Synthesis and Characterization of the Antibacterial Activity of Zinc Oxide Nanoparticles against Salmonella typhi

Metal oxides can be used as a series of new and effective anti-bacterial agents.In this study,four concentrations of ZnO nanoparticles(0.2,0.5,0.7 and 1.0 mol/L) were synthesized using a low-temperature sol-gel method annealed at400 and 550 °C.The products were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM)and Fourier transform infrared spectroscopy(FTER).XRD results show the hexagonal wurtzite structure of the nanoparticles with the grain size in the range of 38-43 nm.TEM micrographs exhibit a polyhedral form of the synthesized nanoparticles.The antimicrobial activity of different concentrations of nanoparticles against Salmonella typhi PTCC 1609 was determined by disk diffusion and agar dilution method at five concentrations of 10,5,2.5,1.25 and 0.625 mg/mL.Analysis shows that the prepared ZnO nanoparticles have a very effective antimicrobial activity against Salmonella typhi.This activity increases by reducing the size of nanoparticles and increasing their content in the bacterial growth medium.     

芦荟叶提取物绿色制备单分散纳米金及其性能研究

本文以芦荟叶提取液为还原剂和稳定剂,成功地制备了小粒径、球状的金纳米粒子。在这种方法中,简单的芦荟叶提取液和金源混合,没有使用有毒试剂,因此该方法是一种生态友好的合成纳米金的方法。混合溶液的颜色从浅黄色变到紫色,表明生成了纳米金粒子。采用紫外-可见吸收光谱(UV-vis)、激光粒径分析仪(DLS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)等方法对合成的纳米金粒子进行了表征和性能测试。紫外-可见光谱的吸收峰再次表明金纳米颗粒的形成。XRD分析表明所生成的纳米我金具有高度结晶性。TEM和SEM表明纳米金颗粒呈球形,粒径分布在20 nm到60 nm之间。FT-IR证实了金纳米粒子提取物所保护,使其不发生团聚和氧化。论文研究了反应温度、氯金酸溶液和提取物的用量对纳米金粒径的影响。结果表明,这些参数在金纳米粒子的合成中起着重要的作用。     

Generation of nanostructured CuO by electrochemical method and its Zn–Ni–CuO composite thin films for corrosion protection

Nanocrystalline copper oxide (CuO) powder of varying sizes (22, 25, 28 and 36 nm) have been successfully synthesized by hybrid electrochemical method using aqueous sodium nitrate electrolyte with Cu electrodes under galvanostatic mode at room temperature. The as‐synthesized CuO sample was calcined for an hour at temperatures ranging from 60 to 900 °C. The crystallite size, morphology, and chemical state of the synthesized powders were characterized by powder XRD, XPS, SEM/EDAX, TEM, and UV–Vis spectral methods. The effect of calcination temperature on crystallite size and morphology was studied. The TEM result revealed that, the particles are hexagonal and the sizes are in 30–50 nm in diameter and 120–200 nm in length. The band gap values are 5.60 and 5.54 eV. The crystallite size increased with increase of calcination temperature. The CuO nanopowder is used to fabricate Zn–Ni–CuO composite thin films and its corrosion behaviour was analysed by Tafel extrapolation and electrochemical impedance spectroscopy. The results indicate that the Zn–Ni–CuO composite thin films provided good corrosion protection.     

纳米Ag粒子与SiO_2复合薄膜的热稳定性

采用溶胶-凝胶法利用水解反应制备了纳米Ag粒子与SiO2复合的nano-Ag∶SiO2薄膜,通过对Ag纳米粒子局域表面等离子体共振(SPR)吸收光谱的观测,探讨了薄膜的热稳定性。利用TG-DSC、XRD、TEM、SEM和EDS等对nano-Ag∶SiO2的物性进行了研究。结果表明:nano-Ag∶SiO2薄膜在不同温度(200～900℃)下热处理,随着热处理温度的升高,薄膜中Ag纳米粒子的SPR特征吸收峰从无到有并逐渐增强,500℃、600℃峰值强度最强,然后逐渐减弱至消失;薄膜500℃热处理的热稳定性良好,复合纳米材料中SiO2为非晶态;当热处理温度升至700℃时,随退火时间的增加出现Ag纳米粒子扩散挥发的现象,并且SiO2由非晶态逐渐转变为晶态。     

Solvothermal synthesis and characterization of size-controlled Fe3O4 nanoparticles

Size-controlled Fe₃O₄ nanoparticles were prepared via a facile solvothermal method by using the mixed surfactants of SDS and PEG as protective reagents. The sizes of the nanoparticles can be varied from 15 to 190 nm by adjusting the experimental conditions. The influences of the protective reagents, reaction time, the initial concentration of the reactant, molar ratio of FeCl₃ and protective reagents on the size of the produced nanoparticles were studied. The size and morphology of the products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and scanning electron microscopy (SEM).     

Microwave-assisted synthesis and magnetic properties of size-controlled CoNi/MWCNT nanocomposites

Size-controlled CoNi alloy nanoparticles with average diameters in the range of 15-48 nm attached on the multi-walled carbon nanotubes (MWCNTs) were prepared to form CoNi/MWCNT nanocomposites by microwave-assisted method. The size of CoNi alloy nanoparticles can be controlled through adjusting the atomic ratios of metals to carbon nanotubes in the mixed acetate solution. The as-prepared nanocomposites have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), energy-disperse X-ray spectroscopy (EDS) and vibrating sample magnetometer (VSM). The results show that CoNi alloy nanoparticles are face-centered cubic structure, quasi-spherical and disperse uniformly on the surface of MWCNTs. Magnetic measurement shows that both the coercivity and the saturation magnetization of the samples increase with the increase of the particle size from 15 to 37 nm, and decrease from 37 to 48 nm.     

纳米复合材料CdS/TiO2NTs的制备及光催化产氢活性

通过离子交换和沉淀反应制备纳米复合材料CdS/TiO2NTs.采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、漫反射紫外-可见吸收光谱(DRUVAS)、荧光光谱(FES)、X射线荧光分析(XRF)等手段对该复合材料的结构进行表征.SEM结果表明:钛酸盐纳米管的形成经由TiO2颗粒-片状的钛酸盐-卷曲的钛酸盐纳米管的自组装过程.XRD、DRUVAS、FES和FES结果表明:平均粒度大约 8 nm 的六方相CdS均匀的负载于锐钛矿型TiO2纳米管表面,其吸收边扩展到可见区.与TiO2纳米管及TiO2粉末相比,CdS/TiO2NTs 纳米复合材料展示了较高的可见光催化分解水产氢活性.     

Fabrication of gold nanoparticles with different morphologies in HEPES buffer

Gold nanoparticles with different morphologies, such as spindle, octahedron, and decahedron were obtained by using different molar ratios of HAuCl4/HEPES in the presence and absence of surfactants at room temperature.These nanoparticles were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM), scanning electron microcopy(SEM), energy-dispersive X-rays analysis(EDX), and selected area electron diffraction(SAED).The kinetics o...     

Synthesis and optical studies of gamma irradiated Eu doped nanocrystalline CaF2

Europium (Eu) doped Calcium fluoride (CaF₂) nanoparticles are synthesized by co-precipitation method and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Also, optical absorption and photoluminescence (PL) results on gamma irradiated Eu doped CaF₂ nanoparticles are presented. The PXRD patterns confirmed the cubic crystallinity of the samples and the particle size is found to be ∼25 nm. The purity of the synthesized nanoparticles is confirmed from FTIR spectrum. The morphological features studied using SEM revealed that nanoparticles are agglomerated and porous. Optical absorption spectrum shows that γ-rayed Eu doped CaF₂ nanoparticles exhibit absorption bands at ∼279, 360 and 434 nm. The PL studies showed emission at ∼420, 525 and 552 nm.     

银纳米线的改进溶剂热法合成与表征

采用溶剂热法和晶种法相结合的改进方法,以硝酸银为银源,乙二醇为还原剂,聚乙烯吡咯烷酮为稳定剂和分散剂,制备银纳米颗粒晶种,进而在溶剂热环境中合成了高均匀性的银纳米线。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、和紫外-可见光分光光度计(UV-Vis)对产物的尺寸形貌、晶体结构以及光学性能进行了表征。结果表明,利用改进的溶剂热法制备的银纳米线具有较高的长径比,尺寸分布均匀,分散性良好,具有优异的等离激元共振吸收特性。     

Microwave-assisted solid-state decomposition of La[Co(CN)6]·5H2O precursor: A simple and fast route for the synthesis of single-phase perovskite-type LaCoO3 nanoparticles

Pure and single-phase nanoparticles of perovskite-type LaCoO₃ were prepared via microwave-assisted solid-state decomposition of La[Co(CN)₆]·5H₂O precursor in the presence of CuO powder as a strong microwave absorber within a very short reaction time of 10 min. Product was characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), Raman spectroscopy, UV–visible spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and surface area measurement. The method is simple, fast and energy efficient and resulted in fine particles (10–30 nm) with high specific surface area and narrow size distribution. This hybrid microwave heating route is promising for the synthesis of other mixed oxide and related compounds.     

氧化铜纳米棒/氧化石墨烯的制备及催化性能测试

氧化铜纳米棒/氧化石墨烯（CuO-NRs/GO）新型复合材料通过在氧化铜纳米棒上静电吸附氧化石墨烯而制备出来。通过XRD、TEM、SEM以及FT-IR对其结构和形貌进行了表征,并研究了其在超声条件下对罗丹明B的催化降解性能。结果表明：CuO-NRs/GO对罗丹明B有很好的催化降解性能。     

Ag-TiO2复合纳米颗粒的自组装法制备及其光催化性

采用空气-水界面自组装法制备TiO2纳米粒子,将其放入AgNO3溶液中浸泡,后在较低温度下进行热处理(400℃),获得Ag-TiO2复合纳米颗粒.利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、紫外可见光谱(UV-vis)等分析测试手段进行表征.结果表明:复合粒子可以显著提高TiO2颗粒光催化活性.以甲基橙为模拟污染物,经过光催化试验,证实复合纳米粒子具有较好的光催化活性,降解率达到96.25％.     

Electrochemical properties of NiO/Co-P nanocomposite as anode materials for lithium ion batteries

NiO/Co-P nanocomposite is prepared by an electroless cobalt plating technique. The as-prepared composite is characterized by means of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. SEM and TEM images reveal that the NiO particles are about 200 nm in size, which are modified by Co-P nanoparticles of about 30 nm. The electrochemical properties as anode materials for lithium ion batteries are examined by cyclic voltammetry (CV) and discharge-charge tests. The results show that, compared with the bare NiO without electroless cobalt plating, NiO/Co-P nanocomposite exhibits a smaller polarization and a better rate capability, which is attributed to the Co-P nanoparticles.     

Formation and Study of the Nanostructured CuAl0.5Ga0.5Te2 Synthesized by Mechanical Alloying Processing

Nanostructured chalcopyrite CuAl_0.5Ga_0.5Te₂ has been prepared by milling a mixture of reactants, copper, aluminum, gallium, and tellurium. The crystal structure, morphology, and composition of the prepared samples have been characterized by means of x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and transmission electron microscopy (TEM). X-ray diffraction has revealed the presence of the characteristic peaks of the chalcopyrite phase for the CuAl_0.5Ga_0.5Te₂-milled powders. The crystallite size and internal strain have been evaluated by XRD patterns using the Williamson–Hall method. The average particle size decreases as the milling time is prolonged, while the lattice parameters and internal strain increase. The TEM confirmed the formation of CuAl_0.5Ga_0.5Te_e nanoparticles. The bandgap has been found to increase from 1.42 eV up to 1.45 eV as the process time varies, respectively, from 60 min to 360 min.     

Synthesis of Gd_2O_3 nanoparticles:using bulk Gd_2O_3 powders as precursor

Gd2O3nanoparticles were synthesized from the commercial bulk Gd2O3 powders via a simple electrochemical method. The synthesized powders were characterized by means of X-ray powder diffraction(XRD),scanning electron microscopy(SEM), transmission electron microscopy(TEM) and Fourier transform infrared(FTIR) spectroscopy. The effects of solution p H on the morphological features of the sample were studied. The strategy developed in this study offers significant advantages for the synthesis of Gd2O3 nanoparticles from the bulk Gd2O3 powders compared with the conventional routes. From SEM observations, the size of the Gd2O3 nanoparticles is estimated to be significantly smaller than70 nm.     

纳米Ce/CuO的改性及室温脱硫性能研究

本文采用直接沉淀法制备出铁、钴和锌元素改性的纳米Ce/CuO脱硫剂,在室温常压条件下吸附含H2S恶臭气体,研究其脱硫活性。通过X射线衍射(XRD),透射电子显微镜(TEM),X射线光电子能谱(XPS)等技术分析了改性元素对纳米Ce/CuO脱硫剂结构的影响,探讨脱硫剂结构变化与脱硫性能的关系。结果表明,改性元素钴添加到纳米Ce/CuO脱硫剂中具有最好的脱硫活性,钴的添加使纳米Ce/CuO脱硫剂的粒径明显变小,材料中存在Cu3 ,且Cu3 /Cu2 的摩尔比值要高于纳米CuO和Ce/CuO样品,说明Co/Ce/CuO表面对脱硫反应有利的氧空位增加;当Co添加量为4.9%时,Co/Ce/CuO脱硫剂的穿透时间可达525min,比Ce/CuO脱硫剂的穿透时间延长了近300min。     

基于紫外光辐照法制备CuSe/ZnSe核壳结构纳米粒子

本文成功制备出以CuSe为核心、ZnSe为壳层,具有核壳结构的CuSe/ZnSe纳米粒子。首先采用回流冷凝法制备出CuSe纳米粒子（NPs）。然后,采用一种简单、快速的光化学方法即紫外光辐照法,室温下在CuSe NPs外包覆ZnSe壳层,最终得到CuSe/ZnSe核壳结构纳米粒子。利用X射线衍射(XRD)、能量色散谱仪(EDS)、透射电镜(TEM)、高分辨透射电镜(HRTEM)和光致发光光谱(PL)对合成的CuSe/ZnSe核壳NPs进行了表征。结果分析表明,合成的CuSe纳米粒子具有六方相结构,粒径平均大小在12 nm。制备出的CuSe/ZnSe纳米粒子的核壳结构清晰,生长的ZnSe壳层为立方闪锌矿结构,粒径大小约为15~45 nm。通过ZnSe壳层的包覆使CuSe在475 nm处产生蓝光发射,同时荧光强度显著增强。     

Obtaining YSZ nanoparticles by the sol–gel method with sucrose and pectin as organic precursors

Production of yttria-stabilized zirconia (YSZ) nanoparticles with the sol–gel method using new organic precursors: sucrose and pectin, which are abundant and cost effective, is described. Different analyses of the produced nanoparticles are presented. The crystal structure is analyzed by X-ray diffraction (XRD). The sintering process is studied by thermal analysis (TA), and suggestions are made for processes responsible for the exo- and endothermic weight losses seen in the TA profiles. The particle size is determined by transmission electron microscopy (TEM), supported by XRD-determination of the crystallite size using the Scherrer formula, and the Brunauer, Emmet, and Teller (BET) adsorption analysis used to determine the specific surface area. All the analyses give consistent results, and show nanoparticles of a fairly uniform, small size, with a cubic crystal structure, and fully of the same quality as is produced using the known organic precursors.     

纳米植酸锌缓蚀效果及其复合环氧涂层的防护性能

目的 考察NaCl溶液中植酸锌对Q235的缓蚀效果及其复合环氧涂层的防护性能。方法 以植酸钠和乙酸锌为原材料成功制备纳米植酸锌,并通过红外光谱仪（IR）、扫描电子显微镜（SEM）、电子能谱仪（EDS）、透射电子显微镜（TEM）及X射线衍射仪（XRD）对其结构及形貌进行表征。采用开路电位、极化曲线、X射线光电子能谱技术（XPS）及SEM等手段,研究了Q235在含植酸锌浸出物的Na Cl溶液中的腐蚀行为及腐蚀形貌。利用SEM、电化学阻抗谱（EIS）以及盐雾测试等方法,研究了纳米植酸锌在环氧涂层中的分散性及其对环氧涂层防腐蚀性能的影响。结果 SEM和TEM显示合成的植酸锌为球形颗粒,颗粒直径较为均匀,为20～40 nm。开路电位、极化曲线测试显示,纳米植酸锌浸出物可以抑制Q235在1%NaCl溶液中的腐蚀。XPS显示,Q235试样表面明显吸附植酸根成膜。纳米植酸锌在环氧树脂中的分散状态良好,无明显团聚现象。EIS和盐雾测试显示,纳米植酸锌可以增强环氧涂层的防护性能。结论 纳米植酸锌可以用作防锈颜料,且相比于磷酸锌防锈颜料,添加相同量的纳米植酸锌的涂层的防腐效果更佳,其可能和植酸锌的小尺寸、良...