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1.
Y.F. Zhu G.H. Zhou H.Y. Ding A.H. Liu Y.B. Lin Y.W. Dong 《Superlattices and Microstructures》2011,50(5):549-556
The strategy to manipulate nanoscale building blocks into well-organized heterostructures is very important to both material synthesis and nanodevice applications. In this work, highly-ordered ZnO/PbS core/shell nanowire arrays were fabricated by a facile and low temperature chemical route. Large area and well-aligned ZnO nanowire arrays were firstly fabricated on conductive glass substrates, and then the synthesis of ZnO/ZnS and ZnO/PbS core/shell nanowire arrays were realized by a chemical conversion method. The morphology, structure, and composition of the obtained nanostructures were confirmed by field-emission scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction measurements. The optical properties of the synthesized nanostructures were investigated by micro-Raman and photoluminescence spectroscopy. In the synthesized ZnO/PbS core/shell nanowire arrays, the ZnO cores can provide direct conduction pathways for electron transport and PbS shells possess superior photoelectric performance. Therefore, the obtained ZnO/PbS core/shell nanostructures may have potential application in photovoltaic devices. 相似文献
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S. V. Antonenko O. S. Malinovskaya S. N. Mal’tsev 《Journal of Experimental and Theoretical Physics》2007,105(1):201-202
The multiwalled carbon nanotube films examined in this study are produced by two methods: current annealing of carbon paper and dc magnetron sputtering. The conductivity and the temperature dependence of resistance of the samples are measured. The thermal conductivity of the film-substrate system is evaluated. 相似文献
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I. Echeverría A. Urbina 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(3):491-496
We have prepared solutions of multiwalled carbon nanotubes in very low
vapour pressure solvents (a mixture of chlorinated biphenyls). The solutions
are stable and show no sign of precipitation for six months. Rheological
measurements using a modified Birnboim apparatus with annular and Sogel-Pochetino geometries have been performed.
Using time-temperature superposition we obtained the real and imaginary part of the complex viscosity coefficient in
a frequency range covering eight orders of magnitude and a temperature range
from 5 to 50 ○C. The data shows unexpected changes in the solution with
temperature: for T below 30 ○C there appears to be some
reorganization or clustering. This self-organization could result in
a useful technique to improve the electronic properties of polymer/carbon
nanotubes composites used in organic electronic devices. 相似文献
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基于CdS良好的光学性质和单壁碳纳米管(SWCNT)优异的电子学性质, 制备了纳米CdS/SWCNT复合材料和纳米CdS/聚乙烯亚胺(PEI)功能化SWCNT复合材料, 并利用日光灯光源模拟太阳光研究了它们的光电性质. 结果表明, 纳米CdS/SWCNT复合材料呈现显著的负光电导现象, 而纳米CdS/PEI-SWCNT复合材料呈现强烈的正光电导现象. 用电子转移理论对这一结果进行了解释. 两样品在大角度弯折的情况下, 光电性质均基本没有变化. 因此, 纳米CdS/碳纳米管复合材料在光电领域, 尤其是新兴的柔性光电子学领域有着良好的应用前景.
关键词:
碳纳米管
CdS
光电材料
复合材料 相似文献
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Thermotropic liquid crystalline polyester (TLCP) was synthesized via low-temperature solution polycondensation from 1,4-Bis(4-Hydroxybenzoyloxy)butane and terephthaloyl dichloride. Polymer nanocomposites based on a small quantity of multi-walled carbon nanotubes (MWNTs) were prepared by in situ polymerization method. The wide-angle X-ray diffraction (WAXD) results suggested that the addition of MWNTs to TLCP matrix did not significantly change the crystal structure of TLCP. The interactions between the molecules of the TLCP host phase and the carbon nanotubes were investigated through Raman spectroscopy investigations. We detected a distinct wave number shift of the radial breathing modes, confirming the carbon nanotubes interacted with the surrounding liquid crystal molecules, most likely through aromatic interactions (π-stacking). The interactions between liquid crystal host and nanotube guests were also evident from a polarizing microscopy (POM) study of the liquid crystal-isotropic phase transition in the proximity of nanotubes. The thermal properties and the morphological properties of the TLCP/MWNTs nanocomposites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). TGA data demonstrated the addition of a small amount of MWNTs into TLCP matrix could improve the thermal stability of TLCP matrix. DSC results revealed that melt transition temperatures and isotropic transition temperatures of the hybrids were enhanced. 相似文献
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An attempt has been made to prepare and characterise ammonium thiocyanate (NH4SCN) salt and a multiwall carbon nanotube (MWNT)-doped polyvinyl alcohol-based nanofibre mats using an electrospinning process. The X-ray diffraction result shows an improvement in the amorphous nature of composite electrolyte fibre mats with increasing concentrations of the MWNT filler. The DSC behaviour of these nanofibre mat exhibits better thermal response upon dispersal of the filler. Composite electrolyte nanofibre mat doped with 6 wt% MWNT shows optimum conductivity, viz., 5.8?×?10?4 Scm?1. The temperature dependence of the bulk electrical conductivity displays a combination of Arrhenius and Vogel–Tammam–Fulcher nature. Dielectric loss studies have also been used to understand the conduction process in the system. Jonscher power law seems to be obeyed during ac conductivity measurements of the fibre mats. 相似文献
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We have investigated electrical transport in a diffusive multiwalled carbon nanotube contacted using superconducting leads made of an Al/Ti sandwich structure. We find proximity-induced superconductivity with measured critical currents up to I(cm)=1.3 nA, tunable by the gate voltage down to 10 pA. The supercurrent branch displays a finite zero bias resistance which varies as R(0) proportional to I(cm){-alpha} with alpha=0.74. Using IV characteristics of junctions with phase diffusion, a good agreement is obtained with the Josephson coupling energy in the long, diffusive junction model of A. D. Zaikin and G. F. Zharkov [Sov. J. Low Temp. Phys. 7, 184 (1981)]. 相似文献
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Thorn-like, organometallic-functionalized carbon nanotubes were successfully developed via a novel microwave hydrothermal route. The organometallic complex with methyl orange and iron (III) chloride served as reactive seed template, resulting in the oriented polymerization of pyrrole on the modified carbon nanotubes without the assistance of other oxidants. Morphological and structural characterizations of the carbon nanotube/methyl orange-iron (III) chloride and polypyrrole/carbon nanotube composites were examined using transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), infrared spectroscopy and X-ray diffraction (XRD). The electrochemical property of the polypyrrole/carbon nanotube composite was elucidated by cyclic voltammetry and galvanostatic charge-discharge. A specific capacitance of 304 F g−1 was obtained within the potential range of −0.5-0.5 V in 1 M KCl solution. 相似文献
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Suchita Kalele Ravi Dey Neha Hebalkar J. Urban S. W. Gosavi S. K. Kulkarni 《Pramana》2005,65(5):787-791
Abstract Nearly monodispersed particles of silica were prepared and coated with uniform layers of titanium dioxide in anatase phase
by hydrolysis and condensation of titanium butoxide. The coating thickness could be altered by adjusting the concentration
of reactants (titanium butoxide and water) and the amount of added silica particles. Different coating thicknesses were deposited
and studied using optical absorption spectroscopy, electron microscopy and Fourier transform infra-red spectroscopy. It was
found that silica particles of size 170 ±5 nm were coated with 23±5 nm thick layer of titanium dioxide. Alternatively titania
particles of size 340±5 nm were synthesized by controlled hydrolysis of titanium ethoxide in the presence of sodium chloride.
These particles were further coated with 135±5 nm thick layer of silica to investigate changes in properties after changing
the shell material 相似文献
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Jesionek M Nowak M Szperlich P Stróż D Szala J Jesionek K Rzychoń T 《Ultrasonics sonochemistry》2012,19(1):179-185
This paper presents, for the first time, the nanocrystalline, semiconducting antimony selenoiodide (SbSeI) grown in multi-walled carbon nanotubes (CNTs). It was prepared sonochemically using elemental Sb, Se, and I in the presence of ethanol under ultrasonic irradiation (35 kHz, 2.6 W/cm2) at 323 K for 3 h. The CNTs filled with SbSeI were characterized by using techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, and optical diffuse reflection spectroscopy. These investigations exhibit that the SbSeI filling the CNTs is single crystalline in nature and in the form of nanowires. It has indirect allowed energy band gap EgIf = 1.61(6) eV. 相似文献
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M. Nowak M. Jesionek P. Szperlich J. Szala T. Rzycho D. Str 《Ultrasonics sonochemistry》2009,16(6):800-804
This paper presents for the first time the nanocrystalline, semiconducting ferroelectrics antimony sulfoiodide (SbSI) grown in multiwalled carbon nanotubes (CNTs). It was prepared sonochemically using elemental Sb, S and I in the presence of methanol under ultrasonic irradiation (35 kHz, 2.6 W/cm2) at 323 K for 3 h. The CNTs filled with SbSI were characterized by using techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, and optical diffuse reflection spectroscopy. These investigations exhibit that the SbSI filling the CNTs is single crystalline in nature and in the form of nanowires. It has indirect forbidden energy band gap EgIf = 1.871(1) eV. 相似文献
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Atomic force microscopy (AFM) was employed for the morphology measurements of bamboo-shaped multiwalled carbon nanotubes (BS-MWNTs) grown by thermal chemical vapor deposition on Fe catalyst deposited SiO2/Ti substrates. Greater diameters and compartment distances of the bamboo structures were observed for the BS-MWNTs grown at 950 °C than for those grown at 850 °C. 相似文献
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Preparation of water-soluble CdTe/CdS core/shell quantum dots with enhanced photostability 总被引:1,自引:0,他引:1
Hui Peng 《Journal of luminescence》2007,127(2):721-726
CdTe/CdS core/shell quantum dots (QDs) have been synthesized in an aqueous phase using thioacetamide as a sulfur source. The quantum yield was greatly enhanced by the epitaxial growth of a CdS shell, which was confirmed by X-ray photoelectron spectroscopy (XPS) results. The quantum yield of as-prepared CdTe/CdS core/shell QDs without any post-preparative processing reached 58%. The experimental results illustrate that the QDs with core/shell structure show better photostability than thioglycolic acid (TGA)-capped CdTe QDs. The cyclic voltammograms reveal higher oxidation potentials for CdTe/CdS core/shell QDs than for TGA-capped CdTe QDs, which explains the superior photostability of QDs with a core/shell structure. This enhanced photostability makes these QDs with core/shell structure more suitable for bio-labeling and imaging. 相似文献
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Bailing Liu Xiaobo Deng Shunsheng Cao Songjun Li Rong Luo 《Applied Surface Science》2006,252(6):2235-2241
The core/shell particles consisting of polystyrene core and 3-(methacryloxypropyl)-trimethoxysilane (MPS) shell were prepared in the present study by successive seeding polymerization under kinetically controlled conditions and were characterized by particle size analyser, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The TEM image indicated that the particles containing organic siloxane presented an evident core/shell structure. Additionally, the study of XPS also revealed that MPS could be grafted onto the surface of polystyrene microspheres and the atomic ratio of C/Si on the surface of the core/shell particles (MPS-40) was very close to the ratio of C/Si in the molecule of MPS. The surface properties of the films produced from the core/shell particles were also investigated by the static contact angle method. Compared with the homopolymer of PS, the core/shell particles were more effective to create hydrophobic surface, so, the introduction of MPS was capable of obvious increase in water repellency. 相似文献
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用Pt细丝代替已有3ω方法中的薄膜热线,并设计了基于Labview程序的虚拟测量系统,准确、方便地测量了聚丙烯复合材料的热导率. 测量结果发现,多壁碳纳米管/丁苯橡胶/聚丙烯三元复合材料的热导率随着多壁碳纳米管/丁苯橡胶粉末含量的增加变化不大;多壁碳纳米管/聚丙烯复合材料的热导率随着多壁碳纳米管含量增加而增大;复合材料热导率远小于简单混合规则预测的结果,而与有效介质理论符合很好.
关键词:
ω法')" href="#">3ω法
多壁碳纳米管
聚丙烯复合材料
热导率 相似文献
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The authors have successfully synthesized Pd-on-Pt (thickness: 12 nm) and Au-on-Pt bimetallic nanosheaths on multiwalled carbon
nanotubes (MWCNTs) via a seed-mediated growth approach. Pt nanoparticles as seeds were pre-deposited on MWCNTs with uniform
distribution followed by the successive seed-mediated growth of metal atoms reduced by a weak reducing agent, ascorbic acid.
The essential role of pre-deposited nanoseed particles on MWCNTs was demonstrated. The as-prepared materials were characterization
by transition electron microscopy, energy-dispersive X-ray spectroscopy, and element mapping tools. The current strategy extends
the classical seed-mediated growth method to prepare bimetallic nanosheath on MWCNT support. 相似文献