电场对化学沉降制备的硫化镉纳米颗粒的影响

首次把外加电场作为环境因素,引入到在均匀溶液中化学沉降法制备的硫化镉纳米颗粒。用粉末X射线衍射(XRD)观察到,电场对化学沉降方式制备的硫化镉纳米颗粒生长方式的影响。用透射电子显微镜(TEM)观察到,外加电场显著地影响了获得纳米颗粒的形貌。外加静电场成为一种能够影响纳米颗粒在溶液中生长的新手段。     

辐射法制备具有核壳结构的CdS/PSt纳米复合微球

利用辐射法制备了具有核壳结构的硫化镉/聚苯乙烯(CdS/PSt)纳米复合微球。用粉末X射线衍射(XRD),红外吸收光谱等手段表征了产物的结构。用透射电子显微镜(TEM)观察了复合材料的形貌及复合材料的分散情况,获得了复合材料CdS纳米颗粒具有空心结构。     

金属氧化物纳米粒子的制备与表征

在乙二醇-水体系中,以CuSO4和尿素为反应物制备了分散性较好的CuO纳米粒子.用粉末X-射线衍射(XRD)和扫描电子显微镜(SEM)表征了样品的物相和微观形貌.结果表明,所得样品为单斜相的CuO纳米粒子,颗粒均匀,粒径约30 nm.讨论了溶剂组成、反应物浓度等实验条件对样品形态的影响.并用此方法制备了粒度均匀的ZnO纳米粒子和MnO2纳米粒子.     

功能化四氧化三铁的合成和表征及其对钙离子的吸附

结合磁性纳米颗粒及功能基团各自的特性,设计了具有可以螯合金属离子的功能型磁性纳米颗粒,以获得选择性高、操作简易且回收后可重复利用的钙离子吸附剂.以三氯化铁和硫酸亚铁为铁源,采用化学共沉淀法在氩气保护下制备磁性纳米颗粒四氧化三铁;通过硅烷化反应在磁性纳米颗粒上依次包覆二氧化硅及γ-氨丙基三乙氧基硅烷.以甲基丙烯酸及乙二胺为原料通过迈克尔加成及酰胺化反应合成了含酰胺键、酯基、氨基功能基团的磁性纳米颗粒.X-射线粉末衍射线、傅立叶红外、扫描电镜、热重分析、X-射线光电子能谱等技术的分析结果表明已合成各中间体及功能化的纳米颗粒.原子吸收光谱研究表明该纳米颗粒可通过其配位基团按理论配比螯合钙离子.随着功能基含量的增加,吸附钙离子的能力也会随之增强,因此,含较多功能基的该类磁性纳米颗粒有望用作水中钙离子的吸附剂.     

化学还原法制备银纳米颗粒

在70℃时采用聚乙烯吡咯烷酮(PVP)和氢氧化钠的混合水溶液,利用葡萄糖还原硝酸银制备了银纳米颗粒.采用X射线衍射(XRD)、能量分散谱(EDS)和扫描电子显微镜(SEM)对所制备的银纳米颗粒进行了表征.结果表明该法制备的银颗粒为纯的银纳米颗粒,呈球形,粒径分布集中在20～50 nm之间.     

二硫化钼/氧化钛纳米复合颗粒的制备及其电流变性能

利用化学剥离法制备出片层状的二硫化钼,以其作为载体,通过水解法使纳米二氧化钛包覆在二硫化钼上,并采用这种复合颗粒作为分散相制备出电流变液。使用扫描电镜(SEM),X-射线衍射(XRD)对该复合颗粒表面形貌和晶型结构进行了表征,利用电流变仪对电流变液进行了流变性能测试。从SEM照片中看出复合颗粒形貌均一。同时该复合颗粒制备出的电流变液在不同电场下剪切应力提升明显,展现出较强的电流变性能。     

分散方式对Ni-Si_3N_4纳米复合电镀层显微组织和性能的影响

采用超声波分散加机械搅拌技术在纯铜板上制备了含有纳米Si3N4颗粒的镍基纳米复合镀层,研究了分散方式对复合镀层中纳米颗粒含量、复合镀层组织结构、显微硬度和磨损性能的影响。利用扫描电镜(SEM)和X-射线衍射仪(XRD)分析了镀层表面的显微组织及相结构,通过磨损实验机检测了复合镀层的耐磨性能。结果表明,采用超声波分散技术可获得组织细密、高显微硬度的纳米复合镀层,其显微硬度最高可达996 HV,耐磨性能较未经超声波分散处理的镀层有显著提高。     

ZnFe_2O_4纳米粒子磁共振成像性能研究

采用多元醇法制备了粒径约为6nm的ZnFe2O4纳米粒子,通过表面修饰得到了稳定的ZnFe2O4纳米粒子水相分散液。用X-射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、动态光散射仪(DLS)、磁性能测量系统(MPMS)、磁共振分析仪等手段对样品进行表征。结果表明,所制备纳米粒子磁共振成像性能良好。     

碳纳米颗粒增敏的分子印迹电化学传感器检测阿奇霉素的研究

以磺化沥青(sulfonsted bitumen, SP)作为碳源,通过纯化和高温碳化法制备碳纳米颗粒(carbon nanoparticles, CNPs),将CNPs分散在壳聚糖(chitosan, CS)溶液中,并用滴涂法修饰在金电极(Au)上来得到CNPs-CS/Au。以阿奇霉素(azithromycin, AZM)为模板分子、多巴胺(dopamine, DA)为功能单体,利用电聚合法在CNPs-CS/Au电极上制备了AZM分子印迹薄膜,构建了高灵敏度且专一性识别AZM分子的电化学传感器(MIP/CNPs-CS/Au)。分别采用扫描电镜(scanning electron microscope, SEM)、X-射线衍射(X-ray diffraction, XRD)、X-射线光电子能谱(Xray photoelectron energy spectroscopy, XPS)、循环伏安法(cyclic voltammetry, CV)、电化学阻抗法(electrochemical impedance method, EIS)和差示脉冲阳极溶出伏安法(differential pu...     

氧化铜/石墨烯纳米流体的制备及光吸收-光热性能

采用湿化学方法制备得到氧化铜纳米颗粒,进而制备氧化铜纳米流体并与石墨烯纳米流体复合得到CuO/G纳米流体.利用X-射线衍射、透射电镜、紫外-可见分光光谱仪等测试方法对样品进行表征.CuO/G纳米流体在太阳光波段显示出比氧化铜纳米流体和石墨烯纳米流体更加优异的光吸收性能,随着石墨烯含量的增加,CuO/G纳米流体的辐照度逐...     

水热条件下由纳米颗粒自组装成的亚微米级球形CdS的制备

利用不同的无机镉盐为镉源,在水热条件下合成亚微米级的硫化镉（CdS）球形颗粒。X射线衍射分析（XRD）说明所得的CdS材料为六方晶体结构,扫描电镜（SEM）显示材料为亚微米级球形颗粒,且这些颗粒是由纳米级粒子自组装而成。通过加入一定体积的乙醇可以极大地改善颗粒的形貌和尺寸分布,从热力学上对反应的可行性进行了分析,提出了球形CdS材料的形成机理。     

Syntheses and Evaluations of CdS with Various Morphologies for Photocatalytically Reducing CO_2

A series of CdS with various shapes of microsphere, flower-like and leaf-like were templatefreely synthesized by a hydrothermal method. Powder X-ray diffraction(XRD), Brunauer-Emmett-Teller(BET), scanning electron microscopy(SEM) and UV-vis absorption spectroscopy(UV-vis) were applied to characterize the morphology, optical and other physical properties of the as-prepared CdS. An optical spectrum analyzer was used to measure the wavelength of the illuminant on the slurry in the activity evaluations of photocatalytic reduction of CO_2 over CdS. Both sources of cadmium and sulfur had great impact on the CdS morphology as can be seen in the SEM images. By means of a series of activity evaluations, the microspheric CdS made from cadmium nitrate and thioacetamide showed better photocatalytic activity for the reduction of CO_2 to methyl formate(MF) in methanol than the flower-like and leaf-like CdS catalysts.     

Photorefraetive Effect in a CdS Nanoparticles- sensitized Polymer Composite

The photorefractive （PR） performance of an organic/inorganic hybrid polymer composite sensitized by CdS nanoparticles, combining poly（N-vinylcarbazole） （PVK）, the second-order optically nonlinear chromophore 1-n-butoxy-2-methyl-（4-p-nitropheylazo）benzene （BMNPAB） and 9-ethylcarbazole （ECZ） was studied. It was confirmed that the CdS colloidal particles had a nanoscale size and quantum confinement effect adopting transmission electron microscopy and UV-Vis absorption spectroscopy. The addition of CdS nanoparticles as a photosensitizer in PVK will be significant enhancement of photoconductivity because of the high photocharge generation quantum efficiency and high charge transport to conducting polymer. The polymer composite film exhibited PR effect with a method of two-beam coupling experiment. And an asymmetric two. beam coupling gain of 45.8 cm^-1 without applied electric filed is obtained at 632.8 nm wavelength.     

Syntheses and evaluations of CdS with various morphologies for photocatalytically reducing CO<Subscript>2</Subscript>

A series of CdS with various shapes of microsphere, flower-like and leaf-like were templatefreely synthesized by a hydrothermal method. Powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and UV-vis absorption spectroscopy (UV-vis) were applied to characterize the morphology, optical and other physical properties of the as-prepared CdS. An optical spectrum analyzer was used to measure the wavelength of the illuminant on the slurry in the activity evaluations of photocatalytic reduction of CO₂ over CdS. Both sources of cadmium and sulfur had great impact on the CdS morphology as can be seen in the SEM images. By means of a series of activity evaluations, the microspheric CdS made from cadmium nitrate and thioacetamide showed better photocatalytic activity for the reduction of CO₂ to methyl formate (MF) in methanol than the flower-like and leaf-like CdS catalysts.     

油酸钠为稳定剂合成CdS（CdSe）纳米粒子及表征

针对CdS（CdSe）等半导体纳米粒子制备过程中使用的有机溶剂难回收、成本高、难以实现工业化等问题,以油酸钠为稳定剂,乙醇为溶剂,乙酸镉和硫脲（或硒氢化钠）为前驱物,制备了CdS和CdSe纳米粒子.采用紫外-可见吸收光谱、荧光光谱、广角x射线衍射和透射电子显微分析等方法,对CdS和CdSe纳米粒子的光学性质、晶体结构、形貌及尺寸等进行了表征.结果表明,当以油酸钠为稳定剂,乙醇为溶剂时,通过控制一定的前驱物浓度、反应温度和反应时间,在温和的反应条件下,可以得到尺寸分布均匀的CdS和CdSe纳米粒子,从而为在环境友好条件下合成CdS和CdSe半导体纳米粒子提供了一种新途径.     

Composite semiconductor quantum dots CdSe/CdS Co-sensitized TiO2 nanorod array solar cells

CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide (FTO) substrate using the hydrothermal and successive ionic layer adsorption and reaction (SILAR) process. The structural and morphological properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results indicate that CdSe/CdS QDs are uniformly coated on the surface of the TiO2 nanorods. The shift of light absorption edge was monitored by taking UV-visible absorption spectra. Compared with the absorption spectra of the TiO2 nanorod array, deposition of CdSe/CdS QDs shifts the absorption edge to the higher wavelength. The enhanced light absorption in the visible-light region of CdSe/CdS/TiO2 nanorod array indicates that CdSe/CdS layers can act as co-sensitizers in quantum dots sensitized solar cells (QDSSCs). By optimizing the CdSe layer deposition cycles, a photocurrent of 5.78 mA/cm2, an open circuit photovoltage of 0.469 V and a conversion efficiency of 1.34 % were obtained under an illumination of 100 mw/cm2.     

Preparation and Characterization of Monodisperse Nickel Nanoparticles by Polyol Process

Polymer-protected monodisperse nickel nanoparticles were synthesized by a modified polyol reduction method in the presence of poly（N-vinyl-2-Pyrrolidone）.These nanoparticles were characterized by transmission electron microscopy（TEM）,X-ray diffraction（XRD）,selected area electron diffraction（SAED）,as well as vibrating sample magnetometer（VSM）.The experimental results show that the addition of PVP and the concentration of NaOh have strong influences on the size.agglomeration and uniformity of nanoparticles.In the presence of PVP and NaoH with low concentration.smonodisperse nickel nanoparticles with average diameters about 42 nm were obtained and characterized to the pure nickel crystalline with foc structure.Secondary structures such as clusters.loops.and strings resulted from magnetic interactions between particles were observed.The chemical interaction between the PVP and nickel nanoparticles was found by FTIR.The saturation magnetization（Ms）.remanent magnetization（Mr）and coercivity（Hc）of these nickel nanoparticles are lower than those of bulk nickel.     

ZnFe_2O_4纳米粒子的制备及其磁性能

以乙酰丙酮铁和乙酰丙酮锌为原料、三甘醇为溶剂,采用一步法制备ZnFe2O4纳米粒子。通过透射电子显微镜(TEM)、X-射线粉末衍射仪(XRD)和磁性能测量系统(MPMS)等表征手段对ZnFe2O4纳米粒子进行了表征。结果表明,所制备的ZnFe2O4纳米粒子平均粒径约为6 nm,尺寸均匀,水溶性良好,在室温条件下呈现超顺磁性。     

Formation and characterization of CdS hollow structures

CdS hollow structures were built up by using the one pot method and using carbon disulfide （CS2） and ethylenediamine as starting materials. CS2 is insoluble in water and could form metastable oil droplets in the water at a moderate temperature. The oil droplets formed chains in the circumvolving water. CdS crystals grew and mineralized on the surfaces of the CS2 droplet chains, forming CdS shells around the unreacted CS2 cores. After the surrounding temperature was raised above the boiling point of CS2, the unreacted CS2 cores vaporized, leaving the CdS shelled hollow structures. The CdS hollow structures were characterized by using a transmission electron microscope, an X-ray diffractometer, a UV-Visible spectrophotometer and a fluorescence spectrophotometer. The CdS hollow structures were mainly tubes with closed ends. The exterior diameter and the interior diameter of tubes were about 50 nm and about 15 nm, respectively. Compared with the absorption onset wavelength of the bulk CdS, the CdS hollow structures exhibited a blue shift of about 57 nm. While excited at 213 nm, the CdS hollow structures emitted greenish blue light centered at 470 nm.     

蒸发速率对电子束蒸发法制备CdS薄膜性质影响

采用电子束蒸发法,以高纯CdS块料为膜料在玻璃基底上制备了CdS薄膜。利用X射线衍射仪和原子力显微镜表征其晶体结构和表面形貌,用四探针电阻测试仪和紫外可见分光光度计分析其电学及光学特性。结果表明,蒸发速率对薄膜结构及特性有显著影响,其中在蒸发速率为10?S-1制备的CdS薄膜均匀致密且其XRD衍射峰强度最大,薄膜的光电性能最好。这些CdS薄膜的光敏性达到7.7×102,其中亮电阻的最小值为1350Ω/□。