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Synthesis and Application of Two Dimensional Non- Layered Nanomaterials Derived from Liquid Gallium

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Synthesis and Application of Two Dimensional Non- Layered Nanomaterials Derived from Liquid Gallium Synthesis and application of two dimensional non- layered nanomaterials derived from liquid gallium A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Nitu Syed M.Sc. (Electrical and Electronic Engineering), Bangladesh University of Engineering and Technology B. Sc. (Electrical and Electronic Engineering), Bangladesh University of Engineering and Technology School of Engineering College of Science, Engineering and Health RMIT University August 2019 Declaration I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for any other academic award; the content of the thesis is the result of work which has been carried out since the official commencement date of the approved research program; any editorial work, paid or unpaid, carried out by a third party is acknowledged; and, ethics procedures and guidelines have been followed. I acknowledge the support I have received for my research through the provision of an Australian Government Research Training Program Scholarship. Nitu Syed 15/08/2019 ii Acknowledgements First and foremost, I would like to thank the almighty Allah to be the most gracious and merciful all through my life. I gratefully acknowledge the funding provided by RMIT University for awarding me with Vice-Chancellor's PhD Scholarship (VCPS) and School of Engineering for the top up scholarship. I would like to appreciate the support provided by Australian Research Council (ARC) and Centre for future low-energy electronics technologies (FLEET) for giving me the opportunity to participate in several valuable educational programs. I would like to convey my heartiest appreciation and sincere thanks to my honourable supervisors Dr. Torben Daeneke and Professor Chris McConville for providing me with the opportunity to undertake this exciting work. I am very thankful to Dr. Torben Daeneke for his invaluable inputs to my work, continuous guidance and encouragement throughout this PhD research. I would like to thank my another supervisor Dr. Dorna Esrafilzadeh (University of New South Wales) for her support and suggestions. I am indebted to Professor Kourosh Kalantar-Zadeh to whom I would like to express my heartfelt gratitude for not only being a great supervisor during my first two years of PhD but also for playing the role of a great mentor in this tough journey. His constant scientific inputs as well as advice have gotten me to where I am today. My deep appreciation also goes out to Dr. Jian Zhen Ou and Dr. Ali Zavabeti for their scientific advice and many insightful discussions. None of this research could have been conducted without the access to the world- class equipment and the expert staff of the RMIT Microscopy and Microanalysis Facility (RMMF), the Micro Nano Research Facility (MNRF) and RMIT chemistry laboratories. I have been privileged for the opportunity to work here. My sincere thanks to the iii approachable and supportive technical staff Dr. Zeyad Nasa, Dr. Chenglong Xu, Paul Jones and Dr. Edwin Mayes. This PhD would not have been possible without the collaboration and support of my co-authors and friends at RMIT University. I would particularly like to thank Md Mohiuddin, Azmira Jannat, Robi Datta, Nripen Dhar, Farjana Haque, Bao Yue Zhang, Naresh Pillai and Kibret Messalea. Thanks are due to all my friends, relatives, students and colleagues who always loved, inspired and supported me. I am grateful to my workplace Independent University, Bangladesh (#IUB) for granting my study leave and supporting me to pursue higher education. Last but not least, there are no words to convey my deepest gratitude to my family. I would like to express my deepest love and affection to my father Md Shahiduzzaman and my mother Begum Noorjahan with respect, for being the most supportive parents in the world. Their prayers for me are always the biggest strength of mine. Especially I can’t thank you enough Mom for encouraging me throughout this experience. I would like to acknowledge my younger sister Nabila Sayed for taking care of my family while I am away from home. My beloved daughter Samarah, has always kept me in sheer happiness. Lastly, my beloved husband, Tanjib Rubaiyat, has been an endless torrent of encouragement, humour, patience, tolerance and love. Thank you for supporting me in every step throughout this tough journey and he deserves this Ph.D. just as much as I do. iv I dedicate this PhD thesis to my parents, my husband Tanjib Rubaiyat and my baby Samarah for their constant support and unconditional love. v Table of Contents Declaration ..................................................................................................................... ii Acknowledgements ............................................................................................................ iii Abstract ..................................................................................................................... x Publications ...................................................................................................................... xiii First-authored publications ....................................................................................... xiii Co-authored publications ......................................................................................... xiii List of Figures .................................................................................................................. xvi List of Tables ................................................................................................................ xxiv Abbreviations ................................................................................................................. xxv Chapter 1 ..................................................................................................................... 1 Motivations and objectives ............................................................................................... 1 1.1 Motivations .............................................................................................................. 1 1.2 Objectives ................................................................................................................ 5 1.2.1 Sonication assisted synthesis of gallium oxide suspensions featuring trap state absorption: test of photochemistry ...................................................................... 5 1.2.2 Printing two-dimensional gallium phosphate out of liquid metal .................. 6 1.2.3 Synthesis of centimetre-scale ultra-thin 2D gallium nitride nanosheets from liquid metal derived oxide layer .................................................................................. 7 1.3 Organisation of thesis ............................................................................................... 8 1.4 References ............................................................................................................. 10 Chapter 2 ................................................................................................................... 15 Literature review ............................................................................................................ 15 vi 2.1 Introduction ............................................................................................................ 15 2.2 Two-dimensional (2D) materials .......................................................................... 16 2.3 Gallium and gallium compounds .......................................................................... 19 2.3.1 Gallium .......................................................................................................... 19 2.3.2 Gallium compounds ....................................................................................... 21 2.3.2.1 Gallium oxide (Ga2O3) ............................................................................... 21 2.3.2.2 Gallium mono-chalcogenides (GaX) .......................................................... 22 2.3.2.3 Gallium nitride (GaN) ................................................................................. 23 2.3.2.4 Gallium phosphate (GaPO4) ....................................................................... 25 2.4 Potential of liquid metals ...................................................................................... 26 2.4.1 Fundamental properties of bulk liquid metals ............................................... 26 2.4.2 Surface properties of liquid metal ................................................................. 27 2.4.3 Applications of liquid metal ......................................................................... 30 2.4.4 Liquid metal surface as a reaction medium for synthesizing 2D materials ... 31 2.4.4.1 Liquid based exfoliation of 2D nanostructures from liquid metal interface................................................................................................................... 31 2.4.4.2 Synthesis of large-area 2D nanosheets using liquid metal reaction media 32 2.5 Summary ............................................................................................................... 34 2.6 References ............................................................................................................. 35 Chapter 3 ................................................................................................................... 44 Sonication
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