Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi

Zinc oxide (ZnO) nanostructures on gold-seeded silicon (Si) substrate were prepared using a low-temperature solution-immersion method. Optimised ZnO structures were then used as a template to grow a second layer of ZnO nanostructures by mist-atomisation method. Low-dimensional, vertically-aligned Zn...

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Main Author:	Khusaimi, Zuraida
Format:	Thesis
Language:	English
Published:	2012
Subjects:	Indexes (General) Physical and theoretical chemistry Analytical chemistry
Online Access:	https://ir.uitm.edu.my/id/eprint/40006/1/40006.pdf
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spelling	my-uitm-ir.400062023-01-19T08:04:59Z Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi 2012 Khusaimi, Zuraida Indexes (General) Physical and theoretical chemistry Analytical chemistry Zinc oxide (ZnO) nanostructures on gold-seeded silicon (Si) substrate were prepared using a low-temperature solution-immersion method. Optimised ZnO structures were then used as a template to grow a second layer of ZnO nanostructures by mist-atomisation method. Low-dimensional, vertically-aligned ZnO nanorods were successfully synthesised by the solution-immersion method through optimisation of the reaction parameters, such as concentration of precursor, ratio of stabiliser, alignment of substrate in solution, heating medium, gold-seeded substrates and its thickness, transition metal-seeded substrates, immersion temperature and time, pH of precursor solution, annealing temperature and doping with Mg. SEM, FESEM, TGA, FTIR, XRD, EDX, PL-Raman and I-V were the selected characterisation tools to analyse the structural, morphological, bonding, optical and electrical properties of the nanostructures. TGA and FTIR analyses gave evidence that the prepared ZnO nanostructures were pure with no traces of starting material or contamination. The results give evidence that 6 nm thickness of gold-seeded on Si substrate immersed for 4 hours at 70°C in precursor concentration of 0.005 - 0.05 M zinc nitrate hexahydrate (Zn(N03)2.6H20) and hexamethylenetetramine (HMTA) at 1:1 ratio has successfully formed (002) plane, c-axis, aligned ZnO nanorods with diameter of approximately 60 ± 20 nm. The nanorods prepared at low immersion temperatures were found to be readily crystalline with no additional heat treatment. Precursor solution of pH 6.8 and 5 produced ZnO nanorods, while at pH 9 produced ZnO flower-like structures. 1 atomic % of Mg-doped ZnO nanorods were found to produce the highest electrical conductivity relative to as-prepared ZnO, and higher doping content of 3, 5, 7 and 9 atomic %. PL emission spectra of ZnO nanorods consistently produced UV (362-388 nm) and visible emissions (400-800 nm), confirming the formation of a semi-conducting ZnO. The relevant chemical equations were suggested throughout the study, while a novel growth mechanism of ZnO nanorods on gold-seeded Si was proposed. The optimised thin-film of ZnO nanorods was applied as a seeding template for the growth of ZnO nanoparticles deposited by mist-atomisation method, and was found to form the smallest crystallite size of 6.34 nm at substrate temperature of 400°C. The chamber box, which was specially designed to contain the mist, was found to be practical, functional and an effective invention. The mist-atomisation deposition of ZnO produced nanogranular structures in the range of 50-120 nm. 2012 Thesis https://ir.uitm.edu.my/id/eprint/40006/ https://ir.uitm.edu.my/id/eprint/40006/1/40006.pdf text en public phd doctoral Universiti Teknologi MARA (UiTM) Faculty of Applied Sciences Mahmood, Mohamad Rusop
institution	Universiti Teknologi MARA
collection	UiTM Institutional Repository
language	English
advisor	Mahmood, Mohamad Rusop
topic	Indexes (General) Physical and theoretical chemistry Analytical chemistry
spellingShingle	Indexes (General) Physical and theoretical chemistry Analytical chemistry Khusaimi, Zuraida Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
description	Zinc oxide (ZnO) nanostructures on gold-seeded silicon (Si) substrate were prepared using a low-temperature solution-immersion method. Optimised ZnO structures were then used as a template to grow a second layer of ZnO nanostructures by mist-atomisation method. Low-dimensional, vertically-aligned ZnO nanorods were successfully synthesised by the solution-immersion method through optimisation of the reaction parameters, such as concentration of precursor, ratio of stabiliser, alignment of substrate in solution, heating medium, gold-seeded substrates and its thickness, transition metal-seeded substrates, immersion temperature and time, pH of precursor solution, annealing temperature and doping with Mg. SEM, FESEM, TGA, FTIR, XRD, EDX, PL-Raman and I-V were the selected characterisation tools to analyse the structural, morphological, bonding, optical and electrical properties of the nanostructures. TGA and FTIR analyses gave evidence that the prepared ZnO nanostructures were pure with no traces of starting material or contamination. The results give evidence that 6 nm thickness of gold-seeded on Si substrate immersed for 4 hours at 70°C in precursor concentration of 0.005 - 0.05 M zinc nitrate hexahydrate (Zn(N03)2.6H20) and hexamethylenetetramine (HMTA) at 1:1 ratio has successfully formed (002) plane, c-axis, aligned ZnO nanorods with diameter of approximately 60 ± 20 nm. The nanorods prepared at low immersion temperatures were found to be readily crystalline with no additional heat treatment. Precursor solution of pH 6.8 and 5 produced ZnO nanorods, while at pH 9 produced ZnO flower-like structures. 1 atomic % of Mg-doped ZnO nanorods were found to produce the highest electrical conductivity relative to as-prepared ZnO, and higher doping content of 3, 5, 7 and 9 atomic %. PL emission spectra of ZnO nanorods consistently produced UV (362-388 nm) and visible emissions (400-800 nm), confirming the formation of a semi-conducting ZnO. The relevant chemical equations were suggested throughout the study, while a novel growth mechanism of ZnO nanorods on gold-seeded Si was proposed. The optimised thin-film of ZnO nanorods was applied as a seeding template for the growth of ZnO nanoparticles deposited by mist-atomisation method, and was found to form the smallest crystallite size of 6.34 nm at substrate temperature of 400°C. The chamber box, which was specially designed to contain the mist, was found to be practical, functional and an effective invention. The mist-atomisation deposition of ZnO produced nanogranular structures in the range of 50-120 nm.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Khusaimi, Zuraida
author_facet	Khusaimi, Zuraida
author_sort	Khusaimi, Zuraida
title	Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
title_short	Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
title_full	Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
title_fullStr	Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
title_full_unstemmed	Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi
title_sort	synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / zuraida khusaimi
granting_institution	Universiti Teknologi MARA (UiTM)
granting_department	Faculty of Applied Sciences
publishDate	2012
url	https://ir.uitm.edu.my/id/eprint/40006/1/40006.pdf
_version_	1783734551165534208

Synthesis and characterisation of low-dimensional zinc oxide nanostructures by solutionimmersion and mist-atomisation / Zuraida Khusaimi

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