Synthesis of MWCNT Forests with Alumina-Supported Fe2O3 Catalyst by Using a Floating Catalyst Chemical Vapor Deposition Technique

In this study, multiwalled CNT bundles were synthesized with an alumina-supported Fe2O3 catalyst by using a floating catalyst chemical vapor deposition (FCCVD) technique. The metal catalyst was synthesized by dispersing Fe2O3 on alumina support. Ethylene molecules were decomposed over different amounts of metal nanoparticles in a FCCVD reactor. The CVD temperature was elevated from 600°C to 1000°C. The large active surface area of the metal nanobuds promoted the decomposition of a carbon precursor and the fast growth of CNT bundles. Least dense bundles of varying heights were observed at lower CVD temperatures of 600°C and 700°C. At 800°C, CVD process conditions were found suitable for the fast decomposition of hydrocarbon. The relatively better yield of well-structured CNTs was obtained with a catalyst weight of 0.3 g at 800°C. Above 800°C, CNT forests start losing alignment and height. The forest density was also decreased at temperatures above the optimum. The elemental composition of CNT bundles revealed the presence of carbon, aluminium, oxygen, and iron in percentages of 91%, 0.76%, 8.2%, and 0.04%, respectively. A very small ID to IG ratio of 0.22 was calculated for CNTs grown under optimized conditions.

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Stack growth of aligned multiwalled carbon nanotubes using floating catalyst chemical vapor deposition technique

Chemical Physics Letters ◽

10.1016/j.cplett.2015.02.036 ◽

2015 ◽

Vol 625 ◽

pp. 53-57

Author(s):

Mohamed Shuaib Mohamed Saheed ◽

Norani Muti Mohamed

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor Deposition ◽

Multiwalled Carbon Nanotubes ◽

Vapor Deposition ◽

Chemical Vapor ◽

Deposition Technique ◽

Multiwalled Carbon ◽

Chemical Vapor Deposition Technique ◽

Vapor Deposition Technique ◽

Catalyst Chemical Vapor Deposition

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Continuous synthesis of multiwalled carbon nanotubes from xylene using the swirled floating catalyst chemical vapor deposition technique

Journal of Materials Research ◽

10.1557/jmr.2010.69 ◽

2011 ◽

Vol 26 (5) ◽

pp. 640-644 ◽

Cited By ~ 14

Author(s):

Clarence S. Yah ◽

Sunny E. Iyuke ◽

Geoffrey S. Simate ◽

Emmanuel I. Unuabonah ◽

Graham Bathgate ◽

...

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor Deposition ◽

Multiwalled Carbon Nanotubes ◽

Vapor Deposition ◽

Chemical Vapor ◽

Deposition Technique ◽

Multiwalled Carbon ◽

Vapor Deposition Technique ◽

Image Position ◽

Catalyst Chemical Vapor Deposition

Abstract

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Synthesis of Boron-Doped Silicon Film Using Hot Wire Chemical Vapor Deposition Technique

Crystals ◽

10.3390/cryst10040237 ◽

2020 ◽

Vol 10 (4) ◽

pp. 237

Author(s):

M. Abul Hossion ◽

B. M. Arora

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Polycrystalline Silicon ◽

Silicon Film ◽

Chemical Vapor ◽

Hot Wire ◽

Deposition Technique ◽

Boron Doped ◽

Vapor Deposition Technique ◽

Polycrystalline Silicon Film

Boron-doped polycrystalline silicon film was synthesized using hot wire chemical vapor deposition technique for possible application in photonics devices. To investigate the effect of substrate, we considered Si/SiO2, glass/ITO/TiO2, Al2O3, and nickel tungsten alloy strip for the growth of polycrystalline silicon films. Scanning electron microscopy, optical reflectance, optical transmittance, X-ray diffraction, and I-V measurements were used to characterize the silicon films. The resistivity of the film was 1.3 × 10−2 Ω-cm for the polycrystalline silicon film, which was suitable for using as a window layer in a solar cell. These films have potential uses in making photodiode and photosensing devices.

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Impedance Spectroscopic Study of Nickel Sulfide Nanostructures Deposited by Aerosol Assisted Chemical Vapor Deposition Technique

Nanomaterials ◽

10.3390/nano11051105 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1105

Author(s):

Sadia Iram ◽

Azhar Mahmood ◽

Muhammad Fahad Ehsan ◽

Asad Mumtaz ◽

Manzar Sohail ◽

...

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Nickel Sulfide ◽

Variable Temperature ◽

Complex Impedance ◽

Equivalent Circuit Model ◽

Chemical Vapor ◽

Relaxation Processes ◽

Impedance Plot ◽

Vapor Deposition Technique

This research aims to synthesize the Bis(di-isobutyldithiophosphinato) nickel (II) complex [Ni(iBu2PS2)] to be employed as a substrate for the deposition of nickel sulfide nanostructures, and to investigate its dielectric and impedance characteristics for applications in the electronic industry. Various analytical tools including elemental analysis, mass spectrometry, IR, and TGA were also used to further confirm the successful synthesis of the precursor. NiS nanostructures were grown on the glass substrates by employing an aerosol assisted chemical vapor deposition (AACVD) technique via successful decomposition of the synthesized complex under variable temperature conditions. XRD, SEM, TEM, and EDX methods were well applied to examine resultant nanostructures. Dielectric studies of NiS were carried out at room temperature within the 100 Hz to 5 MHz frequency range. Maxwell-Wagner model gave a complete explanation of the variation of dielectric properties along with frequency. The reason behind high dielectric constant values at low frequency was further endorsed by Koops phenomenological model. The efficient translational hopping and futile reorientation vibration caused the overdue exceptional drift of ac conductivity (σac) along with the rise in frequency. Two relaxation processes caused by grains and grain boundaries were identified from the fitting of a complex impedance plot with an equivalent circuit model (Rg Cg) (Rgb Qgb Cgb). Asymmetry and depression in the semicircle having center present lower than the impedance real axis gave solid justification of dielectric behavior that is non-Debye in nature.

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