Great efforts have been made toward the syntheses of nanocomposites of inorganic materials and carbon nanotubes (CNTs), [1][2][3][4][5] with the aim of exploiting the unique properties of CNTs (such as a high aspect ratio, low mass, flexibility, a high mechanical strength, and high electrical and thermal conductivities) for applications in heterogeneous catalysis, [2] fuel cells, [3] supercapacitors, [4] lithium-ion batteries (LIBs), [5] and optoelectronic devices.[6] The performances of these nanocomposites should be significantly affected by at least one of three key structural factors: uniformity, maintenance of the electrical contacts between CNTs, and porosity. Therefore, it is of fundamental interest to develop synthetic strategies for uniformly loading inorganic materials onto the surfaces of CNTs and CNT bundles within mesoporous sheets without disturbing the electrical contacts between the CNTs, so that such materials can be used in fuel cells, supercapacitors, and LIBs. To the best of our knowledge, the only previous attempt (in which layers of V 2 O 5 ÁxH 2 O with a 6 nm thickness were electrochemically loaded onto CNT films) had not been fully successful; aggregates were clearly observed on the surface of the films.[4b]Here, we report the uniform loading of SnO 2 nanoparticles (NPs) onto a CNT network composed of 1 Â 1 cross-stacked sheets (see Scheme S1, Supporting Information); the NPs are observed on the surface of each multiwalled CNT and of each CNT bundle within the network. This technique may be useful in the fabrication of high-capacity anodes for rechargeable LIBs. Additional considerations for the design of the novel composite arise because all three key factors are very important to this application.Tin-based materials have also attracted great attention as potential substitutes for current carbonaceous materials because of their higher specific capacities (981 mA h g À1 for Sn, 1491 mA h g À1 for SnO 2 , assuming that all Sn was oxidized to Sn 4þ , approximately 360 mA h g À1 for C-based materials). [7][8][9] However, anodes of such high capacity usually suffer severe capacity fading stemming from both the quick aggregation of tin particles and the huge volume change (over 300%) during Li þ insertion/extraction cycles, which causes pulverization of the anodes and electrical detachment of active materials. [9] Reducing the materials' size down to the nanoscale and dispersing the materials into mesoporous structures have proved very effective in solving the problems of similar systems.[5b,10] There have already been some reports of applying inorganic-CNT composites to high-capacity anodes for LIBs, [5b-d] but all of these composites were prepared using CNTs as collectors for sediments, so carbon black and polymer binders had to be used to lower the resistance and hold the electrodes together. In contrast, CNT sheets have been demonstrated to be very attractive candidates for freestanding (no need for copper foil substrates as current collectors) and binder-free anodes (no need for po...

1-Nonanethiol-capped silver nanoparticles of about 4.18 nm in diameter were prepared using a liquid−liquid two-phase method. Two-dimensional ordered superlattices of the nanoparticles were formed on carbon films coated on transmission electron microscopy (TEM) copper grids by evaporating a drop of the dispersion in chloroform. The formation process of the silver nanoparticles was investigated by UV−visible absorption spectroscopy and TEM. A blue shift of the maximum absorption peak position of the UV−vis spectra occurred at the beginning of the reaction, followed by a red shift. This result indicated that large thiol-capped silver nanoparticles were formed at the beginning, then the large particles were decomposed into small particles, and in the final stage the small particles enlarged slightly again. The TEM images show directly the same process with the results from the UV−vis spectra. In addition, the UV−visible spectra of the silver nanoparticle colloidal phase obtained finally show that the system is monodisperse and can remain stable for several weeks.

Three-dimensional, orthogonal lead sulfide (PbS) nanowire arrays and networks have been prepared by using a simple, atmospheric pressure chemical vapor deposition (APCVD) method. These uniform nanowires (average diameter 30 nm) grow epitaxially from the surface of the initial PbS crystal seeds and form orthogonal arrays and networks in space. The growth mechanism has been explored, and the process was classified as homogeneous, epitaxial growth in the 200 directions. Furthermore, Raman spectra of PbS nanowires are reported here, and their characteristic Raman peak (190 cm(-1), no shoulder) could be used as a unique probe for the study of PbS nanomaterials.

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ZnS:M2+ (M = Mn, Co, or Cu) single‐crystal one‐dimensional nanostructures have been prepared via a simple halide‐transport chemical vapor deposition (HTCVD) process at a relatively low temperature. The obvious phase transition suggests that doping with Mn favors the formation of the hexagonal phase at a relative low temperature. The strong photoluminescence from blue to green and the yellow–orange emission, which was caused by the doping of various elements in ZnS nanowires and nanobelts, suggests possible applications of the one‐dimensional nanostructures in nanoscale optoelectronic devices.

A series of transition-metal sulfide one-dimensional (1D) nanostructures have been synthesized by means of a general atmospheric pressure, chemical vapor deposition (APCVD) strategy. Vapour-liquid-solid (VLS) and vapour-solid (VS) mechanisms, along with the results of SEM and TEM observations, were used to explain the formation of these nanostructures. The regularity of the growth in the direction of the hexagonal nanowire is explored; we find that it prefers to grow along (1 0 0), (1 1 0), or (0 0 x) directions owing to particular crystal structures. The adopted synthetic route was expected to provide abundant useful 1D building blocks for the research of mesoscopic physics and fabrication of nanoscale devices.

We have studied the growth of silica-sheathed 3C-Fe7S8 products on silicon substrates with FeCl2 and sulfur precursors at the temperature region of 600-800 degrees C. On the basis of the crystal structure of Fe7S8, we have proposed a model including the kinetic competition of the adsorption of silica species on Fe2-Fe3-Fe4 units at the 4Fe layer and on the Fe2-Fe3-Fe4-Fe5 units parallel to the c-axis. Using this model, we have not only explained all the experimental phenomena but also especially prepared Fe7S8 nanowires at 650 degrees C by introducing water into the reaction system.

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