Carbon nanotube and nanofiber growth on Zn based catalysts

In this study, acetylene gas was delivered to a catalyst network consists of NaCl-support and Zn nanoparticles in a temperature range of 500-700°C by means of a chemical vapor deposition (CVD). A principle feature that delineated this CVD study from prior studies lay, first in the method used to support the catalyst and secondly the choice of the catalyst metal. In particular, NaCl was deliberately retained and exploited in subsequent manipulations for the reason that it performed remarkably well as a support medium. The catalytic activity of Zn towards production of CNT/CNFs appeared to be promoted as a result of using molten ionic substrate

Multilayer Graphene Synthesized by CVD Using Liquid Hexane as the Carbon Precursor

We produce multilayer graphene by the Chemical Vapor Deposition (CVD) method at atmospheric pressure and 1000 {\deg}C, using flexible copper substrates as catalyst and liquid hexane as the source of carbon. We designed an optical device to measure the transmittance of the carbon films; with this information we calculate that the approximate number of layers is 11.Comment: 6 pages, 5 figures. Accepted for publication in World Journal of Condensed Matter Physic

A simple method to build catalyst layers for the synthesis of vertically aligned carbon nanotubes

Nowadays, environmental protection and sustainability are getting more and more attention. Thus, our aim was to develop a cost and energy efficient catalyst layer building method for the synthesis of carbon nanotube forests. A simple spray coating method was used to develop a catalyst layer on the surface of the titanium substrates. Then vertically aligned carbon nanotubes (VACNTs) were synthesized directly on the substrate via catalytic chemical vapor deposition (CCVD) method. During our research, the effect of catalyst layer deposition parameters on the structure of CNTs was investigated and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy

InN nanowires: Growth and optoelectronic properties

An overview on InN nanowires, fabricated using either a catalyst-free molecular beam epitaxy method or a catalyst assisted chemical vapor deposition process, is provided. Differences and similarities of the nanowires prepared using the two techniques are presented. The present understanding of the growth and of the basic optical and transport properties is discussed

Optimization of Iron (III) Oxide Catalyst Using Taguchi Method for Development of Carbon Nanofiber

Carbon nanofiber (CNF) has widely developed due to its potential application in hydrogen storage material in solid form. CNF is synthesized from the chemical vapor deposition (CVD) of carbon containing gasses over transition metal of the catalyst. The size of catalyst will control the type of CNF produced. This research work is to find the most optimum condition for Iron (III) oxide in developed catalyst using Taguchi Method as the design of experiment

Molecular Dynamics Study of the Catalyst Particle Size Dependence on Carbon Nanotube Growth

The molecular dynamics method, based on an empirical potential energy surface, was used to study the effect of catalyst particle size on the growth mechanism and structure of single-walled carbon nanotubes (SWNTs). The temperature for nanotube nucleation (800-1100 K), which occurs on the surface of the cluster, is similar to that used in catalyst chemical vapor deposition experiments, and the growth mechanism, which is described within the vapor-liquid-solid model, is the same for all cluster sizes studied here (iron clusters containing between 10 and 200 atoms were simulated). Large catalyst particles, that contain at least 20 iron atoms, nucleate SWNTs and have a far better tubular structure than SWNTs nucleated from smaller clusters. In addition, the SWNTs that grow from the larger clusters have diameters that are similar to the cluster diameter, whereas the smaller clusters, which have diameters less than 0.5 nm, nucleate nanotubes that are approximately 0.6-0.7 nm in diameter. This is in agreement with the experimental observations that SWNT diameters are similar to the catalyst particle diameter, and that the narrowest free-standing SWNT is 0.6-0.7 nm

Controlled Synthesis and Characterization of Metal Oxide Nanowires by Chemical Vapor Deposition on Silicon and Carbon Substrates

Nanotechnology and nanomaterials have attracted considerable interest and are predicted to revolutionize many materials and technologies that we use in everyday life. In the past few years, significant research has focused on one dimensional metal oxide nanostructures due to their unique properties and potential applications in various fields from nanoelectronics to energy. However, controlled synthesis of these nanostructures is still a challenge. The objective of this thesis is to synthesize metal oxide nanowires by chemical vapour deposition directly on various substrates. The nanostructures include (i) silicon oxide nanostructures on silicon substrate, (ii) manganese oxide nanostructures on silicon substrate, and (iii) manganese oxide nanostructures on carbon paper substrate. Firstly, silicon oxide nanowires were synthesized on silicon substrate by a VO2 assisted chemical vapor deposition. Networked features of silicon oxide nanowires were found. Systematic study on the nanowire growth has indicated that morphology and composition of the final products are considerably sensitive to the catalyst components, reaction atmosphere and temperature. These results will help in better understanding the growth process of silicon oxide nanowires. Secondly, manganese oxide nanostructures were synthesized on silicon substrate by chemical vapor deposition method. It was found that MnO nanowires are high density and single crystalline with average diameter of 150 nm. These nanowires were characterized using FESEM, EDX, TEM and XRD. The synthesis process and effects of growth parameters such as temperature, heating rate and source/substrate distance on the morphology, composition and structure of the products were systematically studied. Finally, manganese oxide nanostructures were synthesized on carbon paper substrate by chemical vapor deposition method. It was revealed that manganese oxide nanowires and nanobelts can be selectively grown on carbon paper substrate by using a catalyst (gold) assisted or catalyst free thermal evaporation of manganese powder under an argon gas atmosphere. Various effects of growth parameters such as temperature, catalyst and buffered substrate on the growth product were also systematically investigated by using SEM, TEM and XPS

Controlled Synthesis and Characterization of Metal Oxide Nanowires by Chemical Vapor Deposition on Silicon and Carbon Substrates

Nanotechnology and nanomaterials have attracted considerable interest and are predicted to revolutionize many materials and technologies that we use in everyday life. In the past few years, significant research has focused on one dimensional metal oxide nanostructures due to their unique properties and potential applications in various fields from nanoelectronics to energy. However, controlled synthesis of these nanostructures is still a challenge. The objective of this thesis is to synthesize metal oxide nanowires by chemical vapour deposition directly on various substrates. The nanostructures include (i) silicon oxide nanostructures on silicon substrate, (ii) manganese oxide nanostructures on silicon substrate, and (iii) manganese oxide nanostructures on carbon paper substrate. Firstly, silicon oxide nanowires were synthesized on silicon substrate by a VO2 assisted chemical vapor deposition. Networked features of silicon oxide nanowires were found. Systematic study on the nanowire growth has indicated that morphology and composition of the final products are considerably sensitive to the catalyst components, reaction atmosphere and temperature. These results will help in better understanding the growth process of silicon oxide nanowires. Secondly, manganese oxide nanostructures were synthesized on silicon substrate by chemical vapor deposition method. It was found that MnO nanowires are high density and single crystalline with average diameter of 150 nm. These nanowires were characterized using FESEM, EDX, TEM and XRD. The synthesis process and effects of growth parameters such as temperature, heating rate and source/substrate distance on the morphology, composition and structure of the products were systematically studied. Finally, manganese oxide nanostructures were synthesized on carbon paper substrate by chemical vapor deposition method. It was revealed that manganese oxide nanowires and nanobelts can be selectively grown on carbon paper substrate by using a catalyst (gold) assisted or catalyst free thermal evaporation of manganese powder under an argon gas atmosphere. Various effects of growth parameters such as temperature, catalyst and buffered substrate on the growth product were also systematically investigated by using SEM, TEM and XPS