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1.
An essay on synthetic chemistry of colloidal nanocrystals 总被引:1,自引:0,他引:1
Xiaogang Peng 《Nano Research》2009,2(6):425-447
The central goal of synthetic chemistry of colloidal nanocrystals at present is to discover functional materials. Such functional
materials should help mankind to meet the tough challenges brought by the rapid depletion of natural resources and the significant
increase of population with higher and higher living standards. With this thought in mind, this essay discusses the basic
guidelines for developing this new branch of synthetic chemistry, including rational synthetic strategies, functional performance,
and green chemistry principles.
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2.
We demonstrate the role of catalysts in the surface growth of single-walled carbon nanotubes (SWNTs) by reviewing recent progress
in the surface synthesis of SWNTs. Three effects of catalysts on surface synthesis are studied: type of catalyst, the relationship
between the size of catalyst particles and carbon feeding rates, and interactions between catalysts and substrates. Understanding
of the role of catalysts will contribute to our ability to control the synthesis of SWNTs on various substrates and facilitate
the fabrication of nanotube-based devices.
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3.
Dingsheng Wang Xiaoling Ma Yanggang Wang Li Wang Zhongying Wang Wen Zheng Xiangming He Jun Li Qing Peng Yadong Li 《Nano Research》2010,3(1):1-7
Shape control of nanocrystals has become a significant subject in materials science. In this work, we describe a convenient
way to achieve morphology-controllable synthesis of CoO nanocrystals including octahedrons and spheres as well as LiCoO2 polyhedrons and spheres. In particular, we explain the formation of CoO octahedrons exposing only high-energy (111) facets
using theoretical calculations; these should also be a useful tool for directing future face-controlled preparation of other
nanocrystals. More importantly, the as-obtained LiCoO2 nanocrystals showed different electrochemical performance depending on their morphology, indicating that Li-insertion/deintercalation
dynamics might be crystal face-sensitive.
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4.
The purpose of this review is to highlight developments in self-assembled nanostructured materials (i.e., mesoporous and nanoparticle-based
materials) and their catalytic applications. Since there are many available reviews of metal-based nanoparticles as catalysts,
this review will mainly focus on self-assembled oxide-based catalytic materials. The content includes: (1) design and synthetic
strategies for self-assembled mesoporous catalysts, (2) polyoxometalate (POM)-based nanocatalysts, (3) dendrimer-based nanocatalysts,
and (4) shaped nanomaterials and catalytic applications. We show that controlled assembly of molecules, crystalline seeds,
and nano building blocks into organized mesoscopic structures or controlled morphologies is an effective approach for tailoring
porosities of heterogeneous catalysts and controlling their catalytic activities.
This article is published with open access at Springerlink.com 相似文献
5.
Metallic nanostructures with hollow interiors or tailored porosity represent a special class of attractive materials with
intriguing chemicophysical properties. This paper presents the fabrication of a new type of metallic nanoporous nanotube structure
based on a facile and effective combination of nanocrystal growth and surface modification. By controlling the individual
steps involved in this process, such as nanowire growth, surface modification, thermal diffusion, and dealloying, one-dimensional
(1-D) metallic nanostructures can be prepared with tailored structural features and pre-designed functionalities. These tubular
and porous nanostructures show distinct optical properties, such as tunable absorption in the near-infrared region, and enhanced
capability for electrochemiluminescence signal amplification, which make them particularly desirable as novel 1-D nanocarriers
for biomedical, drug delivery and sensing applications.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
6.
Two simple methods have been demonstrated to obtain large area, single crystalline lamellae of copper-7,7,8,8-tetracyanoquinodimethane
(CuTCNQ). The formation of the lamellae was a result of fine tuning of the processes during the synthesis processes of CuTCNQ
phase II. This facile synthesis of large area single crystalline lamellae suggests bright prospects for the study and understanding
of the electrical switching of CuTCNQ by using single crystals of its phase II, and future applications of the material in
memory and switching devices.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
7.
We report synthesis windows for growth of millimeter-long ZnTe nanoribbons and ZnSe nanowires using vapor transport. By tuning
the local conditions at the growth substrate, high aspect ratio nanostructures can be synthesized. A Cu-ion immersion doping
method was applied, producing strongly p-type conduction in ZnTe and ionic conduction in ZnSe. These extreme aspect ratio
wide-bandgap semiconductors have great potential for high density nanostructured optoelectronic circuits.
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8.
Hongwang Zhang Savas Delikanli Yueling Qin Shuli He Mark Swihart Hao Zeng 《Nano Research》2008,1(4):314-320
Semiconductor nanocrystals (dots, rods, wires, etc.) exhibit a wide range of electrical and optical properties that differ
from those of the corresponding bulk materials. These properties depend on both nanocrystal size and shape. Compared with
nanodots, nanorods have an additional degree of freedom, the length or aspect ratio, and reduced symmetry, which leads to
anisotropic properties. In this paper, we report the Au nanoparticlecatalyzed colloidal synthesis of monodisperse CdS nanorods.
Based on systematic high resolution transmission electron microscopy studies, we propose a growth mechanism for these nanorods.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.
This article is published with open access at Springerlink.com 相似文献
9.
Nanocrystalline intermetallics and alloys are novel materials with high surface areas which are potential low-cost and high-performance
catalysts. Here, we report a general approach to the synthesis of a large variety of nanocrystalline intermetallics and alloys
with controllable composition, size, and morphology: these include Au-, Pd-, Pt-, Ir-, Ru-, and Rh-based bi- or tri-metallic
nanocrystals. We find that only those intermetallics and alloys whose effective electronegativity is larger than a critical
value (1.93) can be prepared by co-reduction in our synthetic system. Our methodology provides a simple and convenient route
to a variety of intermetallic and alloyed nanomaterials which are promising candidates for catalysts for reactions such as
methanol oxidation, hydroformylation, the Suzuki reaction, cyclohexene hydroconversion, and the selective hydrogenation of
acetylene.
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10.
Owing to their structural dispersion, the catalytic properties of nanoparticles are challenging to characterize in ensemble-averaged
measurements. The single-molecule approach enables studying the catalysis of nanoparticles at the single-particle level with
real-time single-turnover resolution. This article reviews our single-molecule fl uorescence studies of single Au-nanoparticle
catalysis, focusing on the theoretical formulations for extracting quantitative reaction kinetics from the single-turnover
resolution catalysis trajectories. We discuss the single-molecule kinetic formulism of the Langmuir-Hinshelwood mechanism
for heterogeneous catalysis, as well as of the two-pathway model for product dissociation reactions. This formulism enables
the quantitative evaluation of the heterogeneous reactivity and the differential selectivity of individual nanoparticles that
are usually hidden in ensemble measurements. Extension of this formulism to single-molecule catalytic kinetics of oligomeric
enzymes is also discussed.
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11.
Keun Su Kim Ala Moradian Javad Mostaghimi Yasaman Alinejad Ali Shahverdi Benoit Simard Gervais Soucy 《Nano Research》2009,2(10):800-817
The production of high quality single-walled carbon nanotubes (SWCNTs) on a bulk scale has been an issue of considerable interest.
Recently, it has been demonstrated that high quality SWCNTs can be continuously synthesized on large scale by using induction
thermal plasma technology. In this process, the high energy density of the thermal plasma is employed to generate dense vapor-phase
precursors for the synthesis of SWCNTs. With the current reactor system, a carbon soot product which contains approximately
40 wt% of SWCNTs can be continuously synthesized at the high production rate of ∼100 g/h. In this article, our recent research
efforts to achieve major advances in this technology are presented. Firstly, the processing parameters involved are examined
systematically in order to evaluate their individual influences on the SWCNT synthesis. Based on these results, the appropriate
operating conditions of the induction thermal plasma process for an effective synthesis of SWCNTs are discussed. A characterization
study has also been performed on the SWCNTs produced under the optimum processing conditions. Finally, a mathematical model
of the process currently under development is described. The model will help us to better understand the synthesis of SWCNTs
in the induction plasma process.
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12.
Xiaobing Han Guangyin Jing Xinzheng Zhang Renmin Ma Xuefeng Song Jun Xu Zhimin Liao Ning Wang Dapeng Yu 《Nano Research》2009,2(7):553-557
Reliable ohmic contacts were established in order to study the strain sensitivity of nanowires and nanobelts. Significant
conductance increases of up to 113% were observed on bending individual ZnO nanowires or CdS nanobelts. This bending strain-induced
conductance enhancement was confirmed by a variety of bending measurements, such as using different manipulating tips (silicon,
glass or tungsten) to bend the nanowires or nanobelts, and is explained by bending-induced effective tensile strain based
on the principle of the piezoresistance effect.
This article is published with open access at Springerlink.com 相似文献
13.
Synthesis of high magnetic moment CoFe nanoparticles via interfacial diffusion in core/shell structured Co/Fe nanoparticles 总被引:1,自引:0,他引:1
We report the synthesis of high magnetic moment CoFe nanoparticles via the diffusion of Co and Fe in core/shell structured
Co/Fe nanoparticles. In an organic solution, Co nanoparticles were coated with a layer of Fe to form a Co/Fe core/shell structure.
Further raising the solution temperature led to inter-diffusion of Co and Fe and formation of CoFe alloy nanoparticles. These
nanoparticles have high saturation magnetization of up to 192 emu/g CoFe and can be further stabilized by thermal annealing
at 600 °C.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.
These two authors made an equal contribution to the work. 相似文献
14.
Wei Xu Mingdong Dong Henkjan Gersen Socorro Vázquez-Campos Xavier Bouju Erik Lægsgaard Ivan Stensgaard Mercedes Crego-Calama David N. Reinhoudt Trolle R. Linderoth Flemming Besenbacher 《Nano Research》2009,2(7):535-542
We present an interplay of high-resolution scanning tunneling microscopy imaging and the corresponding theoretical calculations
based on elastic scattering quantum chemistry techniques of the adsorption of a gold-functionalized rosette assembly and its
building blocks on a Au(111) surface with the goal of exploring how to fabricate functional 3-D molecular nanostructures on
surfaces. The supramolecular rosette assembly stabilized by multiple hydrogen bonds has been sublimed onto the Au(111) surface
under ultra-high vacuum conditions; the resulting surface nanostructures are distinctly different from those formed by the
individual molecular building blocks of the rosette assembly, suggesting that the assembly itself can be transferred intact
to the surface by in situ thermal sublimation. This unanticipated result will open up new perspectives for growth of complex 3-D supramolecular nanostructures
at the vacuum-solid interface.
This article is published with open access at Springerlink.com 相似文献
15.
16.
Wenjie Liang Oded Rabin Allon I. Hochbaum Melissa Fardy Minjuan Zhang Peidong Yang 《Nano Research》2009,2(5):394-399
The thermoelectric properties of individual solution-phase synthesized p-type PbSe nanowires have been examined. The nanowires
showed near degenerately doped charge carrier concentrations. Compared to the bulk, the PbSe nanowires exhibited a similar
Seebeck coefficient and a significant reduction in thermal conductivity in the temperature range 20 K to 300 K. Thermal annealing
of the PbSe nanowires allowed their thermoelectric properties to be controllably tuned by increasing their carrier concentration
or hole mobility. After optimal annealing, single PbSe nanowires exhibited a thermoelectric figure of merit (ZT) of 0.12 at
room temperature.
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17.
Supramolecular proteins are generated using a limited set of twenty amino acids, but have distinctive functionalities which
arise from the sequential arrangement of amino acids configured to exquisite three-dimensional structures. Viruses, virus-like
particles, ferritins, enzyme complexes, cellular micro-compartments, and other supramolecular protein assemblies exemplify
these systems, with their precise arrangements of tens to hundreds of molecules into highly organized scaffolds for nucleic
acid packaging, metal storage, catalysis or sequestering reactions at the nanometer scale. These versatile protein systems,
dubbed as bionanoparticles (BNPs), have attracted materials scientists to seek new opportunities with these pre-fabricated
templates in a wide range of nanotechnology-related applications. Here, we focus on some of the key modification strategies
that have been utilized, ranging from basic protein conjugation techniques to more novel strategies, to expand the functionalities
of these multimeric protein assemblies. Ultimately, in combination with molecular cloning and sophisticated chemistries, these
BNPs are being incorporated into many applications ranging from functional materials to novel biomedical drug designs.
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18.
Facile dry decoration of graphene oxide sheets with aerosol Ag nanocrystals synthesized from an arc plasma source has been
demonstrated using an electrostatic force directed assembly technique at room temperature. The Ag nanocrystal-graphene oxide
hybrid structure was characterized by transmission electron microscopy (TEM) and selected area diffraction. The ripening of
Ag nanocrystals on a graphene oxide sheet was studied by consecutive TEM imaging of the same region on a sample after heating
in Ar at elevated temperatures of 100 °C, 200 °C, and 300 °C. The average size of Ag nanocrystals increased and the number
density decreased after the annealing process. In particular, migration and coalescence of Ag nanocrystals were observed at
a temperature as low as 100 °C, suggesting a van der Waals interaction between the Ag nanocrystal and the graphene oxide sheet.
The availability of affordable graphene-nanocrystal structures and their fundamental properties will open up new opportunities
for nanoscience and nanotechnology and accelerate their applications.
This article is published with open access at Springerlink.com 相似文献
19.
A facile strategy using cheap and readily available precursors has been successfully developed for the synthesis of rare-earth
doped hexagonal phase NaYF4 nanocrystals with uniform shape and small particle size as well as strong photoluminescence. Due to their optical properties
and good biocompatibility, these multicolor nanocrystals were successfully used as a bio-tag for cancer cell imaging. This
novel synthetic method should also be capable of extension to the synthesis of other fluoride nanocrystals such as YF3 and LaF3.
相似文献
20.
Ernesto Joselevich 《Nano Research》2009,2(10):743-754
The organization of carbon nanotubes into well-defined straight or curved geometries and arrays on surfaces is a critical
prerequisite for their integration into nanocircuits and a variety of functional nanosystems. We review the recent development
of a new approach to carbon nanotube organization based on self-organized growth directed by well-defined crystal surfaces,
or “nanotube epitaxy”. We identify three different modes of surface-directed growth, namely by atomic rows, atomic steps,
and nanofacets. Particular emphasis is given here to the combinations of such surface-directed growth with external forces—like
those exerted by an electric field or gas flow—for the creation of well-defined complex geometries, including crossbar architectures,
serpentines, and coils.
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