Growth and characterization of carbon nanostructures on zinc oxide nanostructures
type: CreativeWork
description: The research work of this thesis is aimed to explore the possibility to synthesize different hybrid materials based on ZnO and carbon hierarchical nanostructures, and to test their performances when used as chemiresistors to detect low doses (~ ppm) of polluting gases, like ammonia and acetone. Nanostructures of ZnO and carbon, including carbon nanotubes, exhibit on their own exceptional qualities, which can be enhanced when they are combined in hybrids, extending their possible practical applications further. In this thesis it is shown that, it is possible to grow different CNs/ZnO hybrid nanostructures which present higher sensitivity to ammonia if compared to other carbon-based and ZnO-based chemiresistors. The hybrids have been grown by combining different growth techniques, like magnetron sputtering, hydrothermal process, electron beam deposition and chemical vapour deposition. The grown samples were studied by using a variety of experimental techniques, also in-situ, which allowed us to deeply understand their structural and chemical properties. In particular the chemical analysis was done by ultra violet and X-ray photoelectron spectroscopy (UPS and XPS, respectively, also using synchrotron radiation), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX). The morphology of the samples have been analysed, ex-situ, by scanning electron microscopy (SEM) and their fine atomic structure by high resolution transmission electron microscopy (HRTEM). The synthesis of aligned ZnO nanorods was done following the procedure below. Zinc oxide films were first deposited on Si <100> substrates using DC magnetron 4 sputtering at different chamber pressures, using oxygen to fully oxidize the films. Vertically oriented ZnO nanorods were then grown using the hydrothermal method on the resultant films. The pristine ZnO films were characterized by SEM, AFM, EDX and XRD. The films transparency and grain size were found to be pressure dependent: as the pressure was incr…
abstract: The research work of this thesis is aimed to explore the possibility to synthesize different hybrid materials based on ZnO and carbon hierarchical nanostructures, and to test their performances when used as chemiresistors to detect low doses (~ ppm) of polluting gases, like ammonia and acetone. Nanostructures of ZnO and carbon, including carbon nanotubes, exhibit on their own exceptional qualities, which can be enhanced when they are combined in hybrids, extending their possible practical applications further. In this thesis it is shown that, it is possible to grow different CNs/ZnO hybrid nanostructures which present higher sensitivity to ammonia if compared to other carbon-based and ZnO-based chemiresistors. The hybrids have been grown by combining different growth techniques, like magnetron sputtering, hydrothermal process, electron beam deposition and chemical vapour deposition. The grown samples were studied by using a variety of experimental techniques, also in-situ, which allowed us to deeply understand their structural and chemical properties. In particular the chemical analysis was done by ultra violet and X-ray photoelectron spectroscopy (UPS and XPS, respectively, also using synchrotron radiation), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX). The morphology of the samples have been analysed, ex-situ, by scanning electron microscopy (SEM) and their fine atomic structure by high resolution transmission electron microscopy (HRTEM). The synthesis of aligned ZnO nanorods was done following the procedure below. Zinc oxide films were first deposited on Si <100> substrates using DC magnetron 4 sputtering at different chamber pressures, using oxygen to fully oxidize the films. Vertically oriented ZnO nanorods were then grown using the hydrothermal method on the resultant films. The pristine ZnO films were characterized by SEM, AFM, EDX and XRD. The films transparency and grain size were found to be pressure dependent: as the pressure was incr…
author: Mbuyisa, Puleng Nontobeko
keywords: Nanostructures
license: https://devspace.unizulu.ac.za/bitstreams/31785338-a7ee-48eb-8ba8-f001d43eb5be/download
date published: 2012
date modified: 2026-07-24T06:17:11Z
provider: University of Zululand
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Zululand