Microwave (MW) rapid heating has received considerable attention as a new promising method for the one-pot synthesis of metallic nanostructures in solutions. In this concept, advantageous application been demonstrated by using some typical examples preparation Ag, Au, Pt, and AuPd nanostructures. Not only spherical nanoparticles, but also single crystalline polygonal plates, sheets, rods, wires, tubes, dendrites were prepared within few minutes under MW heating. Morphologies sizes could be...

Epitaxial chemical vapor deposition (CVD) growth of uniform single-layer graphene is demonstrated over Co film crystallized on c-plane sapphire. The single crystalline realized the sapphire substrate by optimized high-temperature sputtering and successive H2 annealing. This enables formation graphene, while a polycrystalline deposited SiO2/Si gives number flakes with various thicknesses. Moreover, an epitaxial relationship between as-grown lattice observed when synthesis occurs at 1000 °C;...

This perspective discusses recent advances in using strain to engineer the properties of thin-layer materials such as graphene and transition metal dichalcogenides (TMDs).

Size, orientation, and boundary of graphene domains are the current focus chemical vapor deposition (CVD) growth because they closely related to graphene's physical properties. Here, we study domain structure single-layer grown by ambient pressure CVD over heteroepitaxial Cu(111) Cu(100) films. Low energy electron microscope measurements reveal that film gives uniform whose orientation is consistent with underlying Cu lattice for areas 1 mm2. On other hand, on exhibits clear multidomain two...

Au@Ag core−shell nanocrystals have been synthesized by using a microwave−polyol method, and their growth mechanisms studied. When HAuCl4·4H2O was reduced in ethylene glycol the presence of poly(vinylpyrrolidone) (PVP) as polymer surfactant, mixture triangular twin platelike, octahedral, multiple-twinned decahedral Au nanocrystals, having only {111} facets, prepared. Ag+ these seeds, triangular-bipyramidal, cubic, rod/wire Ag shells, {100} were overgrown, respectively. It concluded that...

On single-crystal substrates, such as sapphire (alpha-Al 2O 3) and quartz (SiO 2), single-walled carbon nanotubes (SWNTs) align along specific crystallographic axes of the crystal, indicating that SWNT growth is influenced by crystal surface. Here, we show not only orientation, but also diameter chirality SWNTs are affected plane substrate. The aligned grown on A- R-planes have narrower distributions than randomly oriented tubes produced C-plane amorphous SiO 2. Photoluminescence...

Control over chemical reactivity is essential in the field of nanotechnology. Graphene a two-dimensional atomic sheet sp(2) hybridized carbon with exceptional properties that can be altered by functionalization. Here, we transferred single-layer graphene onto flexible substrate and investigated functionalization using different aryl diazonium molecules while applying mechanical strain. We found strain alter structure graphene, dramatically increase reaction rate, factor up to 10, as well...

For electronic applications, synthesis of large-area, single-layer graphene with high crystallinity is required. One the most promising and widely employed methods chemical vapor deposition (CVD) using Cu foil/film as catalyst. However, CVD generally polycrystalline contains a significant amount domain boundaries that limit intrinsic physical properties graphene. In this Perspective, we discuss growth mechanism on catalyst review recent development in observation control structure We...

Multilayered heterostructures of two-dimensional materials have recently attracted increased interest because their unique electronic and optical properties. Here, we present chemical vapor deposition (CVD) growth triangular crystals monolayer MoS2 on single-crystalline hexagonal graphene domains which are also grown by CVD. We found that grows selectively the rather than bare supporting SiO2 surface. Reflecting heteroepitaxy process, two preferred equivalent orientations. The interaction...

Rapid sphere-to-prism (STP) transformation of silver was studied in aqueous AgNO(3)/NaBH(4)/polyvinylpyrrolidone (PVP)/trisodium citrate (Na(3)CA)/H(2)O(2) solutions by monitoring time-dependent surface plasmon resonance (SPR) bands the UV-vis region, examining transmission electron microscopic (TEM) images, and analyzing emitted gases during fast reaction. Roles PVP, Na(3)CA, H(2)O(2) were without addition a reagent, with different timing each reagent's addition, to mixtures spheres prisms....

Band gap opening in bilayer graphene (BLG) under a vertical electric field is important for the realization of high performance graphene-based semiconductor devices, and thus, synthesis uniform large-area BLG required. Here we demonstrate highly film by chemical vapor deposition (CVD) over epitaxial Cu−Ni (111) binary alloy catalysts. The relative concentration Ni Cu as well growth temperature cooling profile was found to strongly influence uniformity BLG. In particular, slow process after...

We report ambient pressure chemical vapor deposition (CVD) growth of single-crystalline NbS2 nanosheets with controlled orientation. On Si and SiO2 substrates, grow almost perpendicular to the substrate surface. However, when we apply transferred CVD graphene on as a substrate, sheets laterally lying graphene. The show triangular hexagonal shapes thickness about 20–200 nm several micrometres in lateral dimension. Analyses based X-ray diffraction Raman spectroscopy indicate that are single...

PtRu alloy nanoparticles (24 ± 1 wt %, Ru/Pt atomic ratios = 0.91−0.97) supported on carbon nanofibers (CNFs) were prepared within a few minutes by using microwave-polyol method. Three types of CNFs with very different surface structures, such as platelet, herringbone, and tubular ones, used new supports. The dependence particles sizes electrochemical properties the structures was examined. It found that methanol fuel cell activities PtRu/CNF catalysts in order platelet > herringbone....

Single-walled carbon nanotubes (SWNTs) with a narrow diameter distribution are synthesized by thermal chemical vapor deposition (CVD) of methane over Fe/MgO catalyst on the basis parametric study considering Fe loading, reaction temperature and time, concentration, structure support material. We found that porous MgO gives SWNTs mean standard deviation 0.93 0.06 nm, respectively, only when loading relatively low. The higher and/or enlarged nanotube diameter, forming double-walled (DWNTs) in...

Shape-dependent Au@Ag core−shell nanocrystals have been successfully synthesized by using a two-step method. First, Au nanocrystal seeds with various shapes including single-crystal octahedron, single-twinned triangle or hexagon plate, and multiple-twinned decahedron were prepared reducing HAuCl4 in ethylene glycol (EG) the presence of polyvinylpyrrolidone (PVP) as polymer surfactant under condition microwave heating. Subsequently, thus-obtained added into N,N-dimethylformamide (DMF)...

The catalytic growth of single- and double-walled carbon nanotubes (SWNTs DWNTs) by chemical vapor deposition (CVD) strongly depends on the support material. Not only presence nanopores in material but also interaction with metal particles is believed to play an important role. Here, we study roles metal−support employing iron a mean diameter 9.8 nm supported crystalline magnesia (MgO) powder. MgO powder has flat surface few so that change particle size can be observed transmission electron...