Nanostructured Anodic Metal Oxides

Nanostructured Anodic Metal Oxides
Author: Grzegorz D Sulka
Publsiher: Micro and Nano Technologies
Total Pages: 484
Release: 2020-03
ISBN 10: 0128167068
ISBN 13: 9780128167069
Language: EN, FR, DE, ES & NL

Nanostructured Anodic Metal Oxides Book Review:

Nanostructured Anodic Metal Oxides: Synthesis and Applications reviews the current status of fabrication strategies that have been successfully developed to generate nanoporous, nanotubular and nanofibrous anodic oxides on a range of metals. The most recent achievements and innovative strategies for the synthesis of nanoporous aluminum oxide and nanotubular titanium oxide are discussed. However, a special emphasis is placed on the possibility of fabrication of nanostructured oxide layers with different morphologies on other metals, including aluminum titanium, tantalum, tin, zinc, zirconium and copper. In addition, emerging biomedical applications of synthesized materials are discussed in detail. During the past decade, great progress has been made both in the preparation and characterization of various nanomaterials and their functional applications. The anodization of metals has proven to be reliable for the synthesis of nanoporous, nanotubular and nanofibrous metal oxides to produce a desired diameter, density, aspect ratio (length to diameter) of pores/tubes, and internal pore/tube structure.

Nanostructured Anodic Metal Oxides

Nanostructured Anodic Metal Oxides
Author: Grzegorz D. Sulka
Publsiher: Elsevier
Total Pages: 484
Release: 2020-03-27
ISBN 10: 0128168773
ISBN 13: 9780128168776
Language: EN, FR, DE, ES & NL

Nanostructured Anodic Metal Oxides Book Review:

Nanostructured Anodic Metal Oxides: Synthesis and Applications reviews the current status of fabrication strategies that have been successfully developed to generate nanoporous, nanotubular and nanofibrous anodic oxides on a range of metals. The most recent achievements and innovative strategies for the synthesis of nanoporous aluminum oxide and nanotubular titanium oxide are discussed. However, a special emphasis is placed on the possibility of fabrication of nanostructured oxide layers with different morphologies on other metals, including aluminum titanium, tantalum, tin, zinc, zirconium and copper. In addition, emerging biomedical applications of synthesized materials are discussed in detail. During the past decade, great progress has been made both in the preparation and characterization of various nanomaterials and their functional applications. The anodization of metals has proven to be reliable for the synthesis of nanoporous, nanotubular and nanofibrous metal oxides to produce a desired diameter, density, aspect ratio (length to diameter) of pores/tubes, and internal pore/tube structure. Provides an in-depth overview of anodization techniques for a range of metals Explores the emerging applications of anodic metal oxides Explains mechanisms of formation valve metal oxides via anodization

Nanostructured Photocatalyst via Defect Engineering

Nanostructured Photocatalyst via Defect Engineering
Author: Vitaly Gurylev
Publsiher: Springer Nature
Total Pages: 135
Release: 2022
ISBN 10: 3030819116
ISBN 13: 9783030819118
Language: EN, FR, DE, ES & NL

Nanostructured Photocatalyst via Defect Engineering Book Review:

1 Dimensional Metal Oxide Nanostructures

1 Dimensional Metal Oxide Nanostructures
Author: Zainovia Lockman
Publsiher: CRC Press
Total Pages: 331
Release: 2018-12-07
ISBN 10: 1351266713
ISBN 13: 9781351266710
Language: EN, FR, DE, ES & NL

1 Dimensional Metal Oxide Nanostructures Book Review:

1-D metal oxide nanostructures, especially those with semiconducting properties, have attracted much attention in recent years due to their potential and emerging applications, specifically in environment purification and energy devices. For these applications, there have been many efforts to grow 1-D nanostructures in the form of nanotubes, nanorods, and nanowires using processes that conserve energy, are cost effective, and can be scaled up for large-scale production. 1-Dimensional Metal Oxide Nanostructures gathers under one title the most recent development of oxide nanomaterials, especially those fabricated via oxidation process in the nanoscale field. Thermal and anodic oxidation processes are reviewed with an aim to offer an in-depth understanding of mechanisms of 1-D nanostructure formation, their characteristics, and limitations. Other more common methods are also discussed, including sol-gel, hydrothermal, and other templated methods. Important applications of 1-D nanostructures are then presented, focusing on oxides like zinc oxide, titanium oxide, zirconium oxide, copper oxide, and iron oxide. A chapter on carbon nanotubes hybrid with these oxides is also included as well as one on silicon oxide nanowires formation by local anodic oxidation process. Aimed at researchers, academics, and engineers working across the fields of nanotechnology, materials science, chemistry, physics, semiconductors, and environmental and biomedical engineering, this essential reference enables readers to grasp the main concepts of nanomaterials in 1-D: formation technique, characteristics, and uses. It also encourages practical innovations in nanotechnology, especially in curbing pressing global issues related to energy, environment, and security.

Green Nanotechnology

Green Nanotechnology
Author: Marcelo Larramendy,Sonia Soloneski
Publsiher: BoD – Books on Demand
Total Pages: 256
Release: 2016-06-01
ISBN 10: 9535124099
ISBN 13: 9789535124092
Language: EN, FR, DE, ES & NL

Green Nanotechnology Book Review:

This book, Green Nanotechnology - Overview and Further Prospects, is intended to provide an overview and practical examples of the use of nanomaterials in the new scientific challenges of the green nanotechnology world. We aimed to compile information from a diversity of sources into a single volume to give some real examples, extending the concept that green nanotechnology is far from being a scientific conundrum, and instead a real answer to some of the actual problems the whole planet is dealing with.

Heterogeneous Catalysts

Heterogeneous Catalysts
Author: Wey Yang Teoh,Atsushi Urakawa,Yun Hau Ng,Patrick Sit
Publsiher: John Wiley & Sons
Total Pages: 768
Release: 2021-06-08
ISBN 10: 3527344152
ISBN 13: 9783527344154
Language: EN, FR, DE, ES & NL

Heterogeneous Catalysts Book Review:

Presents state-of-the-art knowledge of heterogeneous catalysts including new applications in energy and environmental fields This book focuses on emerging techniques in heterogeneous catalysis, from new methodology for catalysts design and synthesis, surface studies and operando spectroscopies, ab initio techniques, to critical catalytic systems as relevant to energy and the environment. It provides the vision of addressing the foreseeable knowledge gap unfilled by classical knowledge in the field. Heterogeneous Catalysts: Advanced Design, Characterization and Applications begins with an overview on the evolution in catalysts synthesis and introduces readers to facets engineering on catalysts; electrochemical synthesis of nanostructured catalytic thin films; and bandgap engineering of semiconductor photocatalysts. Next, it examines how we are gaining a more precise understanding of catalytic events and materials under working conditions. It covers bridging pressure gap in surface catalytic studies; tomography in catalysts design; and resolving catalyst performance at nanoscale via fluorescence microscopy. Quantum approaches to predicting molecular reactions on catalytic surfaces follows that, along with chapters on Density Functional Theory in heterogeneous catalysis; first principles simulation of electrified interfaces in electrochemistry; and high-throughput computational design of novel catalytic materials. The book also discusses embracing the energy and environmental challenges of the 21st century through heterogeneous catalysis and much more. Presents recent developments in heterogeneous catalysis with emphasis on new fundamentals and emerging techniques Offers a comprehensive look at the important aspects of heterogeneous catalysis Provides an applications-oriented, bottoms-up approach to a high-interest subject that plays a vital role in industry and is widely applied in areas related to energy and environment Heterogeneous Catalysts: Advanced Design, Characterization and Applications is an important book for catalytic chemists, materials scientists, surface chemists, physical chemists, inorganic chemists, chemical engineers, and other professionals working in the chemical industry.

Nanostructured Materials in Electrochemistry

Nanostructured Materials in Electrochemistry
Author: Ali Eftekhari
Publsiher: John Wiley & Sons
Total Pages: 489
Release: 2008-06-25
ISBN 10: 3527621512
ISBN 13: 9783527621514
Language: EN, FR, DE, ES & NL

Nanostructured Materials in Electrochemistry Book Review:

Providing the unique and vital link between the worlds of electrochemistry and nanomaterials, this reference and handbook covers advances in electrochemistry through the nanoscale control of electrode structures, as well as advances in nanotechnology through electrochemical synthesis strategies. It demonstrates how electrochemical methods are of great scientific and commercial interest due to their low cost and high efficiency, and includes the synthesis of nanowires, nanoparticles, nanoporous and layered nanomaterials of various compositions, as well as their applications -- ranging from superior electrode materials to energy storage, biosensors, and electroanalytical devices.

Metal Oxide Nanostructures

Metal Oxide Nanostructures
Author: Daniela Nunes,Ana Pimentel,Lidia Santos,Pedro Barquinha,Luis Pereira,Elvira Fortunato,Rodrigo Martins
Publsiher: Elsevier
Total Pages: 328
Release: 2018-11-01
ISBN 10: 012811505X
ISBN 13: 9780128115053
Language: EN, FR, DE, ES & NL

Metal Oxide Nanostructures Book Review:

Metal Oxide Nanostructures: Synthesis, Properties and Applications covers the theoretical and experimental aspects related to design, synthesis, fabrication, processing, structural, morphological, optical and electronic properties on the topic. In addition, it reviews surface functionalization and hybrid materials, focusing on the advantages of these oxide nanostructures. The book concludes with the current and future prospective applications of these materials. Users will find a complete overview of all the important topics related to oxide nanostructures, from the physics of the materials, to its application. Delves into hybrid structured metal oxides and their promising use in the next generation of electronic devices Includes fundamental chapters on synthesis design and the properties of metal oxide nanostructures Provides an in-depth overview of novel applications, including chromogenics, electronics and energy

Anodic Nanostructures for Solar Cell Applications

Anodic Nanostructures for Solar Cell Applications
Author: Jia Lin
Publsiher: Unknown
Total Pages: 135
Release: 2016
ISBN 10: 1928374650XXX
ISBN 13: OCLC:1154249919
Language: EN, FR, DE, ES & NL

Anodic Nanostructures for Solar Cell Applications Book Review:

As a versatile, straightforward, and cost-effective strategy for the synthesis of self-organized nanomaterials, electrochemical anodization is nowadays frequently used to synthesize anodic metal oxide nanostructures for various solar cell applications. This chapter mainly discusses the synthesis of various anodic TiO2 nanostructures on foils and as membranes or powders, and their potential use as the photoanode materials based on foils, transparent conductive oxide substrates, and flexible substrates in dye-sensitized solar cell applications, acting as dye-loading frames, light-harvesting enhancement assembly, and electron transport medium. Through the control and modulation of the electrical and chemical parameters of electrochemical anodization process, such as applied voltages, currents, bath temperatures, electrolyte composition, or post-treatments, anodic nanostructures with controllable structures and geometries and unique optical, electronic, and photoelectric properties in solar cell applications can be obtained. Compared with other types of nanostructures, there are several major advantages for anodic nanostructures to be used in solar cells. They are (1) optimized solar cell configuration to achieve efficient light utilization; (2) easy fabrication of large size nanostructures to enhance light scattering; (3) precise modulation of the electrochemical processes to realize periodic nanostructured geometry with excellent optical properties; (4) unidirectional electron transport pathways with suppressed charge recombination; and (5) large surface areas by modification of nanostructures. Due to the simple fabrication processes and unique properties, the anodic nanostructures will have a fascinating future to boost the solar cell performances.

Advanced Coating Materials

Advanced Coating Materials
Author: Liang Li,Qing Yang
Publsiher: John Wiley & Sons
Total Pages: 546
Release: 2018-11-15
ISBN 10: 1119407648
ISBN 13: 9781119407645
Language: EN, FR, DE, ES & NL

Advanced Coating Materials Book Review:

This book covers the recent advances in coating materials and their novel applications at the cross-section of advanced materials both current and next-generation. Advanced Coatings Materials contains chapters covering the latest research on polymers, carbon resins, and high-temperature materials used for coatings, adhesives, and varnishes today. Concise chapters describe the development, chemical and physical properties, synthesis and polymerization, commercial uses, and other characteristics for each raw material and coating detailed. A comprehensive, yet practical source of reference, this book provides an excellent foundation for comparing the properties and performance of coatings and selecting the most suitable materials based on specific service needs and environmental factors.

Multifunctional Nanostructured Metal Oxides for Energy Harvesting and Storage Devices

Multifunctional Nanostructured Metal Oxides for Energy Harvesting and Storage Devices
Author: Vijay B. Pawade,Paresh H. Salame,Bharat Apparao Bhanvase
Publsiher: CRC Press
Total Pages: 328
Release: 2020-05-21
ISBN 10: 1000073203
ISBN 13: 9781000073201
Language: EN, FR, DE, ES & NL

Multifunctional Nanostructured Metal Oxides for Energy Harvesting and Storage Devices Book Review:

Metal oxide nanoparticles exhibit potential applications in energy and environmental fields, such as solar cells, fuel cells, hydrogen energy, and energy storage devices. This book covers all points from synthesis, properties, and applications of transition metal oxide nanoparticle materials in energy storage and conversion devices. Aimed at graduate-level students and researchers associated with the energy and environment sector, this book addresses the application of nontoxic and environmentally friendly metal oxide materials for a clean environment and deals with synthesis properties and application metal oxides materials for energy conversion, energy storage, and hydrogen generation.

Electrochemistry in Molecular and Microscopic Dimensions

Electrochemistry in Molecular and Microscopic Dimensions
Author: International Society of Electrochemistry. Meeting
Publsiher: Elsevier
Total Pages: 560
Release: 2003
ISBN 10: 9780444515599
ISBN 13: 0444515593
Language: EN, FR, DE, ES & NL

Electrochemistry in Molecular and Microscopic Dimensions Book Review:

This book is a hard bound edition of a special issue (vol. 48/20-22) of the journal Electrochimica Acta. It summarizes the highlights of the 53rd Annual meeting of the International Society of Electrochemistry and Annual meeting of the GDCh-Fachgruppe Angewandte Elektrochemie. The theme of the conference was Electrochemistry in Molecular and Microscopic dimensions and was based on the role of electrochemistry in the miniaturization of chemical and physical methods. Topics covered are : - development of electrochemistry with microscopic and molecular resolution; - initiation of advances in Electrochemical Microsystem Technologies EMT, and micro/nano-electronics; - development of Electrochemical Materials Science for nanomaterials; - enhancement of miniaturization and sensitivity of electroanalysis, and; - the bridge from electrochemistry to biology and medicine of microscopic and molecular understanding. - Summarizes the highlights of two major electrochemistry meetings. - It includes research papers on the electrochemical processes in micro- and nanotechnology. - Highlights developments and advances in electrochemistry.

Metal Oxide Nanostructures as Gas Sensing Devices

Metal Oxide Nanostructures as Gas Sensing Devices
Author: G. Eranna
Publsiher: CRC Press
Total Pages: 336
Release: 2011-12-19
ISBN 10: 1439863407
ISBN 13: 9781439863404
Language: EN, FR, DE, ES & NL

Metal Oxide Nanostructures as Gas Sensing Devices Book Review:

Metal Oxide Nanostructures as Gas Sensing Devices explores the development of an integrated micro gas sensor that is based on advanced metal oxide nanostructures and is compatible with modern semiconductor fabrication technology. This sensor can then be used to create a compact, low-power, handheld device for analyzing air ambience. The book first covers current gas sensing tools and discusses the necessity for miniaturized sensors. It then focuses on the materials, devices, and techniques used for gas sensing applications, such as resistance and capacitance variations. The author addresses the issues of sensitivity, concentration, and temperature dependency as well as the response and recovery times crucial for sensors. He also presents techniques for synthesizing different metal oxides, particularly those with nanodimensional structures. The text goes on to highlight the gas sensing properties of many nanostructured metal oxides, from aluminum and cerium to iron and titanium to zinc and zirconium. The final chapters deal with existing and future devices that are based on nanostructures. Miniaturized systems that analyze air ambience need sensors capable of identifying different gaseous species. Exploring state-of-the-art gas sensing devices, this book shows how nanostructured metal oxides are ideally suited for use as gas sensing elements.

Electrochemically Engineering of Nanoporous Materials

Electrochemically Engineering of Nanoporous Materials
Author: Abel Santos
Publsiher: MDPI
Total Pages: 158
Release: 2018-10-10
ISBN 10: 3038972681
ISBN 13: 9783038972686
Language: EN, FR, DE, ES & NL

Electrochemically Engineering of Nanoporous Materials Book Review:

This book is a printed edition of the Special Issue "Electrochemically Engineering of Nanoporous Materials" that was published in Nanomaterials

Porous Anodic Aluminum Oxide Scaffolds Formation Mechanisms and Applications

Porous Anodic Aluminum Oxide Scaffolds   Formation Mechanisms and Applications
Author: Jihun Oh
Publsiher: Unknown
Total Pages: 161
Release: 2010
ISBN 10: 1928374650XXX
ISBN 13: OCLC:668428538
Language: EN, FR, DE, ES & NL

Porous Anodic Aluminum Oxide Scaffolds Formation Mechanisms and Applications Book Review:

Nanoporous anodic aluminium oxide (AAO) can be created with pores that self-assemble into ordered configurations. Nanostructured metal oxides have proven to be very useful as scaffolds for growth of nanowires and nanotubes with tunable diameters and with tight diameter distributions. For 50 years, field-assisted dissolution of the oxide has been cited as the mechanism that leads to pore formation in alumina, and by analogy, porous anodic TiO2 and other functional metal oxides. We show that field-assisted dissolution models are consistent with the observed dependence of the Al2O3 dissolution rate on the electric field, as well as the existence of a critical field for pore initiation. However, we further show that the well-known ordered porous structure, which has a significantly different length scale, does not result from a field-induced instability, but is instead the result of a strain-induced instability with forced plastic deformation and flow of the oxide during further anodization. We demonstrate that these pore generation mechanisms can be controlled independently, even when they co-exist, by controlling the electric field across the oxide as well as the anodization conditions. We also show that mechanical confinement results in a dendritic pore structure. Through interpretation of these results we develop a generalized mechanism for ordered pore formation in AAO in analogy with cellular solidification. In addition, we report on abnormal behavior in anodic oxidation of Al in mechanically confined structures for formation of horizontal nanoporous anodic alumina oxide, H-AAO. Instead of smooth pore walls, periodic dendrite inner pore structures form, the growth rate is suppressed to 5 % of its value during bulk anodization under the same conditions, and a steady-state is never reached. These anomalies associated with formation of H-AAO originate from suppressed volume expansion and plastic flow of Al2O3 confined by the SiO2 hard mask. By determining new anodization conditions leading to zero volume expansion, dendritic H-AAO can be avoided and kinetic retardation can be minimized. A new method for perforation of the AAO barrier layer has been developed, based on anodization of Al/W bilayer films on substrates. When Al/W bilayer films are anodized and pores approach the Al/W interface, tungsten oxide forms and penetrates the alumina barrier oxide, in part, due to enhanced plasticity of the alumina layer. By selectively etching the tungsten oxide, the barrier oxide can be removed and the base of the pores opened, without etching of the AAO. Finally, we further refined the selective barrier perforation process using the W interlayer to develop a methodology for fabrication of through-pore AAO scaffolds on any conducting substrate (AS) by anodizing an Al/W/AS tri-layer. Structural and kinetic study of the WO3 extrusion revealed that the anodization of W consumes a fixed thickness of the W layer in acidic electrolytes under specific anodization conditions. Based on this study, the optimum thickness of the W interlayer in the Al/W/Au tri-layer was measured for various anodization conditions. Through-pore AAOs were fabricated on Au layers with exposure of the surface at the base of the pores, using the optimum W thickness without a violent O2 evolution reaction and without changing the pore diameters. With scaffolds made using this methodology, vertically-aligned free-standing Au and Pt nanowires with diameters ranging from about 12 nm to about 120 nm were grown by electrodeposition on a gold substrate.

Heterogeneous Catalysts

Heterogeneous Catalysts
Author: Wey Yang Teoh,Atsushi Urakawa,Yun Hau Ng,Patrick Sit
Publsiher: John Wiley & Sons
Total Pages: 768
Release: 2021-02-23
ISBN 10: 352781356X
ISBN 13: 9783527813568
Language: EN, FR, DE, ES & NL

Heterogeneous Catalysts Book Review:

Presents state-of-the-art knowledge of heterogeneous catalysts including new applications in energy and environmental fields This book focuses on emerging techniques in heterogeneous catalysis, from new methodology for catalysts design and synthesis, surface studies and operando spectroscopies, ab initio techniques, to critical catalytic systems as relevant to energy and the environment. It provides the vision of addressing the foreseeable knowledge gap unfilled by classical knowledge in the field. Heterogeneous Catalysts: Advanced Design, Characterization and Applications begins with an overview on the evolution in catalysts synthesis and introduces readers to facets engineering on catalysts; electrochemical synthesis of nanostructured catalytic thin films; and bandgap engineering of semiconductor photocatalysts. Next, it examines how we are gaining a more precise understanding of catalytic events and materials under working conditions. It covers bridging pressure gap in surface catalytic studies; tomography in catalysts design; and resolving catalyst performance at nanoscale via fluorescence microscopy. Quantum approaches to predicting molecular reactions on catalytic surfaces follows that, along with chapters on Density Functional Theory in heterogeneous catalysis; first principles simulation of electrified interfaces in electrochemistry; and high-throughput computational design of novel catalytic materials. The book also discusses embracing the energy and environmental challenges of the 21st century through heterogeneous catalysis and much more. Presents recent developments in heterogeneous catalysis with emphasis on new fundamentals and emerging techniques Offers a comprehensive look at the important aspects of heterogeneous catalysis Provides an applications-oriented, bottoms-up approach to a high-interest subject that plays a vital role in industry and is widely applied in areas related to energy and environment Heterogeneous Catalysts: Advanced Design, Characterization and Applications is an important book for catalytic chemists, materials scientists, surface chemists, physical chemists, inorganic chemists, chemical engineers, and other professionals working in the chemical industry.

Semiconductors Metal Oxides and Composites Metallization and Electrodeposition of Thin Films and Nanostructures

Semiconductors  Metal Oxides  and Composites  Metallization and Electrodeposition of Thin Films and Nanostructures
Author: G. Oskam
Publsiher: The Electrochemical Society
Total Pages: 222
Release: 2010-02
ISBN 10: 156677800X
ISBN 13: 9781566778008
Language: EN, FR, DE, ES & NL

Semiconductors Metal Oxides and Composites Metallization and Electrodeposition of Thin Films and Nanostructures Book Review:

This symposium provided a forum for current work on the electrodeposition and characterization of functional coatings and nanostructures. Central issues include the control of size and architecture and the ample choices and demands of substrate and deposited materials. The focus materials of this symposium were semiconductors, oxides and composites with e.g. ceramic nanoparticles or nanotubes.

Nanostructured Metal Oxide Electrode Materials for Water Purification

Nanostructured Metal Oxide Electrode Materials for Water Purification
Author: Onoyivwe Monday Ama,Suprakas Sinha Ray
Publsiher: Springer Nature
Total Pages: 193
Release: 2020-04-07
ISBN 10: 3030433463
ISBN 13: 9783030433468
Language: EN, FR, DE, ES & NL

Nanostructured Metal Oxide Electrode Materials for Water Purification Book Review:

This book reports on the development of nanostructured metal-oxide-based electrode materials for use in water purification. The removal of organic pollutants and heavy metals from wastewater is a growing environmental and societal priority. This book thus focuses primarily on new techniques to modify the nanostructural properties of various solvent-electrolyte combinations to address these issues. Water treatment is becoming more and more challenging due to the ever increasing complexity of the pollutants present, requiring alternative and complementary approaches toward the removal of toxic chemicals, heavy metals and micro-organisms, to name a few. This contributed volume cuts across the fields of electrochemistry, water science, materials science, and nanotechnology, while presenting up-to-date experimental results on the properties and synthesis of metal-oxide electrode materials, as well as their application to areas such as biosensing and photochemical removal of organic wastewater pollutants. Featuring an introductory chapter on electrochemical cells, this book is well positioned to acquaint interdisciplinary researchers to the field, while providing topical coverage of the latest techniques and methodology. It is ideal for students and research professionals in water science, materials science, and chemical and civil engineering.

Nanostructure of Transition Metal and Metal Oxide for Electrocatalysis

Nanostructure of Transition Metal and Metal Oxide for Electrocatalysis
Author: Yanjuan Gu
Publsiher: Open Dissertation Press
Total Pages: 135
Release: 2017-01-27
ISBN 10: 9781361427170
ISBN 13: 1361427175
Language: EN, FR, DE, ES & NL

Nanostructure of Transition Metal and Metal Oxide for Electrocatalysis Book Review:

This dissertation, "Nanostructure of Transition Metal and Metal Oxide for Electrocatalysis" by Yanjuan, Gu, 谷艳娟, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled NANOSTRUCTURE OF TRANSITION METAL AND METAL OXIDE FOR ELECTROCATALYSIS Submitted by Gu Yan Juan for the degree of Doctor of Philosophy at The University of Hong Kong in August 2006 Pd, Pt, and Ru nanoparticles that were uniformly dispersed on multi-walled carbon nanotubes (MWNTs) were synthesized by vacuum pyrolysis using metal acetylacetonate as metal precursor, and the nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X- ray diffraction (XRD). The size and distribution of the nanoparticles were strongly affected by the reaction time, temperature, and the initial mass ratio of the metal precursors to MWNTs. The higher temperature, the smaller Pd nanoparticles were formed at the range of 250 to 500 C. The average size of the Pd nanoparticles increased with the increase in mass ratio of the metal precursors to MWNTs. The particle size of Pt and Ru showed little change with the change in mass ratio. Pt and Ru nanoparticles had the mean diameters of 3.00.6 and 2.50.4 nm when the mass ratio of Pt(acac) and Ru(acac) to 2 3 MWNTs was both 2:1 at 500 C. The electrocatalytic activity of Pt/MWNTs and PtRu/MWNTs was investigated at room temperature by cyclic voltammetry and chronoamperometry. All of the electrochemical results showed that the PtRu/MWNTs catalyst exhibit high activity for methanol oxidation that resulted from the high surface area of carbon nanotubes and the platinum/ruthenium nanoparticles. Compared with Pt/MWNTs, the onset potential is much lower and the ratio of forward anodic peak current to reverse anodic peak current is much higher for methanol oxidation. Pt Ru /MWNTs displayed the best electrocatalytic 45 55 activities among all carbon nanotubes supported Pt and PtRu catalysts. Hyperbranched RuO nanostructures can be formed through the oxidation of Ru nanoparticles at relatively low temperatures in air, which is a very simple and low cost method. The morphology of the RuO nanostructure is closely associated with the dispersivity of the Ru nanoparticles on the MWNTs. Cu, Pt and Pd nanoparticles are very effective catalysts in the formation of RuO hyperbranched nanostructures. The electrochemical studies of these nanorods demonstrated that they display characteristic properties of RuO (110) surface. The successful attachment of Pt nanoparticles to RuO surface through a simple, two-step chemically controlled procedure is reported. The effect of the single crystal structure of RuO nanorods on the electrocatalytic activity of Pt nanoparticles was investigated, showing that the presence of the RuO nanorods greatly increases the electrochemical activity of electrodes toward methanol oxidation, not only increasing the current density but also shifting the onset potential of methanol electrooxidation to over 200 mV lower than that on the Pt nanoparticle electrode. The results described here also demonstrate the ability of metal oxide nanorods to serve as a conductive support for fuel cell applications. DOI: 10.5353/th_b3777439 Subjects: Electrocatalysis Transition metals Nanoparticles Nanostructured materials Methanol - Oxidation

Nanostructured Metal Oxides

Nanostructured Metal Oxides
Author: Enrico Traversa
Publsiher: The Electrochemical Society
Total Pages: 240
Release: 2006-01-01
ISBN 10: 1566775094
ISBN 13: 9781566775090
Language: EN, FR, DE, ES & NL

Nanostructured Metal Oxides Book Review:

The use of metal oxides in nanostructured form, made possible by recent advances in their synthesis, allow the exploitation of unique physical and chemical properties of materials. This issue presents te latest advances in the controlled syntheseis and processing of nanostructured oxides, and the design, fabrication, and performance of devices that utilize them. The emphasis will be on the beneficial effects of using nanostructured materials in enviromentally-friendly applications.