Bi2Se3纳米片的制备及表征

以BiCl3和Se粉为铋源和硒源,Na2SO3为还原剂,在碱性条件下,采用简单的溶剂热法首次在不同溶剂中均合成了Bi2Se3纳米片.探究了不同反应时间片状纳米晶的定向生长特性.通过X射线粉末衍射 (XRD )仪,扫描电子显微镜 (SEM),X射线能谱仪 (EDS),透射电子显微镜 (TEM) 和高分辨透射电子显微镜 (HRTEM) 等方法对所得产物的物相结构及形貌进行了表征.结果表明在不同溶剂中所得产物均为纯六方相Bi2Se3纳米片,产物的尺寸及形貌随溶剂变化虽有所不同,但总体为片状形貌,并阐明了片状形貌Bi2Se3的形成与其内部特殊的层状结构密切相关.     

三硫化二铋纳米棒回流法合成研究

以硫代乙酰胺和氯化铋为原料、聚乙二醇800为表面活性剂、1,2-丙二醇为溶剂,采用常压回流法在187 ℃下反应6 h,制备了尺寸均匀且具有较高长径比的三硫化二铋(Bi2S3)纳米棒.X射线衍射结果表明:所制备的产物是正交Bi2S3晶相,其晶胞参数为:a=1.081 3 nm,b=1.125 8 nm,c=0.394 0 nm.通过场发射扫描电子显微镜、选区电子衍射、透射电子显微镜表征表明:所制备的三硫化二铋纳米棒为单晶且沿[001]晶面生长,其端面直径约80 nm,长约1 μm.对三硫化二铋纳米棒的生长机理也进行了探讨,并考察了反应介质、硫源及表面活性剂的不同对晶体形貌的影响.     

纳米结构Bi_2S_3的制备及其发光特性

以硝酸铋和硫化钠为原料,用两步水热法于100℃成功制备了正交晶系Bi2S3微米环:又以硝酸铋和硫脲为原料,采用一步水热法于150℃ 制备了同属于正交晶系的Bi2S3纳米棒.分别以X射线衍射仪、场发射扫描电镜,透射电子显微镜和荧光分光光度法等测试手段对最终产物的物相、形貌和性质进行了表征,探讨了Bi2S3微米环的形成机理.结果表明:Bi2S3微米环的内径为1～1.5μm、外径为1.5～2μm,由均尺寸大约为100m 的纳米晶粒组装而成.Bi2S3纳米棒的直径约125nm、长度为1～2 μm.Bi2S3微米环和纳米棒状Bi2S3的发光峰分别位于447nm处和470nm处,Bi2S3 微米环发光峰的位置相比于Bi2S3纳米棒的发光峰位置明显发生了蓝移.     

硫化铋准纳米带阵列的可控合成及光学性质

以五水硝酸铋和硫脲为原料,采用籽晶技术和水热相结合的方法,在涂籽晶层的硅片上制备了大面积Bi2S3准纳米带阵列。利用X射线衍射、场发射扫描电子显微镜、透射电子显微镜、高分辨透射电子显微镜和电子衍射等对产物的结构和形貌进行表征。结果表明,合成产物为纯正交相的纯Bi2S3,纳米带阵列中的纳米带宽约为130 nm,长约2μm,并且沿[130]方向优先生长。使用涂有Bi2S3纳米籽晶的衬底是生长大规模准纳米带阵列的必要条件,衬底在高压釜中放置高度影响产物的形貌。Bi2S3准纳米带阵列的形成机理与自组装生长和Bi2S3的各向异性生长相关。产物的荧光光谱为从650nm到800nm的红光区域宽发光带,是由Bi2S3准纳米带阵列结构中的复杂缺陷导致的。     

多级四角枝形钯纳米晶的控制合成及其电催化性能

以乙酰丙酮钯为前驱体,聚乙烯吡咯烷酮(PVP)为稳定剂,N,N-二甲基甲酰胺(DMF)为溶剂,一氧化碳为还原剂,在一定量甲酰胺的存在下,控制CO的流速,100℃油浴加热3 h,可以得到形貌单一的四角枝状Pd纳米晶,单枝呈多级结构特征。利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X-射线粉末衍射(XRD)、X-射线光电子能谱(XPS)对其结构进行表征。所合成的多级四角枝Pd纳米晶对甲酸的电催化氧化活性约为商业Pd黑的2.6倍。     

硫化铋单晶纳米棒的回流法合成与表征

以三氯化铋(BiCl3)和硫代乙酰胺(CH3CSNH2)为原料,以乙二醇为反应介质,聚乙二醇为表面活性剂,采用回流法合成了硫化铋单晶纳米棒.所得产物用x射线粉末衍射、透射电子显微镜、场发射扫描电子显微镜、高分辨电子显微镜进行了表征,结果表明:在乙二醇体系中197℃下回流反应12小时,可得到具有较大长径比的硫化铋单晶纳米棒,并考察了反应介质、铋源和反应时间的变化对所制备样品形貌的影响.     

硫化亚铜薄膜的生物合成及表征

以生物蛋壳为内反应器,氯化铜和硫脲为原料,通过水热法在铜丝网上合成了硫化亚铜薄膜样品。用X射线粉末衍射仪(XRD)和扫描电子显微镜(SEM)表征分析表明,产品为纯相Cu2S,形貌为纳米棒。同时,对影响Cu2S纳米棒生物合成的因素作了讨论。     

稀土氢氧化镝纳米棒的水热合成及生长机理研究

本文介绍了一种水热合成稀土Dy(OH)3纳米棒的方法,反应条件温和,绿色环保,无污染.在水热过程中,以氧化镝粉末为反应前驱体,氢氧化钾为矿化剂,水为溶剂,180℃条件下水热48 h,合成了稀土Dy(OH)3纳米棒,再经过500℃热处理1h,即可得到同形貌的Dy2O3纳米材料.通过X射线粉末衍射(XRD)仪、透射电镜(TEM)对样品进行表征,结果表明,所制得的稀土Dy(OH)3为结晶良好、粒径均一、表面光滑的棒状纳米结构.同时,本文对矿化剂对产物形貌的影响进行了探讨.     

表面活性剂CTAB辅助溶胶–凝胶法制备硼酸铝纳米棒

以仲丁醇铝(aluminum tri-sec-butoxide,ATSB)和硼酸为原料,采用阳离子表面活性剂(cetyltrimethyl ammonium bromide,CTAB)辅助溶胶–凝胶法于120℃形成白色干凝胶,再进行焙烧得到硼酸铝纳米棒。采用X射线衍射仪、扫描电子显微镜、透射电子显微镜、X射线能量色散谱仪和Fourier变换红外光谱仪对产物结构和形貌进行表征。结果表明:750℃焙烧产物为具有单晶结构的Al4B2O9纳米棒,,其形貌及直径、长度受ATSB和硼酸摩尔比影响;当ATSB与H3BO3摩尔比为1:2时,Al4B2O9纳米棒直径约为15nm,长度为200～300nm。1200℃焙烧的产物为Al18B4O33纳米棒,其直径为200～500nm,长度约为3μm。对硼酸铝纳米棒的形成机理进行了初步探讨。     

Al掺杂ZnO纳米棒在柔性衬底上的生长及其性能研究

利用水热法在PET-ITO柔性衬底上制备铝(Al)掺杂的ZnO纳米棒(ZnO∶Al)。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、I-V特性测试等分析了合成纳米材料的微观形貌、晶体结构、电学性能。结果表明,掺杂Al时对ZnO纳米棒生长有直接的影响。构建了添加Alq_3为绝缘层的PET-ITO/ZnO纳米棒/Alq_3/AgMIS(金属M-绝缘体I-半导体S)器件,并对其电学性能深入研究,实验表明该器件对整流特性有良好反应。     

L-胱氨酸辅助合成纳米片状硫化铋

以L-胱氨酸为硫源和结构导向剂,采用L-胱氨酸辅助合成法制备了样品Bi_2S_3.X射线衍射分析表明:所合成的产物为正交相Bi_2S_3,其晶胞常数为a=1.1141 nm,b=1.1304nm,c=0.397 8nm.由X射线光电能谱的分析得知Bi与S的摩尔比为2.0:2.9.利用场发射扫描电子显微镜对所合成的产物的表面形貌进行了表征,结果表明:所合成的Bi_2S_3为排列规整的纳米片状结构,片厚约20nm;反应时间对Bi_2S_3的结晶性和形貌控制有着非常重要的影响.最后对所合成的Bi_2S_3的形成机理进行了探讨.     

电沉积法制备Bi_2S_3薄膜及其生长机理

采用阴极恒电压电沉积法在氧化锡铟透明导电玻璃表面沉积了Bi2S3薄膜,用X射线衍射、X射线光电子能谱仪、原子力显微镜、场发射扫描显微镜对制备薄膜的结构和形貌进行了表征。通过对不同沉积时间下制备薄膜的表面形貌分析,初步探讨了电沉积法制备Bi2S3薄膜的生长机理。结果表明:所制备的薄膜由正交相Bi2S3组成,无杂质相;薄膜表面形貌呈现出沿c轴取向的竹笋状的三维结构;随着沉积时间延长,薄膜结晶性能先提高后下降;其生长模式是基于电场力对离子的作用而诱导产生的垂直于基板方向的层状生长。     

Facile one-pot synthesis of polytypic CuGaS2 nanoplates

CuGaS₂ (CGS) nanoplates were successfully synthesized by one-pot thermolysis of a mixture solution of CuCl, GaCl₃, and 1-dodecanethiol in noncoordinating solvent 1-octadecene. Their morphology, crystalline phase, and composition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. Crystalline structure analysis showed that the as-prepared CGS nanoplates were polytypic, in which the wurtzite phase was interfaced with zincblende domains. The growth process of CGS nanoplates was investigated. It was found that copper sulfide nanoplates were firstly formed and then the as-formed copper sulfide nanoplates gradually transformed to CGS nanoplates with proceeding of the reaction. The optical absorption of the as-synthesized CGS nanoplates was also measured and the direct optical bandgap was determined to be 2.24 eV.     

Selected-Control Synthesis and the Phase Transition of Fe3O4 and α-FeOOH in Ethanol/Water Media

Fe₃O₄ nanoparticles and α-FeOOH nanorods with tunable size have been selected control synthesized via a facile hydrothermal process in the presence of CTAB. By means of adjusting the volume ratio of ethanol/water media at three levels: 0 (in which water was used as a solvent alone), 2:3, and 4:1, phases of the products transformed from Fe₃O₄ into α-FeOOH gradually. X-ray powder diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize the as-synthesized samples. The related mechanisms of phase transformation are discussed.     

Fe2O3中空微球的制备与表征

以自制碳球为模板,FeCl3为原料,经水解、高温煅烧,制备出粒径约为250 nm的Fe2O3中空微球。用X-射线衍射（XRD）、透射电镜（TEM）等现代测试手段对Fe2O3中空微球样品的结构、形貌进行了表征;并考察了煅烧时间的变化对所制备的Fe2O3中空微球的晶型及形貌的影响。     

Synthesis of Single Crystalline Hematite Polyhedral Nanorods Via a Facile Hydrothermal Process

Single-crystalline α-Fe₂O₃ nanorods with a polyhedral configuration have been successfully synthesized via a facile hydrothermal process at 180°C. X-ray powder diffraction, transmission electron microscopy observations, field emission scanning electron microscopy, and selected area electron diffraction patterns were used to characterize the as-synthesized samples. The result reveals that goethite nanorods were first generated and then transformed into hematite via dehydration in the successive hydrothermal treatment, in which the α-Fe₂O₃ inherited the rod-like morphology of the goethite precursor. The effect of surfactant and treatment time on the phase and morphology of the final products has been studied, and a possible growth mechanism is proposed.     

液相化学还原法制备纤维状纳米镍

采用液相化学还原法,利用醋酸镍为母体,1,2-丙二醇为还原剂,氢氧化钠为pH调节剂,以表面活性剂聚乙二醇-6000(PEG-6000)为修饰剂,在1,2-丙二醇体系中合成了纤维状多晶纳米镍。通过X射线衍射(XRD)、透射电子显微镜(TEM)、选区电子衍射(SAED)对所制备的样品进行了表征。通过傅立叶红外仪(FTIR)分析初步解释了纤维状纳米镍的形成机理。     

层状溶致液晶中纳米羟基磷灰石的合成

在一定的pH值条件下,将Ca(NO3)2和(NH4)2HPO4分别溶于C34H62O11(聚乙二醇辛基苯基醚)/C8H17OH/H2O体系层状溶致液晶溶剂层中,混合并经陈化即可在溶剂层中生成具有一定微观形貌的羟基磷灰石纳米粒子(HA),其直径可以达到10 nm,长度在100 nm以下.产物在不同温度下焙烧,分别用FTIR,XRD和TEM等对产物的结构及形貌进行分析表征.对不同反应物浓度条件下所得HA的微观形貌进行分析对比,并提出了改善团聚的有效措施.     

Hot pressing sintering of zinc sulfide microsphere decorated with nanorods synthesized by the simple refluxing method

A zinc sulfide microsphere decorated with nanorods was synthesized using the refluxing method. Then, the as-obtained ZnS nanostructures were consolidated via the hot pressing (HP) technique. X-ray diffraction, Fourier transforms infrared spectroscopy, high-resolution transmission electron microscopy, field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy, and X-ray mapping analyzes were used to characterize the ZnS sample. The effects of various factors such as pH, temperature, and reaction time were investigated on the morphology and particle size of ZnS nanostructures. The formation of sphalerite phase of ZnS nanoparticles was confirmed by the XRD analysis. FESEM also revealed that ZnS nanostructures with the molar ratio 1:1.3 (zinc: sulfur) had a spherical morphology decorated with sulfur nanorods. The ZnS nanostructures were consolidated by hot pressing technique at 860 °C for 2h under vacuum atmosphere. XRD analysis indicated that the sintered ceramic had a sphalerite phase. FESEM study demonstrated that ZnS ceramic had a grain size diameter within the range of 1–3 μm.