共查询到20条相似文献,搜索用时 31 毫秒
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Jun Wang Shanshan He Zhanshuang Li Xiaoyan Jing Milin Zhang Zhaohua Jiang 《Colloid and polymer science》2009,287(7):853-858
CuO shuttle-like and flower-like nanocrystals were synthesized through a one-step, low-temperature solution-phase method in
the presence of a cation surfactant, hexadecyl trimethyl ammonium bromide. These nanocrystals were studied as an additive
for promoting the thermal decomposition of ammonium perchlorate (AP). With the addition of CuO shuttle-like and flower-like
nanocrystals, the thermal decomposition temperature of AP decreased. The structure, particle size, and morphology of resulting
CuO powders were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Thermogravimetric
analysis technique was applied to investigate the thermal decomposition of mixtures of AP and as-prepared CuO nanocrystals. 相似文献
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Bowen Xue Zhongwen Qian Chunsheng Liu Genxiang Luo 《Russian Journal of Applied Chemistry》2017,90(1):138-143
Sphere-like CuO products aggregated by numerous nanoparticles were fabricated by a low-temperature (50°C) wet chemical method using CuSO4·5H2O as precursor. The possible formation processes of CuO were investigated by a series of single-factor experiments. The CuO was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, selectedarea electron diffraction. Furthermore, the application of CuO nanoparticles on the thermal decomposition of ammonium perchlorate was studied with 2 wt % CuO nanoparticles at heating rates of 10, 15, 20, and 25°C min–1 from 35 to 500°C. 相似文献
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Seyed Ghorban Hosseini Mohammad Ali Zarei Seyed Jafar Hosseini Toloti Hamid Kardan Mohammad Amin Alavi 《Journal of Thermal Analysis and Calorimetry》2018,131(2):925-935
In this research, ultrasound irradiation as a simple method was used to produce boron nanostructures. Reaction conditions such as boron concentration and sonication time show important roles in the size, morphology and growth process of the final products. The boron nanostructures (nanoparticles and nanorods) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, small-angle X-ray scattering and inductively coupled plasma atomic emission spectroscopy techniques. Primary evaluation of results showed that nanoparticles and nanorods of boron successfully have been prepared with 25–40 and 50–100 nm average particle size, respectively. These nanostructures (nanoparticles and nanorods) were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP) particles. Thermochemical decomposition behaviors of treated samples were characterized by thermal gravimetric analysis and differential scanning calorimetry techniques. Also, the kinetic parameters of thermal decomposition processes of pure and treated samples were obtained by nonisothermal methods proposed by Kissinger and Ozawa. However, boron nanoparticles with the smallest average particle size (25–40 nm) have the most significant catalytic effect including the decrease in decomposition temperature of AP + B nanocomposite by 100 °C, increase in the heat of decomposition from 580 to 1354 J g?1 and decrease in activation energy from 207 to 110 kJ mol?1. 相似文献
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Wang Li Zhao Bin Yuan ZhongYong Zhang XueJun Wu QingDuan Chang LiXian Zheng WenJun 《中国科学B辑(英文版)》2007,50(1):63-69
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. 相似文献
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Porous CuO superstructure: precursor-mediated fabrication, gas sensing and photocatalytic properties
A facile route was developed for the large-scale preparation of porous CuO superstructures based on a hydrothermal route with subsequent calcination. The CuO superstructures show "box-like" shape and are composed of microplatelets with high porosity resulting from the thermal decomposition of the precursor. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform spectroscopy (FT-IR) and Brunauer-Emmett-Teller N(2) adsorption-desorption analyses were employed to characterize the microstructure, size and crystalline phase of the porous cupric oxide product. The porous CuO superstructures with pore size of about 20 nm have a surface area of 18.2 m(2)/g. The gas-sensing measurements of the porous CuO superstructures demonstrate that the obtained CuO product exhibits higher sensing response to ethanol, propanol and acetone than commercial CuO powder. In addition, the enhanced photocatalytic activity of the porous CuO superstructures was also demonstrated with the photocatalytic degradation of methylene blue as a probe reaction. It is believed that the enhanced gas-sensing and catalytic properties are originated from their unique openly porous microstructure, which is highly beneficial to the reagent diffusion and mass transportation. 相似文献
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Hierarchical flower-like architectures of[Ni3(BTC)2·12H2O](BTC3=benzene-1,3,5-tricarboxylate) were successfully prepared by a simple solution-phase method under mild conditions without any template or surfactant.Phase-pure porous NiO nanocrystals were obtained by annealing the Ni-BTC complex without significant alteration in morphology.The product was characterized by X-ray diffraction techniques,field-emission scanning electron microscopy(FESEM).transmission electron microscopy(TEM) and high-resolution TEM(HRTEM).The catalytic effect of the NiO product was investigated on the thermal decomposition of ammonium perchlorate(AP) and it was found that the annealed NiO product has higher catalytic activity than the commercial NiO. 相似文献
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CuO nanocrystals of different surface areas were prepared. All samples were characterized by X-ray diffraction, transition
electron microscope, thermogravimetry, Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, and Raman
spectroscopy. CuO nanocrystals showed a stable monoclinic structure. With increasing surface areas, the surface hydration
became significant, which is followed by shifts in infrared frequencies and Raman phonon modes. CuO nanocrystals were explored
as an additive to catalytic decomposition of ammonium perchlorate (AP). AP decomposition underwent a two-stage process. Addition
of CuO nanocrystals led to a downshift of high-temperature stage towards lower temperatures. 相似文献
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Guorong Duan Junwu Zhu Chun Kan Xujie Yang Lude Lu Xin Wang 《Reaction Kinetics and Catalysis Letters》2007,92(2):247-256
For the first time, novel structural nanosized Y2O3 powders were successfully synthesized by the n-butanol soft-template method. X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Raman
spectroscopy were used to characterize the products. The results indicate that these products (calcined at 700°C) were comprised
of many Y2O3 nanomembranes, and the nanomembranes could change into nanorods when calcined at 1000°C. Interestingly, differential thermal
analysis studies suggested that the nanosized Y2O3 crystals had intense catalytic activity on the thermal decomposition of ammonium perchlorate. 相似文献
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A simple solution route was developed to fabricate monodisperse wurtzite ZnO nanorods. The as-prepared samples were 5 ??m in length and 70?C100 nm in diameter. The crystallinity, morphology, and structure of the rod-like ZnO microcrystals were examined. The crystal phases and the microstructure of the nanorods were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Room- and low-temperature photoluminescence (PL) and Raman spectra were employed to investigate the surface states of the samples. The deep-level emission band was barely observable at both room and cryogenic temperatures. 相似文献
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In the present paper a pure phase of the copper chromite spinel nanoparticles (CuCr2O4 SNPs) were synthesized via the sol–gel route using citric acid as a complexing agent. Then, the CuCr2O4 SNPs has been characterized by field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). In the next step, with the addition of Cu–Cr–O nanoparticles (NPs), the effects of different parameters such as Cu–Cr–O particle size and the Cu/Cr molar ratios on the thermal behavior of Cu–Cr–O NPs + AP (ammonium perchlorate) mixtures were investigated. As such, the catalytic effect of the Cu–Cr–O NPs for thermal decomposition of AP was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA/DSC results showed that the samples with different morphologies exhibited different catalytic activity in different stages of thermal decomposition of AP. Also, in the presence of Cu–Cr–O nanocatalysts, all of the exothermic peaks of AP shifted to a lower temperature, indicating the thermal decomposition of AP was enhanced. Moreover, the heat released (ΔH) in the presence of Cu–Cr–O nanocatalysts was increased to 1490 J g−1. 相似文献
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以Gd2O3、H3PO4为原料,聚乙二醇(PEG)为结构导向剂,通过改变沉淀剂NaOH的用量,制备了棒状、丝状的GdPO4纳米粒子,用X射线衍射仪(XRD)、X射线能量扩散光谱仪(EDS)、透射电子显微镜(TEM)、X射线光电子能谱仪(XPS)、富里叶变换红外光谱仪(FT-IR)对样品进行表征,研究了样品的激光拉曼散射光谱(Raman)、光致发光(PL)性质。结果表明,两种不同形貌的GdPO4纳米粒子具有不同的光学活性,PEG的浓度以及它和Gd3+、H+的配位作用对棒状GdPO4纳米粒子的形成有重要的影响。 相似文献
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L. -J. Chen G. -S. Li P. Qi L. -P. Li 《Journal of Thermal Analysis and Calorimetry》2008,92(3):765-769
This work reported on the thermal decomposition of ammonium perchlorate activated by addition of NiO nanocrystals with different
surface areas. NiO samples were characterized by X-ray diffraction (XRD), transition electron microscope (TEM), Brunauer-Emmett-Teller
(BET) technique, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. With increasing annealing temperature,
the surface areas of NiO samples reduced from 108.6 to 0.9 m2 g−1. The catalytic activities of NiO nanocrystals on the thermal decomposition of ammonium perchlorate were investigated by thermogravimetric
analysis (TG) coupled with differential thermal analysis (DTA). With addition of NiO nanocrystals, thermal decomposition temperature
of AP decreased greatly. Larger surface areas of NiO nanocrystals promoted the thermal decomposition of AP. 相似文献
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Ji-Min Yang 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(7):1214-1220
Ni(II)-doped Zn-based coordination polymer particles (Ni(II)-doped Zn-CPPs) with controllable shape and size were successfully synthesized by solvothermal method, which further transformed to porous ZnO–NiO composite micropolyhedra without significant alterations in shape by calcination in air. Those products were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), infrared spectroscopy (IR) and gas adsorption measurements. The catalytic activity of ZnO–NiO composites for the thermal decomposition of ammonium perchlorate (AP) was investigated. The result shows that all ZnO–NiO composites efficiently catalyzed the thermal decomposition of AP, and NiO–ZnO composite hollow octahedrons have the highest catalytic efficiency compared with that of most materials reported to now, indicating that porous ZnO–NiO composite micropolyhedra could be a promising candidate material for application in AP-based propellant. 相似文献
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以CuSO4和NH3·H2O为原料,采用微乳-均匀沉淀耦合法制备了一维CuO纳米棒。用XRD、SEM、TEM、HRTEM和FTIR对产物的结构和形貌进行了表征。结果表明:产物为单斜晶相结构的CuO纳米棒,内部具有孔洞结构,其直径为40~110nm,长度为800~3000nm。可通过改变水核比(ω)、反应物的浓度、反应时间、反应温度等条件实现对CuO纳米棒形貌和尺寸的调控。探讨了可能的反应机理,并用热分析方法考察了CuO纳米棒对高氯酸铵(AP)分解的催化作用。 相似文献
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Guo Z Chen X Li J Liu JH Huang XJ 《Langmuir : the ACS journal of surfaces and colloids》2011,27(10):6193-6200
ZnO/CuO heterohierarchical nanotrees array has been prepared via a simple hydrothermal approach combined with thermal oxidation method on Cu substrates. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometer(XRD) are employed to characterize and analyze the as-synthesized samples. The results demonstrate that the secondary growth of ZnO nanorods enclose with CuO nanowires, leading to the formation of ZnO/CuO heterohierarchical nanotrees array. The hierarchical nanostructures have isotropic crystal symmetry and they have no 6-fold (or 4-fold or 2-fold) symmetry as general epitaxial growth. Enlightened by the similarity with microstructure of lotus, the wettability of ZnO/CuO heterohierarchical nanotrees array has been investigated. It is revealed that as-prepared ZnO/CuO nanotrees array after silanization present remarkable superhydrophobic performance, which is attributed to the trapped air and hierarchical roughness. Furthermore, their wettability could be manipulated by the morphologies of hierarchical ZnO nanorods. At the optimal condition, the greatest static angle of water droplet on the obtained heterohierarchical nanotrees array could reach almost 170°, and this substrate could be used as self-cleaning surface. 相似文献
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Chira R. Bhattacharjee Debraj Dhar Purkayastha Nirmalendu Das 《Journal of Sol-Gel Science and Technology》2013,65(3):296-300
Tricobalt tetraoxide nanoparticles have been successfully synthesized following a ‘bottom-up’ approach by surfactant-free thermal decomposition of cobalt(II)-tartrate complex obtained by a modified sol–gel route. The synthesized complex was characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental and thermogravimetric-differential thermal analysis (TG–DTA). The nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman studies. The powder XRD pattern furnished evidence for a face-centered cubic structure of Co3O4. With the rise in calcination temperature from 400 through 500 to 600 °C, the average crystallite sizes of Co3O4 were found to increase from 28 through 36 to 46 nm. The TEM image revealed a faceted morphology of the as-synthesized Co3O4 nanoparticles. The high-resolution TEM image indicated the interplanar separation to be 0.28 nm which corresponds to the (220) plane in face-centered cubic Co3O4. The electron diffraction (ED) pattern showed single-crystalline nature of the synthesized nanoparticles. Raman spectrum showed four characteristic peaks of Co3O4 which further confirmed the phasic purity of the material. 相似文献
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The ternary semiconductor CdIn(2)S(4) nanorods were synthesized by a method based on CdS nanorods via the hydrothermal route, in which CdS nanorods were converted by reaction with InCl(3) and thiourea in aqueous solution. Transmission electron microscopy (TEM) images revealed that the typical sizes of the CdIn(2)S(4) nanorods were 10-30 nm in diameter and 200-1000 nm in length. X-ray photoelectron spectra (XPS) analysis of the surface stoichiometry (CdIn(2.03)S(4.15)) and room-temperature Raman spectrum (RS) were recorded. The influences of reaction temperature, time, and sulfur sources on the formation for CdIn(2)S(4) nanorods were investigated. A possible formation mechanism of the CdIn(2)S(4) nanorods was also proposed. 相似文献