vis) absorption spectroscopy, scanning electron microscopy(SEM) and transmission electron microscopy(TEM) were used to characterize the morphology and structure of the nanocomposites. It can be observed that the PANI was uniformly grown along the MWCNTs to form MWCNsT/PANI fiber-like nanocomposites with diameter about 60 nm, and the Ag-Pt binary nanoparticles were decorated onto MWCNTs/PANI with particle sizes around 6.8 nm. Cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) were used to characterize the electrochemical performance of the prepared electrode. The results demonstrated that the obtained MWCNTs/PANI/Ag-Pt electrode displayed a good electrochemical activity and fast electron transport, which has potential applications in biosensors and supercapacitors.     

Large scale synthesis of ZnO nanoparticles via homogeneous precipitation

In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100–180 °C under complete sealing condition. The ZnO precursors were calcined at 450 °C for 3 h to synthesize ZnO nanoparticles. The composition of the precursors and the formation mechanism of ZnO were studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The results of X-ray diffraction, transmission electron microscopy and scanning electron microscopy of the ZnO powders demonstrate that high-purity zincite ZnO nanoparticles are synthesized. Orthogonal experiments were performed to find out the optimal conditions for the maximum yield and the minimum size. The effect of temperature on the size of ZnO nanoparticles was investigated. The results show that a higher temperature is propitious to obtain smaller nanoparticles.     

Composite silicone rubber of high piezoresistance repeatability filled with nanoparticles

The ruthenium oxide nanoparticles with size less than 20 nm were fabricated by annealing the metallic ruthenium nanoparticles in air, which were synthesized by using the thermal reduction in the polyol solution. The rutile structure of the ruthenium oxide was proved by using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The oxide has good electron conductivity. The surface of the ruthenium oxide was modified by a vinyl silane coupling agent. The assembling of the silane to the oxide surface was proved by Infrared (IR) absorption spectroscopy. By mixing the nanoparticles with poly(methylvinylsiloxane) (PMVS) silicone rubber, a composite filled with dispersive conducting phase was fabricated. The temperature dependent conductivity shows that the electron transportation through composite is mainly dominated by tunneling. The measurement of piezoresistance shows that the composite at low strain has high piezoresistance repeatability. The 3D reconstruction images of the composite filled with carbon black or ruthenium oxide show that the aggregation of the nanoparticles differs much for two composites. The narrow distribution range of the particle size was thought to be the main factor for the high piezoresistance recurrence.     

ZnO/PVP纳米复合膜的光学特性

采用高分子网络原位合成法制备了ZnO/PVP纳米复合膜.并且通过多种测试手段对ZnO/PVP纳米复合膜的光学特性进行了分析.通过XRD,TEM的测试结果可知,以聚乙烯吡咯烷酮(PVP)为模板,原位合成ZnO纳米粒子,具有六角纤锌矿结构;分散性好,粒径分布窄等特点;从光致发光谱中可以看出由于PVP的引入,使得ZnO纳米粒...     

介孔氧化铟纳米粒子的制备及其气敏性质

以介孔氧化硅KIT-6为硬模板制备了介孔氧化铟纳米粒子,并对其进行了X射线粉末衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、氮气物理吸附分析。介孔氧化铟纳米粒子具有高的结晶度和有序介观结构,其尺寸为100 nm左右,比表面积为82 m2/g,孔径为4.5 nm左右,孔体积为0.42cm3/g。气敏性能测试结果表明介孔氧化铟纳米粒子对乙醇具有较好的敏感度,优于体相的氧化铟颗粒,在乙醇气体检测方面有潜在的应用。     

不同形貌氧化锌的红外发射率研究

在水热条件下,以硝酸锌、氢氧化钠、六次甲基四胺等为原料合成球形、棒状、束状和花状等不同微观形貌的ZnO粒子。采用透射电镜（TEM）、扫描电镜（SEM）和X射线衍射（XRD）等对其形貌和物相进行分析,利用IR-1红外发射率测量仪测量了不同形貌ZnO粒子在8~14μm波段的红外发射率,探讨ZnO的形貌对其红外发射率性能的影响。结果表明：各产物均为六方纤锌矿结构的ZnO,微米ZnO的红外发射率值比纳米的小,棒状、束状ZnO的发射率值比球形的要低,花状结构的ZnO的发射率值最低,为0.673。     

Preparation and Characterization of Multi Shape ZnO/PVDF Composite Materials

Two different morphologies of ZnO(lotus-shaped, rod-shaped) and ZnO/PVDF composite materials were prepared. The morphologies of ZnO and composite materials were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Fourier transform infrared spectroscopy(FT-IR), thermal gravimetry(TG), and X-ray diffraction(XRD) were also used to characterize the chemical structures and phase composites of ZnO and ZnO/PVDF composite materials. Breakdown voltage, dielectric constant and dielectric loss of ZnO/PVDF composite materials were also tested. Microstructure analysis showed that ZnO nanoparticles dispersed uniformly in the matrix. And the dielectric constant expresses a significantly improvement while the dielectric loss and breakdown voltage expresses no significant change. Moreover, dielectric constant keeps an improvement tendency with increasing content of ZnO.     

Low temperature doping of ZnO nanostructures

Doping of ZnO nanostructures was investigated by using a low temperature electrochemical process. Various dopant materials have been studied, including transition metals, group I, and group VII elements. The structure, composition, and optical properties of the doped ZnO nanostructures were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence, and x-ray diffraction. It was demonstrated that dopant elements were incorporated into the ZnO structures. The effects of dopant incorporation on the structure and properties of ZnO were also investigated. This low temperature approach is compatible with current micro-fabrication techniques and promising for large-scale production of doped ZnO nanostructures for optical and electronic applications.     

电化学沉积法制备一维氧化锌的研究

采用不同条件电化学沉积法在氧化铟锡（IT O ）导电玻璃基底上自组装生长了一维ZnO阵列。利用X射线衍射仪（XRD）和场发射扫描电镜（FESEM ）对其结构和形貌分别进行表征。结果表明,以种晶预生长时间为40 s的样品为衬底,Zn2＋浓度为0.005 mol/L ,CTAB浓度为0.005 mol/L ,HMT浓度为0.01 mol/L ,沉积时间为10 min ,沉积电位为0.90 V条件下,能够制备出高度取向且致密的一维氧化锌阵列。     

溶胶沉淀法合成修饰氧化铕溶胶与特性表征

以噻吩甲酰三氟丙酮（TTA）、1,10-邻菲罗啉（phen）作为修饰剂,采用溶胶沉淀法制备得到修饰纳米氧化铕甲醇溶胶。采用荧光光谱、紫外可见光谱（UV-Vis）和高分辨率透射电镜（HRTEM）等方法研究了NaOH浓度对修饰氧化铕有机溶胶荧光特性的影响和修饰氧化物纳米粒子的结构及性能。结果表明,用phen和TTA作为修饰剂得到的修饰氧化铕溶胶都能发出了Eu^3＋的特征红色荧光,NaOH浓度对修饰纳米氧化铕甲醇溶胶的荧光强度具有很大的影响;HRTEM和选区衍射实验表面纳米粒子的核心为氧化铕微晶,其平均粒径小于10nm。由于修饰氧化铕溶胶能发出很强的红色荧光,是一种潜在的优质发光材料。     

碳纳米管表面羟基化及其纳米流体的导热性能研究

采用强碱机械球磨技术对碳纳米管进行表面功能化。红外光谱和Zeta电位测试结果表明,处理后的碳纳米管表面已被羟基化;扫描电镜结果表明,处理后的碳纳米管已被截断短化。表面功能化并被截断短化的碳纳米管能够均匀稳定地分散在水中,得到的水基含碳纳米管纳米流体具有良好的传热性能。当碳纳米管体积分数为1．0％时,与水相比它的导热系数提高达17．5％。由于纳米粒子的润滑作用,在碳纳米管体积分数较低（Ф〈0．004）的情况下,含碳纳米管纳米流体的粘度要比基体流体水的粘度低;当碳纳米管的体积分数高于0．004时,含碳纳米管纳米流体粘度随着碳纳米管含量的增加而升高。     

纳米ZnO的可控生长及光致发光性能

为研究准一维纳米氧化锌的生长机理和光致发光性能,以预先氧化处理的锌粉为原料,采用化学气相法,在高温程控管式炉中通过调节温度、调控N2/O2混合气的比例和气体的压强等因素来控制纳米ZnO的形貌和光致发光特性。扫描电子显微镜(SEM)测试显示:合成的ZnO纳米线结构受温度,氧气分压影响较大;XRD衍射图谱显示:该纳米ZnO为六方纤锌矿结构,温度在900℃时最适合晶体纳米结构的生成,随着氧气流量的减少,c轴优势生长愈加明显;光致发光测试显示:其发光特性随着生长过程中温度的升高,氧相对含量的减少,蓝紫光发射减弱、蓝绿光发射明显增强,这种红移现象有力支持了氧空位和锌填隙是引起蓝绿光发射增强的主要原因。     

碳纳米管负载纳米硫化锌的制备与表征

利用微波辅助加热法,将表面功能化的多壁碳纳米管分散在乙二醇溶液中,并使醋酸锌与硫化钠在此溶液中反应,生成的纳米硫化锌粒子原位生长在碳纳米管的表面。生成的纳米硫化锌粒子密集分散在碳纳米管表面,粒子平均直径大约为1 nm。所生成的碳纳米管负载纳米硫化锌通过电子显微镜、X射线衍射分析,发现溶液中的碳纳米管不仅起到了负载基体的作用,而且在反应中改变了硫化锌的晶体结构。     

多壁碳纳米管负载ZnO纳米复合材料的制备及其光催化性能研究

采用溶胶法,以醋酸锌和硝酸处理过的多壁碳纳米管（MWCNTs）为主要原料,制备了MWCNTs-ZnO光催化复合材料。通过X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）等手段研究了制得样品的形态结构;通过紫外-可见分光光度计（UV-vis）,在紫外光照射下,分析比较了MWCNTs-ZnO复合材料、MWCNTs和ZnO的混合物以及纯ZnO对甲基橙光催化降解的性能。结果表明：在相同条件下MWCNTs-ZnO复合催化剂对甲基橙光降解有着最高的光催化活性。讨论了复合催化剂用量、重复使用等因素对甲基橙光催化降解效果的影响,并就复合催化剂的抗光腐蚀机制进行了初步的探讨。     

Self-assembly of Ag-TiO2 nanoparticles: Synthesis, characterization and catalytic application

The formation of Ag clusters on titanium oxide (TiO2) nanoparticles was achieved by self-assembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet visible spectroscopy (UV-Vis), and conventional techniques (XRD, TEM and UV-Vis) were used to identify Ag particles on the TiO2 surfaces. The results show that Ag-TiO2 particles can be applied to improve catalytic activity of the epoxidation of styrene oxides. Styrene oxide is the main product of catalytic reaction with H2O2 as the oxidant by using Ag-TiO2 nanoparticles as catalysts. High catalytic activitity of styrene oxide can be obtainable at 80 ℃. The reaction temperature, reaction time, the molar ratio of H2O2/styrene and solvent affect greatly the catalytic epoxidation of styrene.     

ZnO纳米颗粒的分散及光致发光特性

利用火焰喷雾法成功制备了ZnO纳米颗粒,通过对样品的X射线衍射谱（XRD）和场发射扫描电子显微照片（FESEM）分析,发现制备的颗粒大小较为均匀,直径在10-20nm左右;结合多种物理方法对样品进行分散处理后,FESEM表征显示颗粒间的团聚得到较好改善;光致发光谱表明随着颗粒尺寸的减小,样品的紫外发光和可见发光的强度逐渐增强．     

Synthesis and Evaluation on Performance of Hydrogen Storage of Multi-Walled Carbon Nanotubes Decorated with Platinum

1　IntroductionCarbonnanotubes (CNTs ) ,firstobservedin1991[1] ,haveattractedmoreattentionbecauseofmuchnewexcellentperformance ,andshowapromisingfutureashydrogenstoragemedia[2 ,3 ] .However ,comparedto5wt % - 10wt %hydrogenbytheoreticalcalculation[4] ,thecapacityofexperimentalstorageacceptedtodateisonly4 .2wt% [5] .Thelowstoragecanbeattributedtothehigh lygraphitizedsurfaceofCNTs ,whichhashigherresis tanceeffectsonhydrogenmoleculesandpreventshydrogenfromenteringthenanotubes[6] .Furthermore ,…     

Physiological Effects of MgO and ZnO Nanoparticles on the Citrus maxima

Toxicity of MgO and ZnO nanoparticles at concentrations of 250, 500 or 1 000 mg/L for Citrus maxima seedlings was investigated to evaluate the potentiality of their use as nano-fertilizers. Uptake and translocation of metal oxide nanoparticles and lipid peroxidation were measured and compared with those of plants exposed to the highest equivalent concentrations of Mg~(2+) and Zn~(2+). MgO nanoparticles were translocated from roots to shoots, while translocation of ZnO nanoparticles was low. Exposure to Mg~(2+) and MgO at all concentrations entailed severe toxicity and strong oxidative stress. ZnO nanoparticles showed only mild toxicity, while Zn~(2+) caused leaf vein chlorosis and strong oxidative stress to plant shoots. In conclusion, the toxicity of MgO nanoparticles to the plant resulted from the dissolved Mg~(2+) concentration, while that of ZnO nanoparticles was not correlated with the dissolved Zn~(2+) concentration. Our findings are significant for development and application of MgO and ZnO nanoparticles as nano-fertilizers in agriculture.