We report a novel, scaleable and versatile method for large scale synthesis of tungsten trioxide nanowires and their arrays on a variety of substrates including amorphous quartz, fluorinated tin oxide, etc. The synthesis concept uses the chemical vapor transport of metal oxide vapor phase species onto substrates using air or oxygen flow over hot-filament sources. The hot-filaments were designed...

In order to utilize nanostructured materials for potential solar and other energy-harvesting applications, scalable synthetic techniques for these materials must be developed. Herein we use a vapor phase conversion approach to synthesize nanowire (NW) arrays of semiconducting barium silicide (BaSi2) in high yield for the first time for potential solar applications. Dense arrays of silicon NWs o...

monometallic and bimetallic ni and co catalytic nanoparticles supported on titanium dioxide (rutile phase) substrate were prepared by wet impregnation method. these nanoparicles were used as catalysts for synthesis of multiwalled carbon nanotubes (mwcnts) from acetylene decomposition at 700°c by the catalytic chemical vapor deposition (ccvd) technique. the nanomaterials (catalyst and cnts) were...

bamboo-structured carbon nanotubes are grown on co-mo/mcm-41 catalyst in the temperature range of 873-973 k by thermal chemical vapor deposition of acetylene. this study shows that the purified carbon nanotubes have open tips and the metals of the catalyst are not encapsulated. thus, the bamboo-structure seems to grow from the base. pore size distribution of the product is quite narrow and is i...

thin films of sno2 nanowires were successfully prepared by using chemical vapor deposition (cvd) process on quartz substrates. afterwards, a thin  layer of palladium (pd) as a catalyst was coated on top of nanowires. for the deposition of pd, a simple and low cost technique of spray pyrolysis was employed, which caused an intensive enhancement on the sensing response of fabricated sensors. prep...

carbon nanotubes were synthesized over a series of zn-containing fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °c using methane as a carbon source. catalysts were synthesized by keeping fe concentration constant and varying zn concentration to study the effects of zn. the catalysts were characterized using x – ray powder diffraction and n2 ...

the growth rate of carbon nanotubes in chemical vapor deposition is simulated by using a theoretical analysis of the phonon vibration of the system. simulations demonstrate that the growth rate of carbon nanotubes with larger diameters is smaller because of higher damping factors and carbon nanotube inertia. an optimum temperature for the growth rate is calculated for a carbon nanotube on fe ca...

in this study, we describe the growth of carbon nanotubes on commercial iron nanoparticles without carbon shell (fe (nm), size 2o3 and fe* (nm)/mgo) was carried out by mixing commercial fe* nanoparticles (as catalyst) with al2o3 and mgo powders (as supports)by using ball-milling method. the results show in spite of the fact that ball-milling process can have negative effects on diameter and mor...

chemical vapor deposition was employed to synthesize carbon nanotubes with ni-loaded mcm-41 and mcm-48 as catalysts and acetylene as precursor at 750°c. mesoporous ni mcm-41 and ni mcm-48 molecular sieves were synthesized by a hydrothermal method and were characterized by xrd and n2 adsorption isotherm. the catalytically synthesized carbon materials were characterized with raman spectroscopy, n...

This paper is an attempt to synthesize nanostructured tantalum films on medical grade AISI 316L stainless steel (SS) using pulsed DC plasma assisted chemical vapor deposition (PACVD). The impact of duty cycle (17-33%) and total pressure (3-10 torr) were studied using field emission scanning electron microscopy (FESEM), grazing incidence x-ray diffraction (GIXRD), nuclear reaction analysis (NRA)...