络合物对制备纯相BiFeO_3纳米晶的影响

采用溶胶-凝胶法用聚乙烯醇(PVA)和酒石酸两种不同络合物制备了BiFeO3纳米晶。通过优化两种络合物的制备工艺,在400℃的低温下以酒石酸作络合物时,得到了纯相的BiFeO3纳米晶。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)测量分析了样品结构和形貌,研究了溶胶-凝胶制备工艺和不同络合物对BiFeO3纳米晶的形成及晶体结构的影响。     

超声辅助合成CeF3纳米晶及其表征

用超声波辅助法制备了CeF3纳米晶.并用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线粉末衍射(XRD)、紫外吸收(UV)光谱和荧光光谱(PL)对纳米晶的结构与性能进行了表征.结果表明:超声时间对所制备的CeF3纳米晶的形貌有很大的影响.随着超声时间的延长,所制备样品的形貌由"笼形"演变为规整的盘形.随着样品粒径的减小,纳米晶的紫外吸收峰和吸收带边发生明显的蓝移.纳米晶的荧光强度与纳米晶的结晶程度有关.     

滴加方式对NAC-FAS工艺制备ZnO-TiO_2复合纳米晶的影响

以硫酸氧钛、二水合乙酸锌、氢氧化钠为原料,研究了不同的滴加方式对NAC-FAS工艺制备ZnO-TiO_2复合纳米晶的影响,利用X射线衍射仪(XRD)、透射电子显微镜(TEM)对样品的结构、形貌进行了表征。结果表明:通过NAC-FAS工艺预制TiO_2纳米晶可以制备得到复合ZnO-TiO_2纳米晶,其平均粒径为15nm,复合纳米晶呈球状。通过NAC-FAS工艺直接滴加反应溶液,不能制备得到ZnO-TiO_2,只能制备得到单一晶相或非晶相。     

有机-无机复合CdS纳米晶的制备及表征

本文采用液液两相法,在甲苯、甲醇和水两相体系中制备了烷基硫醇和芳杂环硫醇修饰的有机-无机复合的CdS半导体纳米晶.通过紫外可见吸收光谱、X-射线光电子能谱、X-射线粉末衍射、透射电子显微镜、元素分析和热重分析检测手段对样品的结构和组成进行了表征.结果表明:该方法所制备的硫化镉纳米晶是由无机纳米核及通过化学键吸附在其表面的硫醇分子所组成.纳米晶的平均粒径约为5nm,尺寸均匀,稳定性高,在空气中可长时间保存.     

NaCl熔盐法制备ZnO片状纳米晶及其光学性能研究

通过在NaCl熔剂的液态环境中热分解商业2ZnCO3·3Zn(OH)2固体粉末,成功制备出ZnO片状纳米晶。用X射线粉末衍射和透射显微镜研究了所制备纳米晶的成分、晶相、形状和尺寸。采用室温光致发光技术研究了ZnO片状纳米晶的发光性能。研究表明:所制备的ZnO片状纳米晶在波长为486nm处发出强蓝光。通过透射电子显微镜技术对ZnO纳米晶形态的深入研究,深入分析了ZnO片状纳米晶的生长过程,提出了在NaCl液态环境中,ZnO片状纳米晶按奥斯瓦尔德熟化机制生长。     

超声辅助合成CeF3纳米晶及其表征

用超声波辅助法制备了CeF₃纳米晶.并用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线粉末衍射(XRD)、紫外吸收(UV)光谱和荧光光谱(PL)对纳米晶的结构与性能进行了表征.结果表明：超声时间对所制备的CeF₃纳米晶的形貌有很大的影响.随着超声时间的延长,所制备样品的形貌由“笼形”演变为规整的盘形.随着样品粒径的减小,纳米晶的紫外吸收峰和吸收带边发生明显的蓝移.纳米晶的荧光强度与纳米晶的结晶程度有关.     

ZnO纳米晶粉末和电沉积Ni薄层透射电镜样品的制备和观察

制备了ZnO纳米晶粉末和电沉积Ni镀层的透射电子显微镜样品,并利用透射电子显微镜对其进行了观察。     

不同形貌金纳米粒子的制备及其光谱特性

本文以柠檬酸三钠(Na3C6H5O7.2H2O)保护的小粒径金胶体为晶种,采用晶种法制备了不同形状的金纳米粒子。利用透射电子显微镜(TEM)和紫外可见光谱(UV-Vis)对所制备的金纳米粒子进行了表征。结果表明,随着晶种量的增加,金纳米粒子的形状依次为水滴状、梭状和球状,并且发现梭状金纳米粒子位于850nm处的多极共振吸收峰。基于表征结果分析了不同形貌产物的可能形成机理。     

纳米晶铜电火花电极快速制造及其耐电蚀性能(英文)

介绍了喷射电铸快速成形的基本原理,制备了纳米晶电极铜,分别研究了纳米晶铜电极和粗晶铜在不同电火花加工参数的工具电极损耗性能。运用扫描电子显微镜(SEM)和X-ray衍射等现代分析手段对工具电极的微观结构和成分进行分析。结果表明,喷射电铸能显著提高极限电流密度,细化晶粒,铜沉积层具有纳米晶微观结构。纳米铜电极损耗随着脉冲宽度增大而减小,随峰值电流的增大而增大,且纳米晶铜的电极损耗明显小于粗晶铜。     

银铜双金属纳米合金的制备和电催化性质

采用电沉积方法制备银铜双金属纳米合金,用X射线衍射仪（XRD）及高分辨率透射电子显微镜（HRTEM）,扫描电子显微镜（SEM）和电化学工作站分别对样品的结构、微观形貌和电催化性质进行了表征。结果表明,银铜双金属纳米合金电极在H₂O₂溶液中表现出较强的还原电流,可以作为阴极催化剂;随着银铜双金属纳米合金沉积电位的变负,阴极催化作用减弱,形貌由穗状晶向树枝晶转变;随着铜离子浓度的提高,阴极催化作用增强,银铜双金属纳米合金的形貌由树枝晶向棒状晶转变。这意味着,本文观察到了银铜双金属纳米合金的双金属电催化协同效应。     

Preparation and Tribological Behavior of BiIn/In_2O_3 Composite Dendritic Nanocrystals

BiIn/In2O3 composite dendritic nanocrystals were prepared by dispersing alloy droplets in paraffin oil. The morphology and structure of the alloy nanocrystals were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and X-ray powder diffraction (XRD). The composite nanocrystals have dendritic morphology, with an average diameter of 10 nm and lengths up to tens and even hundreds of nanometers. Tribological results indicate that the composite nanocrystals as oil additiv...     

硫化钨花形二维纳米晶的控制生长研究

以氧化钨为原料,硫化氢为气源在阳极氧化铝(AAO)模板基底上采用气固法制备出了硫化钨花形二维纳米晶体.采用x射线衍射(XRD)、电子透射显微镜(TEM)和场发射电子扫描显微镜(SEM)等手段对所制备的样品进行了检测分析,证实所得灰黑色产物是硫化钨单晶,片状单晶长宽约为几个微米,厚度约30nm.本文对纳米花晶体的制备、影响因素等进行了初步探讨.     

尖晶石结构Ni掺杂ZnFe2O4纳米颗粒的性能表征

利用水热法成功合成了纯ZnFe2O4和不同含量Ni掺杂Zn1-xNixFe2O4纳米颗粒。采用X射线衍射(XRD)、高分辨透射电子显微镜(HRTEM)、选区电子衍射(SAED)、X射线能量色散分析(XEDS)、紫外可见吸收光谱(UV-Vis)、傅里叶变换红外光谱(FT-IR)和振动样品磁强计(VSM)等测试技术研究掺杂浓度对Zn1-xNixFe2O4(x=0,0.1,0.3,0.5)样品的晶体结构、形貌、光学性能和磁学性能的影响。结果表明:所制备的Zn1-xNixFe2O4纳米颗粒结晶良好,Ni2+以替代Zn2+的形式掺杂到ZnFe2O4晶格中,生成立方尖晶石结构ZnFe2O4。随着Ni含量的增加,晶粒尺寸增大,晶格常数发生收缩。样品的形貌呈不规则的椭球形,且颗粒大小比较均匀。红外光谱的吸收峰位置并没有随Ni掺杂浓度的增加而变化。Zn1-xNixFe2O4纳米晶的光学带隙随Ni掺杂浓度增加而增大,与相应块体相比发生蓝移。在室温下,纯ZnFe2O4纳米晶呈现超顺磁性,掺杂样品具有明显的铁磁性。     

纳米二硫化钼的形态调控制备研究

采用沉淀法合成了不同形貌的MoS2纳米微晶.考查了煅烧温度、高分子分散剂对MoS2纳米微晶尺寸和形貌的影响,对合成的球状和棒状MoS2纳米微晶用粉末X射线衍射(XRD)和扫描电镜(SEM)进行了鉴定和表征.计算了不同煅烧温度下MoS2纳米微晶的晶粒度、微晶畸变参数,并结合扫描电镜(SEM)结果,初步探讨了不同形态二硫化钼纳米微晶生长的可能机理.     

Effect of Sulfur Precursor on Dimensions of One-dimensional CdS Nanocrystals

One-dimensional CdS nanocrystals have been prepared by solvothermal method using cadmium acetate as a cadmium precursor,elemental sulfur and Na2S,as a sulfur precursor,and ethylenediamine as a solvent at 150℃ for 5 h.The nanocrystals were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM) and UV-Vis absorption spectroscopy.XRD patterns indicate that both Na2S and elemental sulfur as the sulfur precursor result in CdS nanorods with wurtzite phase(h...     

Visible light induced electron transfer process over nitrogen doped TiO(2) nanocrystals prepared by oxidation of titanium nitride

Nitrogen doped TiO(2) nanocrystals with anatase and rutile mixed phases were prepared by incomplete oxidation of titanium nitride at different temperatures. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), core level X-ray photoelectron spectroscopy (CL XPS), valence band X-ray photoelectron spectroscopy (VB XPS), UV-vis diffuse reflectance spectra (UV-vis DRS), and visible light excited photoluminescence (PL). The photocatalytic activity was evaluated for photocatalytic degradation of toluene in gas phase under visible light irradiation. The visible light absorption and photoactivities of these nitrogen doped TiO(2) nanocrystals can be clearly attributed to the change of the additional electronic (N(-)) states above the valence band of TiO(2) modified by N dopant as revealed by the VB XPS and visible light induced PL. A band gap structure model was established to explain the electron transfer process over nitrogen doped TiO(2) nanocrystals under visible light irradiation, which was consistent with the previous theoretical and experimental results. This model can also be applied to understand visible light induced photocatalysis over other nonmetal doped TiO(2).     

Cu2O的室温液相法合成及光催化性能

采用简单的液相法在室温下制备了八面体与球形的Cu2O粉体,使用扫描电镜（SEM）、X射线衍射仪（XRD）和分光光度计对产物的形貌、晶相和光催化性能进行了检测。结果发现氢氧化钠在控制晶体粒径和形貌方面起到了非常重要的作用,球形Cu2O颗粒尺寸比八面体形貌的Cu/Cu2O小,并提出了不同形貌Cu2O可能的生长机制。研究了在可见光下,所得Cu2O粉在静止状态下对甲基橙溶液的光催化降解效果,结果表明,与八面体形貌的Cu/Cu2O复合材料相比,短时间内,小颗粒球形Cu2O对甲基橙有更高的脱色性能;但经长时间放置于日光中,发现八面体形貌的Cu/Cu2O具有更好的光催化降解性能。     

Fabrication and luminescent enhancement of Eu3+-doped Y2O3@YOF core-shell nanocrystals

In this paper, a two-step synthesis method for preparing Eu3+ ion-doped Y2O3@YOF core-shell nanocrystals is introduced. Eu3+ ion-doped Y2O3@YOF core-shell nanocrystals were prepared by combining an autocombustion process with a low temperature solid state reaction. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), photoluminescence (PL) and fluorescence decay were employed to characterize the prepared samples. The results of XRD, TEM and EDS indicated that the products prepared by this method were not a mixture of Y2O3:Eu3+ and YOF:Eu3+ nanocrystals, but Eu3+ ion-doped Y2O3@YOF core-shell nanocrystals. Compared with Y2O3:Eu3+ nanocrystals, a 20% increment in luminescence intensity was observed in the Eu3+ ion-doped Y2O3@YOF core-shell nanocrystals, thus suggesting that coating with a YOF:Eu3+-shell can efficiently block the nonradiative relaxation channels that are induced by surface defect states.     

Synthesis of Sb2E3 (E = S, Se) nanorods with a flat cross section by a rapid hot injection method

We report herein a simple colloidal synthesis route, i.e., rapid injection of E (E = S, Se) source into a hot solvent (1-octadecence, ODE) containing antimony precursor (antimony stearate), to grow Sb2E3 nanorods. The as-prepared nanorods were extensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). The mechanism for growth of Sb2E3 nanorods was also clarified from the view of crystal structure-directed growth. We believe that the method present here is a more straightforward and cost-effective route to prepare Sb2E3 nanocrystals with high quality.     

Solvothermal Synthesis and Characterization of Zinc Indium Sulfide Microspheres

ZnIn2S4 microspheres have been solvothermally prepared at 160℃ for 12 h with ZnCl2.2H2O,InCl3,and thiourea as the starting reagents in ethanol.The morphology,structure,and phase composition of the asprepared product were characterized by means of X-ray powder diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),X-ray photoelectron spectra(XPS),transmission electron microscopy(TEM),high-resolution TEM(HRTEM),and selected area electron diffraction(SAED).Results revealed that the prepared ZnIn2S4 microspheres were composed of sheetlike nanocrystals.The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm,respectively.A possible growth mechanism of the ZnIn2S4 nanosheet-built microspheres was proposed and briefly discussed.