水热法合成立方氮化硼微晶

低温低压条件下, 在水溶液中利用反应耦合效应成功地合成了立方氮化硼微晶. 利用X射线衍射(XRD), 傅里叶红外吸收(FTIR)测试确定了产物的物相组成, 根据透射电镜(TEM)和选区电子衍射(SAED)的测试结果分析产物的形貌和表面特征, 高分辨电镜(HRTEM)和X射线能谱仪(XPS)测试结果证明了立方氮化硼的存在.     

一种新BCN化合物先驱体的合成及其表征

以三聚氰胺和硼酸为原料在水溶液中反应合成了一种新的BCN化合物先驱体, 通过元素分析、XRD、FT-IR、电喷雾质谱及单晶X射线衍射对其进行了表征. 结构分析表明该化合物属单斜晶系, 化学式为C3H6N6(H3BO3)2, 是由C3H6N6分子和H3BO3分子通过氢键加合组装成的具有三维超分子结构的化合物. 将该先驱体在1900 ℃氮气气氛下热解, 对产物进行XRD和XPS表征, 结果表明得到了含碳量较低的具有乱层石墨结构的新型B3CN3化合物.     

球形SnO2 纳米微粒的合成及形成机理分析

以SnCl4*5H2O为主要原料,用溶剂热技术在油酸体系中成功地合成了球形SnO2纳米微粒,在无水乙醇体系中合成了菱形的SnO2纳米微粒.通过X射线粉末衍射(XRD),选区电子衍射(SAED)和透射电镜(TEM)对两种产物进行了表征,并对两种产物的形成机理进行了分析.透射电镜(TEM)结果表明: 在油酸体系中得到了平均尺寸约为 3.5 nm的球形SnO2纳米微粒,此微粒趋向于特殊高的比表面积,适合于作气敏探测器材料方面的应用.     

通过简单方法合成先驱体并利用电纺法制备BCN微米空心球

以三氯硼吖嗪(B3N3H3Cl3)和苯胺在N-甲基吡咯烷酮(NMP)溶剂中合成的聚合物为电纺液,由改进的电纺设备制备具有六方结构的BCN微米球。通过控制纺丝电压来控制BCN球体的直径。对其进行元素分析,并通过扫描电子显微镜,能量色散谱,X射线衍射和X射线光电子能谱进行表征。结果表明BCN微米空心球表面微凹,直径在10~30μm之间。硼碳氮间的比例约为1∶1.12∶0.94。     

纳米晶CuLa3Se5微波溶剂热合成及结构研究

采用微波溶剂热法合成纳米晶CuLa3Se5,具有快速,节能、纯度高、粒度小(平均粒径为20～30 nm)等优点.通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电镜能谱分析(EDS)和X射线光电子能谱(XPS)等手段表征其组成.讨论了微波溶剂热合成纳米晶的机制.漫反射紫外-可见吸收光谱(UV-Vis)表明标题化合物禁带宽度为2.27 eV,具有优良的半导体性能.     

Se和Se@C纳米棒的选择合成

通过调节葡萄糖浓度,采用十六烷基三甲基溴化铵(CTAB)辅助水热法选择合成了Se和Se@C纳米棒,并用扫描电镜(SEM)、透射电镜(TEM)、粉末X射线衍射(XRD)和X射线能谱分析(EDS)对产物进行了表征。结果表明,产物Se纳米棒直径200～300 nm,长达数微米;Se@C纳米棒长达数微米,内核直径200～00 nm,壳厚约30 nm。初步探讨了Se和Se@C纳米棒的生长机制。     

乙醇胺功能化石墨烯的制备与表征

乙醇胺在温和条件下与氧化石墨烯反应,然后经水合肼还原得到功能化的石墨烯.干燥的功能化石墨烯经超声处理后,可稳定分散于水、乙醇、丙酮和N,N二甲基甲酰胺(DMF)等溶剂中.原子力显微镜(AFM)、透射电镜(TEM)分析表明功能化石墨烯平均厚度为3～4 nm.傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPs)、X射...     

葡萄糖辅助合成碲化铅纳米棒及其表征

采用简单的葡萄糖辅助溶剂热合成法制备了碲化铅纳米棒。利用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、高分辨率透射电子显微镜(HRTEM)、能谱仪(EDS)等技术手段进行材料结构和形貌表征。结果表明,产物是纯的立方相Pb Te,纳米棒的直径约为50 nm,长500 nm左右。研究了反应过程的影响因素及碲化铅纳米棒的形成机制。产物的形貌受葡萄糖的量、反应时间、反应温度和聚乙烯吡咯烷酮(PVP)质量的控制,分析了形成这种结构的原因。     

溶胶凝胶法合成Li3V6O16及其电化学性能研究

本文以双氧水为配位剂,以CH3COOLi·2H2O和V2O5为原料,采用溶胶凝胶法合成了一种新型的晶体Li3V6O16。随后分别采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电子衍射(SAED)、X光电子能谱(XPS)和充放电测试等手段对材料进行了表征。SEM观察表明,产物主要是表面比较光滑的纳米片状晶体,TEM和SAED研究都证实了XRD和SEM的研究结果。充放电测试结果表明,该物质具有较高的比容量、良好的可逆性和循环稳定性。     

生物分子辅助溶剂热合成硫化锑纳米棒

以SbCl3和L-胱氨酸为反应原料,采用溶剂热法在170℃反应12h,制得硫化锑(Sb2S3)纳米棒.X射线衍射(XRD)、能量分散光谱(EDS)和X射线光电子能谱(XPS)研究表明所得产物为典型的Sb2S3正交结构.场发射扫描电子显微镜(FESEM)和透射电子显微镜(TEM)研究显示,Sb2S3纳米棒长为3～6μm,平均直径约为150nm.讨论了不同反应时间对Sb2S3的形成及其形貌的影响,并根据实验结果对所合成的一维纳米棒可能的形成机理进行了简单的探讨.     

Syntheses of CuO nanostructures in ionic liquids

A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.     

Preparation of novel saw-toothed and riblike alpha-Si3N4 whiskers

alpha-Si(3)N(4) whiskers with novel saw-toothed and riblike structures have been synthesized in a high yield by a carbothermal reduction and nitridation route. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). The results show that the saw-toothed whiskers with one smooth surface and another toothlike surface have lengths about several tens of microns and widths in the range of 600-1200 nm. The riblike whiskers are composed of Si(3)N(4) rod-arrays, which grow closely packed perpendicular to the central axial whiskers with uniform diameter and length. The growth mechanism of the products can be considered as a combination of VS mechanism and secondary epitaxial nucleation process. The photoluminescence (PL) spectrum of the whiskers shows a strong blue light emission peak at 406 nm and a weak peak at 485 nm, suggesting their potential applications in light and electron emission devices.     

Development of nanoscale inhomogeneities during drying of sol-gel derived amorphous lead zirconate titanate precursor thin films

The structural evolution of sol-gel derived lead zirconate titanate (PZT) precursor films during and after physical drying was investigated by transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), selected area electron diffraction (SAED), and time-resolved X-ray diffraction (XRD). Films were deposited from initial 0.3 mol/dm(3) precursor sols with varying hydrolysis ratios. Zr-rich grains of 1-10 nm size, embedded in a Pb-, Zr-, and Ti-containing amorphous matrix were found in as-dried films. The Zr-rich regions were crystalline at hydrolysis ratios [H(2)O]/[PZT] < 27.6, and amorphous at ratios > 100. X-ray diffraction analysis of PZT and zirconia sols revealed that the crystalline nanoparticles in both sols are identical and are probably composed of nanosized zirconium oxoacetate-like clusters. This study demonstrates that time-resolved X-ray diffraction combined with electron energy loss spectroscopy mapping is a powerful tool to monitor the nanoscale structural evolution of sol-gel derived thin films.     

特定条件下的定向ZnO纳米棒的制备及表征

采用改进的溶胶凝胶和化学溶液生长两步法,并控制特定条件在镀银载玻片上制备出定向ZnO纳米棒.利用X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、选区电子衍射（SAED）、能谱（EDS）及傅里叶红外吸收光谱（FTIR）对纳米棒的表面形貌、结构、组分进行分析.XRD和SEM结果表明该ZnO纳米棒具有六角纤锌矿...     

A simple method to synthesize polyhedral hexagonal boron nitride nanofibers

Hexagonal boron nitride (h-BN) fibers with polyhedral morphology were synthesized with a simple-operational, large-scale and low-cost method. The sample obtained was studied by X-ray photoelectron spectrometer (XPS), electron energy lose spectroscopy (EELS), X-ray powder diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), etc., which matched with h-BN. Environment scanning electron microscopy (ESEM) and transmission electron microscope (TEM) indicated that the BN fibers possess polyhedral morphology. The diameter of the BN fibers is mainly in the range of 100–500 nm.     

Nanobelt formation of magnesium hydroxide sulfate hydrate via a soft chemistry process

The nanobelt formation of magnesium hydroxide sulfate hydrate (MHSH) via a soft chemistry approach using carbonate salt and magnesium sulfate as reactants was successfully demonstrated. X-ray diffraction (XRD), energy dispersion X-ray spectra (EDS), selected area electron diffraction (SAED), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis revealed that the MHSH nanobelts possessed a thin belt structure (approximately 50 nm in thickness) and a rectangular cross profile (approximately 200 nm in width). The MHSH nanobelts suffered decomposition under electron beam irradiation during TEM observation and formed MgO with the pristine nanobelt morphology preserved. The formation process of the MHSH nanobelts was studied by tracking the morphology of the MHSH nanobelts during the reaction. A possible chemical reaction mechanism is proposed.     

Boron nanowires synthesized by laser ablation at high temperature

Boron nanowires have been synthesized by laser ablation at high temperature. The as-synthesized boron nanowires were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and electron energy loss spectroscopy (EELS). The boron nanowires have lengths of several tens of micrometers long and diameters of 30–60 nm. The effects of the synthesis conditions on the formation of the boron nanowires were investigated and possible growth mechanisms of the boron nanowires are discussed.     

Fine tuning of gadolinium doped ceria electrolyte nanoparticles via reverse microemulsion process

Gadolinium doped ceria (Gd–CeO₂) nanoparticles have been synthesized by an reverse microemulsion system using cyclohexane as the oil phase, a non-ionic surfactant Igepal CO 520 and their mixed aqueous solutions of gadolinium III nitrate hexahydrate and cerium III nitrate hexahydrate as the water phase. The control of particle size was achieved by varying the water to surfactant molar ratio. The synthesized and calcined powders were characterized by thermogravimetry-differential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD results show that all the samples calcined at 700 °C were single phase cubic fluorite structure. The average size of the particle was found to increase with increase in water to surfactant molar ratio (R). The mean diameter of the particle for various value of R varies between 8–15 nm (SEM) and 7.5–11 nm (TEM), respectively. EDS confirm the presence of gadolinia and ceria phase in the nanopowder calcined at 700 °C. FTIR analysis was carried to monitor the elimination of residual oil and surfactant phases from the microemulsion-derived precursor and calcined powder. Raman spectroscopy and DTA evidenced the formation of a solid solution of gadolinium doped ceria at room temperature.     

铂纳米空球的制备及其对甲醇氧化的电催化性能

以粒径为100nm的硒球作模板,在室温下批量合成了粒径约110nm、壳厚约5 nm的铂空球.采用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、高分辨透射电子显微镜（HR-TEM）、选区电子衍射（SAED）、X射线衍射（XRD）、能量色散X射线谱（EDX）等检测技术表征了其形貌与结构;以甲醇为探针分子研究了铂纳米空球修饰玻碳电极对甲醇电氧化的催化性能.结果表明,由铂原子簇团构筑的多孔铂空球粒径均匀、分散性好、结构稳定、比表面积大、传质性能好,是甲醇氧化的理想催化材料.循环伏安（CV）结果表明:当甲醇氧化的电流密度0.10 mA·cm^-2,正扫时,铂纳米空球的氧化电位与实心铂纳米粒子及铂黑相比,分别负移了约110和64mV;负扫时,前者比后两者分别负移了约51与13 mV.经800圈循环伏安扫描后,正扫时,甲醇在铂纳米空球上氧化峰的电流密度为实心铂纳米粒子及铂黑上的13和15倍;负扫时,前者为后两者的19和38倍.表明铂纳米空球对甲醇氧化具有较好的催化活性和稳定性.