Download or read book Controlled Growth and Characterization of One dimensional Nano structured Materials written by Yongfu Qiu and published by . This book was released on 2008 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of One and Two dimensional Novel Nanomaterials written by Yu Zhong (Ph.D.) and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials have attracted extensive interest due to their unique structure and excellent properties compared with their bulk counterparts. To obtain nanodevices with controlled properties, it is prerequisite to synthesize nanostructured materials with designed architecture. In this work, low (one- and two- ) dimensional nanomaterials with controlled structures have been synthesized and characterized based on chemical vapour deposition strategy. Our research targets cover one-dimensinoal hollow, solid, and solid @ hollow heterostructural nanomaterials including carbon nanotubes (CNTs), nitrogen-doped carbon nanotubes (NCNTs), SnO2 nanowires, Mo doped-SnO2 nanowires, Sn nanowires encapsulated in CNTs (Sn@CNTs), and two-dimensional Mo2S3 nanopetals. Dependence of product morphology, composition and phase structure on the synthesis conditions has been systematically investigated by changing temperature, growth time, gas flow, external atom doping, catalyst and employed substrate, to get insight into the correlation between the structure control and growth conditions of the products and their growth mechanism as well. High quality CNTs and NCNTs with uniform size were synthesized on carbon paper and Si wafer by introducing thin iron sputtering film as catalyst. High nitrogen content up to 10.4 at% was reached in the NCNTs. Controlled growth of SnO2 and Mo-doped SnO2 nanowires was obtained on different substrates including carbon paper, stainless steel and Cu to meet substrate requirements for practical applications. It was found that Mo doping could significantly improve the corrosion resistance of the SnO2 nanowires. Core-shell heterostructures of Sn nanowires @ CNTs were produced on carbon microfibers, stainless steel and Cu substrates. Rational control on the thickness and nature of the carbon shell of the heterostructures on carbon microfibers was realized by modulating growth parameters and introducing extra catalyst. Multi-generation Sn@CNTs were obtained by exploring SnO and SnO2 as starting materials. On the metallic substrates, Sn-alloy@CNT nanostructures were obtained. In another way, SnCo alloy nanowires @ CNTs with readily controlled Co content were achieved by introducing cobalt-contained precursor. Non-catalytic and catalytic growth of two-dimensional Mo2S3 nanopetals was investigated on carbon microfibers. Without catalyst, the nanopetals with high density were only obtained in a narrow range of the precursor concentration. With Au catalyst, uniform nanopetals with steady high density could be achieved in a wide range of the precursor concentration. Morphology, composition and phase structure of the nanostructures were characterized and analyzed by electron microscopy, X-ray diffraction, energy-dispersed spectroscopy and Raman spectroscopy.
Download or read book One Dimensional Nanostructures written by Zhiming M Wang and published by Springer Science & Business Media. This book was released on 2008-07-20 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-dimensional (1D) nanostructures, including nanowires, nanotubes and quantum wires, have been regarded as the most promising building blocks for nanoscale electronic and optoelectronic devices. This book presents exciting, state-of-the-art developments in synthesis and properties of 1D nanostructures with many kinds of morphologies and compositions as well as their considerable impact on spintronics, information storage, and the design of field-effect transistors.
Download or read book Controlled Growth Of Nanomaterials written by Lide Zhang and published by World Scientific. This book was released on 2007-11-12 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the latest methods for the controlled growth of nanomaterial systems. The coverage includes simple and complex nanomaterial systems, ordered nanostructures and complex nanostructure arrays, and the essential conditions for the controlled growth of nanostructures with different morphologies, sizes, compositions, and microstructures. The book also discusses the dynamics of controlled growth and thermodynamic characteristics of two-dimensional nanorestricted systems. The authors introduce various novel synthesis methods for nanomaterials and nanostructures, such as hierarchical growth, heterostructures growth, doping growth and some developing template synthesis methods. In addition to discussing applications, the book reviews developing trends in nanomaterials and nanostructures.
Download or read book Controlled Synthesis of One Dimensional Nanostructured Materials and Their Applications as Catalyst Supports in Proton Exchange Membrane Fuel Cells written by Mohammad Norouzi Banis and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials have attracted significant interest in the past decade due to their unique structure and properties compared to their bulk counterparts. Nanomaterials-based solutions can address challenges in various technologies such as proton exchange membrane fuel cells (PEMFCs). PEMFC is an innovative energy conversion technology to directly convert chemical energy to electrical energy by using hydrogen as fuel. However, the current PEMFC system still faces significant technological roadblocks which have to be overcome before the system can become economically viable. A major impediment to the commercialization of PEMFC is the high cost of materials and manufacturing and stability, which is primarily associated with the cost of Pt catalysts and their support in membrane electrode assembly (MEA). One approach in addressing these issues is the controlled synthesis and application of nanostructured Pt-based catalysts and their support in PEMFCs. The objective of this thesis is to synthesize and characterize various nanostructures (e.g. metal oxides and metal silicides or composites) and evaluate their performance as Pt supports used in the PEMFCs. Various advanced characterization techniques such as high resolution scanning and transmission electron microscopy, X-ray absorption spectroscopy and electrochemical characterization methods have been used to understand growth mechanism of obtained nanostructures and their roles in PEMFCs. We also reported the synthesis of WSi2 and Ta5Si3 heterostructures using a low pressure chemical vapor deposition (LPCVD) method. The morphologies of these nanostructures were found to be sensitive to the concentration of reactive species and silica vapor in the CVD chamber. The results indicated that the morphology of WSi2 and Ta5Si3 nanostructures varied from nanowires, networked nanoribbons to nanosheets with the control of the oxygen concentration. A vapor solid growth mechanism based on silica sheath formation was proposed for the synthesis of these nanostructures. To take advantage of unique properties of carbon nanotubes, metal oxide and metal silicides as catalyst support, a new method was developed for the synthesis of composite nanostructures. TiSi2Ox-NCNTs and TiO2-NCNTs nanocomposites were synthesized using a combination of CVD process and magnetron sputtering and their performance as catalyst supports in PEMFCs were studied. Pt nanoparticles deposited on these nanostructures showed enhanced catalytic activity compared to commercial Pt/carbon electrodes. The electronic structure of Pt on the catalyst supports was investigated using X-ray absorption spectroscopy, to obtain insight into the interaction between the catalyst supports and Pt nanoparticles. As an example of well controlled synthesis of nanostructures, one-dimensional tungsten oxide nanostructures (W18O49) have been synthesized using a conventional chemical vapor deposition method (CVD). The morphology of the nanostructures such as diameter and length, were controlled during the synthesis process via sulfur doping. The dependence of morphology, composition and structure of tungsten oxides on the sulfur flow rate has been studied. Further, one step synthesis of tungsten sulfide/tungsten oxide nanocables (WS2/W18O49) have been achieved for the first time using tungsten and sulfur powder as the starting materials. In summary, the research work presented in this thesis aims at contributing to the development of various novel nanostructured catalyst supports and probing the correlation between synthesis approach, fine structure, and catalytic performance of the nanostructures as well as exploring their potential applications in highly active electrocatalysts for PEMFCs.
Download or read book Handbook of Nanophase and Nanostructured Materials Characterization written by Zhong Lin Wang and published by 清华大学出版社有限公司. This book was released on 2003 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: 纳米相和纳米结构材料是纳米科学和纳米技术的基础。纳米相和纳米结构材料手册是一套综述纳米学科在材料合成、结构和性能表征、理论模拟、实际应用和发展前沿的书籍。本书是这套丛书的第二本。书中内容详细阐述分析表征纳米材料的方法和技术。主要围绕表征技术在分析纳米材料原子结构和物理化学性能中的原理、数据分析过程和具体应用,并介绍了各种方法的最新进展和参考文献。
Download or read book Novel Synthesis and Characterization of Nanostructured Materials written by Annelise Kopp Alves and published by Springer Science & Business Media. This book was released on 2013-10-18 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured materials have been largely studied in the last few years. They have great potential of applications in different fields such as materials science, physics, chemistry, biology, mechanic and medicine. Synthesis and characterization of nanostructured materials is a subject of great interest involving science, market, politicians, government and society. Based on results obtained by the authors' research group during the past decade, this book comes to present novel techniques to synthesize nanostructured materials and characterize their properties such as crystallinity and crystallite size, specific surface area, particle size, morphology and catalytic activity. This book is aimed for students, researchers and engineers searching for methodologies to obtain and characterize nanostructures in details.
Download or read book Advanced Nano Deposition Methods written by Yuan Lin and published by John Wiley & Sons. This book was released on 2016-12-12 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This concise reference summarizes the latest results in nano-structured thin films, the first to discuss both deposition methods and electronic applications in detail. Following an introduction to this rapidly developing field, the authors present a variety of organic and inorganic materials along with new deposition techniques, and conclude with an overview of applications and considerations for their technology deployment.
Download or read book Nanotechnology for Biology and Medicine written by Gabriel A. Silva and published by Springer Science & Business Media. This book was released on 2011-10-22 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text book will bring together a mix of both internationally known and established senior scientists along side up and coming (but already accomplished) junior scientists that have varying expertise in fundamental and applied nanotechnology to biology and medicine.
Download or read book One Dimensional Nanostructures written by Tianyou Zhai and published by John Wiley & Sons. This book was released on 2012-10-19 with total page 857 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews the latest research breakthroughs and applications Since the discovery of carbon nanotubes in 1991, one-dimensional nanostructures have been at the forefront of nanotechnology research, promising to provide the building blocks for a new generation of nanoscale electronic and optoelectronic devices. With contributions from 68 leading international experts, this book reviews both the underlying principles as well as the latest discoveries and applications in the field, presenting the state of the technology. Readers will find expert coverage of all major classes of one-dimensional nanostructures, including carbon nanotubes, semiconductor nanowires, organic molecule nanostructures, polymer nanofibers, peptide nanostructures, and supramolecular nanostructures. Moreover, the book offers unique insights into the future of one-dimensional nanostructures, with expert forecasts of new research breakthroughs and applications. One-Dimensional Nanostructures collects and analyzes a wealth of key research findings and applications, with detailed coverage of: Synthesis Properties Energy applications Photonics and optoelectronics applications Sensing, plasmonics, electronics, and biosciences applications Practical case studies demonstrate how the latest applications work. Tables throughout the book summarize key information, and diagrams enable readers to grasp complex concepts and designs. References at the end of each chapter serve as a gateway to the literature in the field. With its clear explanations of the underlying principles of one-dimensional nanostructures, this book is ideal for students, researchers, and academics in chemistry, physics, materials science, and engineering. Moreover, One-Dimensional Nanostructures will help readers advance their own investigations in order to develop the next generation of applications.
Download or read book Low Dimensional and Nanostructured Materials and Devices written by Hilmi Ünlü and published by Springer. This book was released on 2019-03-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the fundamental phenomena at nanoscale. It covers synthesis, properties, characterization and computer modelling of nanomaterials, nanotechnologies, bionanotechnology, involving nanodevices. Further topics are imaging, measuring, modeling and manipulating of low dimensional matter at nanoscale. The topics covered in the book are of vital importance in a wide range of modern and emerging technologies employed or to be employed in most industries, communication, healthcare, energy, conservation , biology, medical science, food, environment, and education, and consequently have great impact on our society.
Download or read book Handbook of Nanophase and Nanostructured Materials written by Z.L. Wang and published by Springer Science & Business Media. This book was released on 2002-11-30 with total page 1519 pages. Available in PDF, EPUB and Kindle. Book excerpt: These books, with of a total of 40 chapters, are a comprehensive and complete introductory text on the synthesis, characterization, and applications of nanomaterials. They are aimed at graduate students and researchers whose background is chemistry, physics, materials science, chemical engineering, electrical engineering, and biomedical science. The first part emphasizes the chemical and physical approaches used for synthesis of nanomaterials. The second part emphasizes the techniques used for characterizing the structure and properties of nanomaterials, aiming at describing the physical mechanism, data interpretation, and detailed applications of the techniques. The final part focuses on systems of different nanostructural materials with novel properties and applications.
Download or read book Handbook of Nanophase and Nanostructured Materials Materials systems and applications II written by Zhong Lin Wang and published by 清华大学出版社有限公司. This book was released on 2003 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Nanoscale and Low Dimensional Materials and Devices written by Hilmi Ünlü and published by Springer Nature. This book was released on 2022-10-18 with total page 939 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes most recent progress in the properties, synthesis, characterization, modelling, and applications of nanomaterials and nanodevices. It begins with the review of the modelling of the structural, electronic and optical properties of low dimensional and nanoscale semiconductors, methodology of synthesis, and characterization of quantum dots and nanowires, with special attention towards Dirac materials, whose electrical conduction and sensing properties far exceed those of silicon-based materials, making them strong competitors. The contributed reviews presented in this book touch on broader issues associated with the environment, as well as energy production and storage, while highlighting important achievements in materials pertinent to the fields of biology and medicine, exhibiting an outstanding confluence of basic physical science with vital human endeavor. The subjects treated in this book are attractive to the broader readership of graduate and advanced undergraduate students in physics, chemistry, biology, and medicine, as well as in electrical, chemical, biological, and mechanical engineering. Seasoned researchers and experts from the semiconductor/device industry also greatly benefit from the book’s treatment of cutting-edge application studies.
Download or read book Growth Control and Manipulation of Morphology Crystallinity and Physical Properties of Tin IV Oxide Nanostructures written by Samad Bazargan and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of nanostructures of tin (IV) oxide (TO) are synthesized using two fabrication methods: a solution spin-coating method followed by post-annealing in an oxygen flow and a newly developed catalyst-assisted pulsed laser deposition (PLD) technique. The spin-coating method is used to fabricate granular TO films with monodisperse, stable, ultra-small nanocrystallites (4-5 nm in size), the size of which is found to increase exponentially with post-anneal above 500°C. These nanocrystalline films are conductive and highly transparent, and their bandgap shows broadening due to a high carrier concentration. Their resistivity behavior as a function of temperature in the 50-280 K range can be explained by a two-medium transport model, i.e. transport through the crystalline grains and across the grain boundaries, and through the charge-depletion layer, where a potential barrier is found for transport across the grain boundaries. Electronic transport in these films follows a 3D-variable range hopping model, which reveals an increase in the localization length of carriers with increasing the TAnneal above the onset of exponential growth at TAnneal= 500°C. By homogenously doping Eu3+ in these nanocrystalline films up to a high doping level of ~ 8%, optical luminescence and magnetic orderings can be introduced into these nanocrystalline TO films. Both characteristic Eu3+ emission and defect-related TO emissions are observed in the otherwise transparent TO films upon UV-excitation. In spite of the non-magnetic nature of Eu3+ ions, magnetic orderings appear in the highly doped TO films below 50 K upon the emergence of Eu2Sn2O7 phase. In the second part of this work, we employ a layer of gold nanoislands with controlled sizes (10-50 nm) as catalysts for pulsed laser deposition of TO nanostructures. Highly crystalline TO nanobricks, cuboid nanoparticles, nanowires and nanobelts are obtained for the first time through vapour-solid or vapour-liquid-solid (VLS) mechanisms. Of particular interest are the micron long one-dimensional (1D) nanowires and nanobelts, with the smallest square and rectangular cross-sections, respectively, ever reported. These single-crystalline nanostructures are obtained at relatively low temperatures of 600°C, for nanowires, and 500°C, for nanobelts, and their cross-sectional sizes can be easily controlled by the size of the gold nanoislands. The nanobelts are found to grow along the [100] and [101] axes, while the nanowires appear to grow along the [100] axis. The growth evolution of the nanobelts are also investigated in detail revealing their VLS growth mode and their single-crystalline structure throughout the growth, which opens the prospect of controlling their growth axis and consequently their side-surface planes by pinning the base to the substrate at the desired crystalline orientation. Together, the two fabrication methods developed in the present work offer facile approaches to growing two scientifically and technologically important classes of TO nanostructures, i.e., nanocrystalline film and 1D nanostructures. Thorough characterization of the resulted nanostructured materials using advanced microscopic, spectroscopic and other techniques, including Helium Ion Microscopy, has been provided. Modification of structure, morphology and physical properties of these functional nanostructured materials are also illustrated by controlling the growth parameters and by (Eu-)doping, which pave the way for introducing new properties for applications in chemical sensing, (opto)electronics and displays.
Download or read book PROCESSING AND ANALYSIS OF ONE DIMENSIONAL CARBON NANOSTRUCTURES written by Binh Duong and published by . This book was released on 2011 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fabrication and synthesis of nanostructured materials are essential aspects of nanoscience and nanotechnology. Although researchers are now able to create and tailor different nanostructured materials, the ability to precisely control the materials' sizes, shapes, and properties at the nanoscale level remains challenging. The aim of this dissertation was to develop new methods to aid researchers in overcoming these challenges. The study investigated two different methods used to create one-dimensional carbon nanostructures, i.e. carbon nanotubes and carbon nanopillars. In the first section, chemical vapor deposition method was used to grow carbon nanotubes (CNTs). Studies examining the effects of methane and hydrogen flow rates on the growth of CNTs were conducted. Results indicated that multi-walled CNTs with metallic properties could be obtained at a methane flow rates as low as 300 cc/min. At higher methane flow rates, i.e. 600-700 cc/min, semiconducting single-walled CNTs and double-walled CNTs were produced. Another phase of this section developed a new and simple CNT growth method using a solid carbon source and indicated polyacrylonitrile and nanosized SiO2 were effective in producing MWCNTs. In the second part, a new nanoimprint technique was developed to enable printing of nanostructures at sub-100nm level using various polymers. This technique inherited its high-resolution feature from traditional nanoimprint lithography, but without the use of pressure. To demonstrate, PAN nanopillar structures were printed and converted to carbon. In another phase of the part, the use of our imprint technique resulted in the creation and conversion of polysilazane nanostructures to ceramic for the first time. The final section of this dissertation is devoted to study the impact of porosity in gas diffusion layers (GDLs) on the performance of fuel cells. In one study, a new technique using SEM images to determine GDL porosity was developed. The difference between SEM calculated porosities and mercury intrusion porosimetry measurements were less than 2%. The second study characterized fuel cell performances using GDLs constructed with additional micro porous layers (MPLs) and treated with different wet proofing treatments (WPT). Results showed that when MPL is added, cell performance decreases. However, the increase in WPT in the MPL improved cell performance.
