花状NH4V4O10微纳米结构的水热制备及电化学嵌锂性能

通过水热法制备了花状NH4V4O10微纳米结构. 采用XRD,SEM,TEM,XPS等测试手段对样品结构、形貌和组成进行了表征. 实验结果表明,所制得的NH4V4O10花状结构是由直径约100 nm,长度为几微米的纳米带团簇而形成. 研究了反应体系中温度、时间等因素对NH4V4O10产物形貌的影响. 将制备的NH4V4O10组装成锂模拟扣式电池,考察了其电化学嵌锂性能. 研究结果显示,所制备的花状NH4V4O10具有较高的比容量（307 mAh?g-1）,有望作为锂离子电池的新型正极材料.     

花状银微纳米结构的合成及SERS性质

通过简便的水溶液方法制备出一种新颖的由纳米片组成的花状银微纳米结构, 采用XRD, SEM, TEM, HRTEM和SAED等手段进行了表征. 考察了反应体系pH值对产物形貌的影响, 并对花状银微纳米结构的形成机理进行了初步探讨. 所制得的微纳米结构由许多纵横交错的纳米片组成. 实验结果表明, 制备的银微纳米结构作为表面增强拉曼散射(Surface-enhanced Raman Scattering, SERS)的基底具有很强的活性.     

微米级花状结构铜/聚乙烯吡咯烷酮的制备及其抗菌性能

采用液相还原的方法,以聚乙烯吡咯烷酮(PVP)为修饰剂,氯化铜为前驱体,水合肼为还原剂,成功制备了微米级Cu/PVP花状结构.采用扫描电子显微镜和X射线粉末衍射仪分析了所得样品的形貌与结构;利用差热分析测定了样品的热稳定性,并采用肉汤稀释法测试了其抗菌性能.结果表明,所制备的样品具有由多个Cu/PVP圆片组装而成的直径为6μm的花状结构,其形貌依赖于反应条件.与此同时,花状结构的Cu/PVP对金黄色葡萄球菌和大肠杆菌具有明显的抗菌作用,相应的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)分别为:41.25mg/L、82.5mg/L,以及20.63mg/L、82.5mg/L.与单一Cu纳米微粒相比,花状结构的Cu/PVP复合物的抗菌持久性明显较好.     

花状铜锌锡硫纳米颗粒的溶剂热法制备和结构表征

以金属氯化物为金属源,硫脲为硫源,聚乙二醇和乙二醇为混合溶剂,采用溶剂热法一步合成了花状的铜锌锡硫纳米颗粒.利用X射线衍射仪,扫描电子显微镜、能谱仪、透射电子显微镜、紫外-可见分光光度计分析了铜锌锡硫纳米颗粒的物相、结构、形貌及光学性能,并初步探讨了铜锌锡硫的生长机理.结果表明,所得到的铜锌锡硫纳米颗粒具有锌黄锡矿结构,直径在500～2 000nm范围内可调,其中花状的铜锌锡硫纳米颗粒由大量厚度约25nm的纳米片构成.所制备的铜锌锡硫纳米颗粒对可见光具有明显的吸收;利用外延法推算得到其禁带宽度约为1.5eV,与太阳能电池所需的最佳禁带宽度相近,显示其有望在新一代太阳能电池中得到应用和推广.     

氧化锌纳米棒的水热合成及其光催化性能

以分析纯ZnO作为锌源、NaOH为矿化剂、盐酸为反应溶液pH调节剂,利用水热反应制备了花状ZnO纳米棒;采用扫描电子显微镜和X射线衍射仪分析了产物的形貌和结构,考察了水热温度以及Zn2+和OH-浓度比对产物形貌的影响;以甲基橙为目标降解物,采用紫外-可见分光光度计研究了ZnO纳米棒的光催化性能.结果表明,在水热反应温度80℃、Zn2+/OH-浓度比1∶7.5条件下所得ZnO纳米棒呈花状聚合,直径约为200nm,长度约为2μm,具有六方纤锌矿结构.当甲基橙初始浓度为30 mg.L-1、ZnO纳米棒的投放量为1.5g.L-1时,以300W紫外灯照射150min,甲基橙的降解率可达90%.     

溶剂热法合成花状分级结构LiFePO_4及其电化学性能研究

以乙二醇/水为溶剂,酒石酸铵为添加剂和碳源,采用溶剂热法,制备了高振实密度(1.3 g·cm-3)的锂离子正极材料磷酸铁锂(LiFePO4)。采用X射线衍射(XRD)、红外光谱、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对样品进行了表征。研究结果表明样品为单晶纳米片组装而成的花状三维多孔分级结构LiFePO4。通过时间单因素实验探讨花状分级结构LiFePO4的生长机理,其生长过程概括为:成核和生长,定向组装。电化学性能测试结果表明LiFePO4样品具有优异的倍率性能(10C时放电比容量保持在74.8 m Ah·g-1)与循环性能(50次循环后容量保持率93%)。     

TiO2纳米管阵列制备及其电化学嵌锂性能研究

本文研究了TiO2纳米管阵列制备及其嵌锂电化学性能.采用阳极氧化法制备了TiO2纳米管阵列.利用XRD、SEM、恒电流充放电、CV、EIS等手段.对所制备TiO2纳米管阵列的结构、形貌进行了分析表征及电化学性能测试.实验结果表明,制备出的TiO2纳米管阵列薄膜具有很好的循环性能.首次嵌锂容量达73.3 μAh·cm-2...     

花状氧化锌纳米晶的制备及其电化学传感研究

本文以丙三醇为反应溶剂,在氧氧化钾体系中制备了两种花状氧化锌纳米晶.讨论了不同实验条件对氧化锌纳米晶形成影响,通过改变氢氧化钾浓度、反应温度和体系中水含量等条件来调节材料形貌.探讨了花状氧化锌纳米晶可能的形成过程.用X射线粉末衍射、扫描电子显微镜、紫外可见光谱等分析技术对制备的氧化锌纳米晶进行了表征.结果表明两种花状纳...     

花状3D纳米Pd/CeO2催化剂的制备及其性能研究

以PdCl2为前驱体,十六烷基三甲基溴化铵为保护剂,用超声波膜扩散法制备了Pd纳米粒子溶胶(E,Pd负载量1.0 wt%)。采用水热法制备了3D纳米花状Pd/CeO2催化剂(F),其结构,形貌和物理化学性能经XRD,SEM和N2吸附-脱附表征。考察了晶化时间对F形貌和晶型的影响。结果表明,晶化时间72 h制备的F72具有较高的比表面积(108 m2·g-1)和较大的孔体积(0.11 cm3·g-1);晶化时间48 h制备的F48呈现花状形貌,由大量厚度(20 nm～30 nm)均匀的纳米单元自组装而成。     

三维花状结构α-FeOOH纳米材料的制备与表征

以硫酸亚铁、尿素及乙醇为原料,采用低温常压一步回流法制备了具有三维花状结构的α-FeOOH纳米材料.考察了反应时间、反应温度、尿素浓度和乙醇用量对其结构和形貌的影响及α-FeOOH纳米材料对双氯芬酸钠的吸附性能.实验结果表明,当反应温度为90℃、反应时间为6 h、尿素浓度为0.1 mol/L、乙醇的体积分数为20%时,所得α-FeOOH纳米材料具有规整的三维花状结构,对双氯芬酸钠的吸附量达199.2mg/g.基于扫描电子显微镜(SEM)和X射线衍射(XRD)分析,推断三维花状结构α-FeOOH的生长机制包括定向聚集和外延生长2个过程,反应初期生成的高活性晶核快速形成不规则橄榄状颗粒并定向聚集成短簇状结构,再沿z轴方向外延生长,形成长簇的三维花状结构.     

表面修饰In纳米微粒的声化学法制备及结构表征

Surface modified indium nanoparticles were prepared by a simple and rapid process from bulk indium via ultrasound dispersion. The morphology and structure of synthesized nanoparticles were characterized by TEM, XRD, XPS and FTIR. The results show that the morphology of indium nanoparticles is spherical and the structure of indium nanoparticles is the tetragonal phase. The surface of indium nanoparticles was coated by 2 ethyl hexanoic acid, which could almost hold back oxidation of the indium nanoparticles. In addition, the tribological property of indium nanoparticles as additives in oil was evaluated on a four-ball tester and the results show that indium nanoparticles exhibit good performance in wear.     

Electrochemical fabrication of two-dimensional palladium nanostructures as substrates for surface enhanced Raman scattering

Two-dimensional palladium (Pd) nanostructures have been fabricated by electrochemical deposition of Pd onto an indium tin oxide glass substrate modified with a thin flat film of polypyrrole or a nanofibril film of polyaniline. The experimental results demonstrated that the morphology of Pd nanoparticles strongly depended on the properties of conducting polymers and the conditions of electrochemical deposition. Two-dimensional nanostructures composed of flower-like (consisting of staggered nanosheets) or pinecone-like Pd nanoparticles were successfully synthesized. They can be used as substrates for surface-enhanced Raman scattering after partly decomposing the polymer components by heating in air, and the enhancement factor of the substrate composed of flower-like Pd nanoparticles was measured to be as high as 105 for 4-mercaptopyridine.     

Electrochemical growth of two-dimensional gold nanostructures on a thin polypyrrole film modified ITO electrode

Two-dimensional gold nanostructures have been fabricated by electrochemical deposition of gold nanoparticles onto indium tin oxide (ITO) glass substrate modified with thin polypyrrole film. By controlling the electrodeposition conditions, gold nanoparticles with dendritic rod, sheet, flower-like (consisting of staggered nanosheets), and pinecone-like structures were generated. The flower-like gold nanoparticles showed high catalytic activity on electrochemical reduction of oxygen, and its activity was measured to be approximately 25 times that of gold pinecones and 10(4) times that of gold nanosheets in terms of gold weight. The pinecone-like nanoparticles can form a compact film with nano-/microscale binary structure like a lotus leaf surface. After modification with n-dodecanethiol, the surface showed superhydrophobic properties with a water contact angle of 153.4 degrees and a tilt angle of 4.4 degrees (5 microL droplet).     

液相分散法制备硬脂酸修饰铋纳米微粒

金属纳米微粒由于具有不同于普通材料的光、电、磁、热力学和化学反应等性能,在催化、信息存储、光电、微电子以及润滑等领域中有着广阔的应用前景。金属纳米微粒这些特殊的物理化学性能主要取决于制备工艺和具体的反应条件,因此研究具有特定性能的金属纳米微粒一直是纳米技术领域中的一个研究热点犤1,2犦,目前制备金属纳米微粒最常用的方法是液相法,它是通过在含有表面修饰剂的溶剂中还原相应的金属盐犤3,4犦或有机金属化合物热分解犤5,6犦来制备表面修饰的金属纳米微粒。虽然这种方法能够制备出多种具有特定性能的金属纳米微粒,但是这种方…     

Fabrication of flower-like silver nanoparticles for surface-enhanced Raman scattering

The flower-like silver nanoparticles have been synthesized by reducing silver nitrate (AgNO₃) with ascorbic acid (AA) as the reductant and polyvinyl pyrrolidone (PVP) as the capping agent under vigorous stirring. Such flower-like nanoparticles are aggregates of small nanoplates and nanorods. They were tested as substrates for the surface-enhanced Raman scattering (SERS), showing high sensitivity for detecting Rhodamine 6G (R6G) at a concentration as low as 10^-7 mol/L. It has been found that replacing mechanical stirring with ultrasound sonication would drastically change the particle morphology, from flower-like nanoparticles to well-dispersed smaller nanoparticles. Furthermore, when trace amounts of NaCl were added into the reagents, well-dispersed Ag nanoparticles formed even in vigorous stirring. These phenomena can be explained with the diffusion and reactant supply during nucleation and growth of Ag nanoparticles.     

Photochemical synthesis and self-assembly of gold nanoparticles

Colloidal gold was prepared by UV light irradiation of the mixture of HAuCl₄ aqueous solution and poly(vinyl pyrrolidone) (PVP) ethanol solution in the presence of silver ions. The resulting sheet-like nanoparticles were found to self-assemble into nanoflowers by a centrifuging process. The results of control experiments reflected that only suitable size sheet-like nanoparticles could assemble into the flower-like structures. The presence of Ag ions and PVP are essential for the formation process of nanoflowers. They perform their function by serving as structure-directing agents to produce the sheet-like particles. The appearance of the flower-like assemblages is attributed to the combination of Van der Waals force and the anisotropic hydrophobic attraction between the nanoparticles. The flower-like assemblages films can be used as surface-enhanced Raman spectroscopy (SERS) substrates with 4-aminothiophenol (4-ATP) molecule as a test probe.     

2,5-二疏基-1,3,4-噻二唑2,4-甲苯二异氰酸酯共聚物纳米粒子的制备及抗磨性能

二疏基噻二唑;共聚合;抗磨性能;2;5-二疏基-1;3;4-噻二唑2;4-甲苯二异氰酸酯共聚物纳米粒子的制备及抗磨性能     

以氨基酸为晶体生长控制剂合成多级纳米结构的硫化铟空心微球

以水热方法制备具有多级纳米结构的In2S3空心微球. 通过对不同反应时间产物的跟踪表征, 证明微球中空结构的形成归因于Ostwald ripening机理. 空心微球的壳层由In2S3的纳米粒子或纳米片组成, In2S3空心球的紫外可见光谱蓝移以及荧光光谱在约385 nm的强发射和364 nm的弱发射, 均显示了纳米尺度In2S3晶体的量子局限效应. 以不同的氨基酸作为晶体生长修饰剂, 可以选择性地制备不同表面形貌的In2S3空心微球, 显示了氨基酸的不同功能团在In2S3晶体生长过程中对表面形貌的控制作用.     

WS2纳米颗粒的合成及摩擦学性能研究

将自制的WO₃纳米颗粒前驱体与S粉混合,在自制的反应装置氢气氛中,于550～750 ℃下煅烧得到二硫化钨纳米颗粒,反应中用H₂代替H₂S以减少对周围环境的污染。该合成路线简单且产物纯度高。用XRD、SEM、TEM和HRTEM对二硫化钨纳米结构进行了表征和分析,并将WS₂纳米颗粒作为添加剂添加到N40基础油中,在MS-T3000摩擦磨损仪测试其摩擦学性能。结果显示:制备的二硫化钨颗粒平均粒径在50 nm以内,其形状为球形或类球形。WS₂纳米颗粒作为普通润滑油的纳米级固体添加剂表现出了较优异的摩擦学性能。     

铅纳米微粒用作油性润滑的摩擦学性能研究

The solution dispersion method has been successfully used to prepare Pb nanoparticles in a paraffin oilpolyglycol mixed solution by directly dispersing melted Pb granules. In this solution system,paraffin oil was used as reacting media and polyglycol served as an antioxidant to protect Pb nanoparticles from oxidizing. The size and structure of the prepared Pb nanoparticles were characterized by means of the transmission electron microscopy （TEM）and powder X-ray diffraction（XRD）. Their tribological behavior was evaluated with a four-ball tester. The TEM and XRD investigations reveal that the prepared Pb nanoparticles,with the average particle diameter of 70 nm,appear to be of close spherical shape and possess the same crystal structure as the bulk Pb. The tribological results show that the Pb nanoparticles as an oil additive exhibit good friction-reduction and antiwear properties at different additive concentration and applied load. Meanwhile,they can also strikingly improve the load-carrying capacity of the base oil. The rubbed surface was also investigated by the scanning electron microscope（SEM）and energy dispersive spectroscopy（EDS）. However,there was not presence of Pb element on the worn surfaces,which indicated that no chemical reaction occurred between the Pb nanoparticles and the rubbing surfaces. In addition,the tribological mechanism of the formation of the sliding-bearing system was also proposed.