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Although boron doped multi‐walled nanotubes have been synthesized by chemical vapor deposition (CVD) methods, the synthesis of single‐walled species was achieved only recently. In comparison to their carbon counterparts synthesized by similar methods, these nanotubes grow in relatively low amounts due to several experimental difficulties. On the other hand, the use of iron containing catalysts supported in porous materials is one of the most efficient ways to produce single walled pristine carbon nanotubes and several methods have been proposed to enhance this growth. In this contribution we have studied the possibilities to enhance the growth of boron doped single‐walled nanotubes using a triisopropyl borate non‐diluted precursor in a high‐vacuum CVD system. The catalyst composition and pretreatment, as well as the precursor‐feed have been studied in detail. An additional study of the Raman response our material has been made in order to prove the implicit changes with electrons and phonons upon doping.

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In this work, nickel oxide (NiO) films have been prepared by a sparking method on a flexible chromium/gold coated polyethylene terephthalate substrates and investigated for electrochemical energystorage applications. Structural characterizations by scanning/transmission electron microscopies, X-ray 10 diffraction, X-ray photoelectron spectroscopy and UV-vis spectrophotometer reveal that the film comprises polycrstalline NiO nanoparticles with diameters in the range of 3.0-6.0 nm loosely agglomerated into porous foam-like network. The nanoporous sparked NiO films, exhibits remarkable energy-storage behavior with a high average specific charge capacity of 402.75 C g -1 at a discharge current of 1 A g -1 and a good capacity retention of 88% after 1000 cycles at a high discharge current of 40 15 A g -1 . Thus, the sparking method is a promising alternative route for the preparation of high-performance electrochemical energy-storage devices. 65 storage performances are investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements. Materials and methodsThe schematic illustration of the sparking apparatus for the fabrication of NiO nanoparticles (NiO-NPs) and NiO films is 70

Iron oxide nanowires were synthesized on stainless steel mesh substrate using the thermal oxidation process at the varying temperature of 750°C for 60 min. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD pattern showed that the iron oxide nanowires exhibited the structure of alpha-Fe2O3 (hematite). SEM images indicated that the diameter and the length of the nanowires were 80 to 285 nm and more than 5 μm, respectively. The dye-sensitized solar cell (DSC) properties based on the nanowires substrate was also studied. It was found that the power conversion efficiency (η) of the device was 0.11%.

A controlled method for the production of tungsten oxide nanobelts through metal oxidation in presence of ethanol is proposed. At the optimal synthesis conditions, up to 20 μm long vertically aligned ribbon-like structures with a narrow rectangular cross section can be obtained in a tuned manner with preferential formation of WO2 in the presence of graphitic like carbon. Bulk and local-scale studies suggest that carbon diffusion to the surface of the material leads to the formation of mainly WO3 nanobelts from simple annealing treatments at 450 °C. This represents one alternative method to the common tungsten oxidation in air, opening the possibility to use C-containing compounds with negligible formation of carbide traces. An in-depth characterization of these materials has been performed, and the possible growth mechanisms are here discussed.

Single-walled carbon nanotubes (SWNTs) were grown on gold nanoparticle (GNP) coated quartz substrates by alcohol catalytic chemical vapor deposition. The GNP coated substrates were coated with Co catalyst by a dip-coat method. The growth was then carried out at 800 °C under a pressure of 10 Torr in an atmosphere of ethanol vapor for 30 min. Characterizations have shown larger SWNT diameters with higher negative temperature coefficients for GNP coated substrates as compared to those of quartz substrates without GNPs. It is attributed that SWNT-GNP hybrid structures have a higher fraction of semiconductor-type pathways.

In this paper, we report on the diameter distribution of borondoped single-walled carbon nanotubes grown from triethyl borate with high vacuum chemical vapor deposition, using multi-frequency Raman resonance spectroscopy. The nanotube yield is higher than in previously reported material produced with the same method. Our results suggest that the amount of as-grown material and the range of diameters are directly correlated with feedstock used in the synthesis. The I D /I G ratio shows that the morphology of the samples is critically affected by the temperature. The population of diameters in the optimal conditions shows a Poisson distribution with a mean value at $1.15 nm.