Download or read book Synthesis of Ordered Mesoporous Materials Via Microwave Processing and Highly Heteroatom Doped Ordered Mesoporous Carbons for Energy Storage written by Yanfeng Xia and published by . This book was released on 2018 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ordered mesoporous materials, with pore diameter between 2 nm to 50 nm, have drawn researchers interests due to their superb properties including large surface area, uniform and adjustable pore architecture and good mechanical property, which allow a variety of different applications of the mesoporous materials, including catalysis, separation, purification, sensing and energy storage. Researchers have also reported different functionalization strategies of these mesoporous materials to improve the properties, such as improving electrochemical property by heteroatom doping of mesoporous carbon. One generalized synthetic strategy to synthesize ordered mesoporous materials is soft templating method. The functionalization of these mesoporous materials, such as heteroatom doping, can sometimes to lead ordered porous structure collapse, which is usually due to structure deformation during high temperature treatment. For instance, it is challenging to synthesize ordered mesoporous metal oxide with high crystalline pore wall with soft-templating method, as the growth of the crystals can deform the ordered porous structure. Meanwhile, it is difficult to synthesize ordered mesoporous carbon with high doping level (>10 at%) via soft-templating strategy as well, since the rapid doping reaction at high temperature can lead to ordered structure collapse due to the high vapor pressure generated by doping reactions. Here, we demonstrate several facile synthetic routes to fabricate highly crystalline ordered mesoporous metal oxide and heteroatom doped ordered mesoporous carbon. The application of the nitrogen doped mesoporous carbons in energy storage has also been discussed in this dissertation.Ordered mesoporous manganese oxide has been reported to be useful in energy storage due to its good electrochemical property, as the transition metal manganese has half-filled 3d orbital, which allows it to donate or accept electrons. However, synthesizing ordered mesoporous manganese oxide with high crystallinity with soft-templating strategy is challenging, as the crystal formation during thermal treatment can deform the ordered porous structure. In this dissertation, the synthesis of ordered mesoporous crystalline manganese oxide films is achieved by microwave-assisted processing to convert manganese carbonate precursor to the oxide, remove the polymeric template and crystallize the Mn3O4, all within 1 min. The microwave heating in this case is primarily induced by the microwave cross-section of the substrate (silicon wafer), together with the absorption of microwaves by manganese oxide to provide local energy, which can provide energy for nucleation/crystallization. Conversely, heating manganese carbonate in a muffle furnace at an analogous surface temperature leads to nanostructure collapse with low crystallinity. Apart from the synthesis of highly crystalline ordered mesoporous metal oxide, we also demonstrate the functionalization of ordered mesoporous carbon via heteroatom doping. Doped carbons can exhibit enhanced electronic, electrochemical and mechanical properties compared with un-doped carbons. These properties enable their use in applications, such as photovoltaics, catalysis and energy storage. For these applications, nano porosity and high heteroatom doping are generally desirable due to large surface area provided by nanoporous structure and improved properties contributed by heteroatom doping. However, it is challenging to achieve high content of heteroatoms doped carbons as well as maintaining the nanoporous structure. One common method of doping is to use heteroatom containing polymer precursors and carbonizing to synthesize doped carbon, where heteroatom content is limited by the number density of heteroatoms in the precursors. Additionally, during calcination, the nanoporous structure can collapse due to the contraction of pores. In this dissertation, a generalized synthetic strategy for highly doped ordered mesoporous carbons is reported. High concentrations of heteroatom doping in ordered mesoporous carbon is achieved by infiltration of molten dopants into silica reinforced mesoporous crosslinked polymer (phenolic resol) bi-continuous framework and subsequent carbonization. This method is demonstrated to generate ordered mesoporous carbons with high heteroatom content (> 10%) for a wide variety of elements including nitrogen, boron, sulfur and phosphorus, with ordered structure preserved. With the generalized synthetic route, nitrogen doped multi-shell hollow carbon are fabricated as a matrix material for Lithium-sulfur batteries. The hierarchical hollow structure and chemical decoration (heteroatom doping) of carbon framework can help to suppress polysulfide shuttling, while the macropore provides large pore volume to increase sulfur loading. The nitrogen doped sample shows better cycle stability compared with un-doped sample. Given that this hollow structure with a macropore can increase sulfur loading, the specific capacity is much lower compared with other cases where the pores are much smaller because of the low conductivity of sulfur.In addition, we also systematically investigate how nitrogen doping influences the rate that molten sulfur can infiltrate and the overall extent of pore filling of highly ordered mesoporous doped carbons via in-situ small angle x-ray scattering (SAXS). Nitrogen doping introduces polar bonds to the carbon framework, which can slow down the diffusion of nonpolar sulfur molecules into porous carbon. These in-situ SAXS measurements provide insights about kinetics information for diffusion of sulfur into mesopores and how the surface chemistry of nitrogen doped carbon can significantly hinder the infiltration of the mesopores by sulfur. In summary, this dissertation focuses on the functionalization of ordered mesoporous material without losing the ordered structure, as well as the application of nitrogen doped carbon in energy storage.
Download or read book Mesoporous Materials for Advanced Energy Storage and Conversion Technologies written by San Ping Jiang and published by CRC Press. This book was released on 2017-05-25 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovation through specific and rational design and functionalization has led to the development of a wide range of mesoporous materials with varying morphologies (hexagonal, cubic, rod-like), structures (silicates, carbons, metal oxides), and unique functionalities (doping, acid functionalization) that currently makes this field one of the most exciting in materials science and energy applications. This book focuses primarily on the rapid progress in their application in energy conversion and storage technologies, including supercapacitor, Li-ion battery, fuel cells, solar cells, and photocatalysis (water splitting) and will serve as a valuable reference for researchers in the field
Download or read book Functional Mesoporous Carbon Based Film Devices for Energy Systems written by Biao Kong and published by Springer Nature. This book was released on 2024-01-09 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the synthesis of functional mesoporous carbon-based films and their applications in energy systems. In the last decades, the consumption of fossil fuels has led to many problems such as the energy crisis and climate change. The rapidly increasing energy demands and environmental issues have attracted lots of attention to develop new functional materials for sustainable energy technology. Mesoporous carbon-based films show unique properties and have been regarded as a promising material applied in highly efficient energy storage and conversion systems. Interfacial assembly strategies are usually employed to construct such film devices. In this book, recent developments in synthesis of mesoporous carbon-based film devices through interfacial assembly strategies are illustrated. Additionally, the applications of mesoporous carbon-based film devices for electrochemical energy systems including batteries and electrocatalysis are introduced to demonstrate their potential, as well as describing the mechanisms to enhance the performance of these systems. Finally, some challenges and future outlooks are presented to inspire better development and contributions to this field in coming years. Given its scope, this book appeals to undergraduate students, graduate students, engineers, and researchers involved in related fields.
Download or read book Horizons in Materials written by Nicola Maria Pugno and published by Frontiers Media SA. This book was released on 2022-08-23 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Frontiers in Materials Editorial Office team are delighted to present the “Horizons in Materials” article collection, showcasing high-impact, authoritative, and accessible Review articles covering important topics at the forefront of the materials science and engineering field. All contributing authors were nominated by the Chief Editors and Editorial Office in recognition of their prominence and influence in their respective fields. The cutting-edge work presented in this article collection highlights the diversity of research performed across the entire breadth of the materials science and engineering field and reflects on the latest advances in theory, experiment, and methodology with applications to compelling problems. This Editorial features the corresponding author(s) of each paper published within this important collection, ordered by section alphabetically, highlighting them as the great researchers of the future. The Frontiers in Materials Chief Editors and Editorial Office team would like to thank each researcher who contributed their work to this collection. We are excited to see each article gain the deserved visibility and traction within the wider community, ensuring the collection’s truly global impact and success. Emily Young Journal Manager
Download or read book Ordered Mesoporous Materials written by Dongyuan Zhao and published by John Wiley & Sons. This book was released on 2012-11-28 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mesoporous materials are a class of molecules with a large and uniform pore size, highly regular nanopores, and a large surface area. This book is devoted to all aspects and types of these materials and describes, in an in-depth and systematic manner, the step-by-step synthesis and its mechanism, as well as the characterization, morphology control, hybridization, and applications, of mesoporous molecular sieves. In so doing, it covers silicates, metal-doped silicates, nonsilicates, and organic-inorganic hybrids. Although the emphasis is on synthesis, the expert authors also discuss characterization and applications, ranging from catalysis and biochemistry to optics and the use of these materials as templates for nanomaterial synthesis. Both the fundamentals and the latest research results are covered, ensuring that this monograph serves as a reference for researchers in and newcomers to the field.
Download or read book Synthesis and Characterisation of Ordered Mesoporous Materials written by Troy Allen Dougherty and published by . This book was released on 2010 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared and Raman Spectroscopy written by Peter Larkin and published by Elsevier. This book was released on 2017-11-13 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared and Raman Spectroscopy, Principles and Spectral Interpretation, Second Edition provides a solid introduction to vibrational spectroscopy with an emphasis on developing critical interpretation skills. This book fully integrates the use of both IR and Raman spectroscopy as spectral interpretation tools, enabling the user to utilize the strength of both techniques while also recognizing their weaknesses. This second edition more than doubles the amount of interpreted IR and Raman spectra standards and spectral unknowns. The chapter on characteristic group frequencies is expanded to include increased discussions of sulphur and phosphorus organics, aromatic and heteroaromatics as well as inorganic compounds. New topics include a discussion of crystal lattice vibrations (low frequency/THz), confocal Raman microscopy, spatial resolution in IR and Raman microscopy, as well as criteria for selecting Raman excitation wavelengths. These additions accommodate the growing use of vibrational spectroscopy for process analytical monitoring, nanomaterial investigations, and structural and identity determinations to an increasing user base in both industry and academia. Integrates discussion of IR and Raman spectra Pairs generalized IR and Raman spectra of functional groups with tables and text Includes over 150 fully interpreted, high quality IR and Raman reference spectra Contains fifty-four unknown IR and Raman spectra, with a corresponding answer key
Download or read book Nanostructured Materials for Energy Storage and Conversion written by Xiulei Ji and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mesoporous Materials for Advanced Energy Storage and Conversion Technologies written by Jian Liu and published by CRC Press. This book was released on 2021-03-31 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovation through specific and rational design and functionalization has led to the development of a wide range of mesoporous materials with varying morphologies (hexagonal, cubic, rod-like), structures (silicates, carbons, metal oxides), and unique functionalities (doping, acid functionalization) that currently makes this field one of the most exciting in materials science and energy applications. This book focuses primarily on the rapid progress in their application in energy conversion and storage technologies, including supercapacitor, Li-ion battery, fuel cells, solar cells, and photocatalysis (water splitting) and will serve as a valuable reference for researchers in the field
Download or read book Design and Synthesis of Crystalline Metal Oxide Sulfide Based Mesoporous Materials written by Lei Jin and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mesoporous materials process many unique properties, such as high surface area and large pore volume, which are important in the applications of catalysis and energy storage. In these applications, mesoporous materials with controllable porosity and crystallinity are critical. However, the synthesis of mesoporous materials with crystallinity is challenging using traditional methods due to the disruption of mesoporosity at high temperatures. Therefore, a novel synthetic strategy is needed. In this thesis, the design and general synthesis of mesoporous materials with controllable mesoporosity and crystallinity were reported. The mesoporous materials include oxides, sulfides, and metal oxides-based hybrid materials. Furthermore, their porosity-correlated properties and applications in catalysis and energy storage devices are discussed in each chapter. The first chapter involves the synthesis of mesoporous complex oxides with high crystallinity by colloidal-amphiphile-micelle (CAM) templates. Organosilane-containing CAM templates can convert into thermally stable silica that prevents the overgrowth of crystalline grains and the collapse of the mesoporosity of oxides at high temperatures. This method is general and applicable to various complex oxides with mesoporosity and crystallinity. Furthermore, the antiferromagnetic ordering temperature of mesoporous cobalt titanate is studied to understand the correlation between mesoscale porosity and electromagnetic properties. Following that, the thermally stable titania confined metal nanoparticles (Au, Pd, and PdAu) are designed and synthesized by the co-assembly of polymer-tethered metal nanoparticles and CAM templates. On one hand, the high-temperature synthesis of mesoporous Au and TiO2 hybrids has been developed. Well-defined nanostructures of Au and porous structures of TiO2 can be retained while improving the crystallinity of TiO2 and its strong metal-support interactions (SMSIs). Under thermal annealing, oxidative SMSIs found in Au-TiO2 show great impact on their photocatalytic activity. On the other hand, using bimetallic PdAu, the impact of oxide support has been studied in term of their hydrogenation activity and selectivity. The last chapter describes the synthesis of mesoporous metal sulfides through a facile solid-state synthesis. Metal sulfides, such as cobalt sulfides, nickel sulfides, and their binary sulfides, are synthesized. The sulfides are used as electrode materials in supercapacitors. The mesoporosity and the synergistic effect of binary sulfides show great impact on the supercapacitive performance.
- Author : 杨纯臻
- Publisher :
- Release : 2017-01-26
- ISBN : 9781361005330
- Pages : pages
Metal Metal Oxide Nanoparticles Supported on Nanostructured Carbons for Electrochemical Applications
Download or read book Metal Metal Oxide Nanoparticles Supported on Nanostructured Carbons for Electrochemical Applications written by 杨纯臻 and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Metal/metal oxide nanoparticles supported on nanostructured carbons for electrochemical applications" by 杨纯臻, Chunzhen, Yang, 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: Among various electrochemical devices that have been developed for energy storage and conversion, electric double layer capacitors (EDLCs) and direct methanol fuel cells (DMFC) have received much research attention. Nanostructured carbon materials have been playing an important role in the development of these devices, due to such characteristics as good electrical conductivity, high chemical stability, high surface area and large pore volumes and etc. In an EDLC, nanostructured carbon electrodes, possessing pores of varied length scales, can deliver electric energy at high current loadings. This kind of pore structure also benefits the deposition of metal catalysts and the transport of reactants and products in the methanol oxidation reaction. In order to systematically study the structural effects on the electrochemical capacitance and ionic transport, a series of three-dimensional hierarchical carbons with hollow core-mesoporous shell (HCMS) structure were template-synthesized. Periodically ordered macroscopic hollow cores of 330 nm in diameter were surrounded by a mesoporous shell containing uniform pores of 3.9 nm. The shell thickness was stepwise increased from 0, 25, 50 to 100 nm. The HCMS structure was modeled by a 5-level transmission line model to study the capacitance contribution from the pores at different length scale. Results revealed that the HCMS carbon with thicker mesoporous shells can provide high capacitance, while thinner shells could deliver high power output. A series of HCMS carbon sphere supported Pt nanoparticles were synthesized via the "Carbonization over Protected and Dispersed Metal" (CPDM) method. Contrary to the conventional "polyol" synthetic method, whereas most of Pt nanoparticles were deposited on the external surface of carbon spheres; the Pt nanoparticles synthesized via the CPDM method were found encapsulated in the mesoporous carbon shells and highly dispersed throughout the carbon texture. "Accelerated stress tests‟ (ASTs) were conducted to investigate the nanopores confinement effect toward the electrochemical stability of these Pt catalysts. Results revealed that (1) the nanopores confined Pt nanoparticles on HCMS carbon spheres exhibited a stable electrochemical active surface area (ECSA) and catalytic activity; and (2) thick mesoporous carbon shells could provide better protection over the Pt nanoparticles. This "CPDM" method was further extended to synthesize highly alloyed PtRu nanoparticles supported electrocatalysts. It is expected that this CPDM method can also be applied to synthesize other metal/metal oxide supported catalysts with stable electrochemical performance. WO3 has been demonstrated as a promsing co-catalyst for Pt in the methanol oxidation reaction (MOR). The synthesis of Pt-WO3/C catalyst with well-controlled nanoparticle size (2.5 nm) and composition was achieved via a microwave-assisted water-oil microemulsion reaction. Hydrogen adsorption, CO-stripping and Cu- stripping methods were used to estimate the ECSA of Pt in the Pt-WO3/C catalysts. Among these, Cu-stripping method was relatively more reliable due to the overlapping involvement of the WO3 component in the other methods. The methanol oxidation measurement shows that a 1:1 Pt: W ratio catalyst exhibits the highest Pt-mass current density of 271 mA mg-1-Pt, 1.4 times higher than that of commercial E-TEK catalyst.
Download or read book The Preparation of Ordered Mesoporous Materials written by Sun-Young Park and published by . This book was released on 2008 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on the effect of different experimental conditions including conventional hydrothermal synthesis and supercritical carbon dioxide (SCCO2) methods on materials characteristics in terms of particle morphology and pore geometry. Three types of mesoporous silicas were investigated by different synthesis methods, that is, MCM- 41, SBA-15 and -16. These materials were used as a target molecule due to its high volatility and strong antimicrobial characteristics.
Download or read book Synthesis and Characterization of Ordered Mesoporous Transition Metal Oxides and Nitrides written by Spencer William Robbins and published by . This book was released on 2015 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling the structure of inorganic materials on the mesoscale (2-50 nm) is desirable for many applications and can influence the materials' properties and performance in devices. Amphiphilic block copolymers (BCPs) have been used extensively to structure-direct transition metal oxides, controlling their mesoscale morphology. By selectively incorporating metal oxide precursors into one block of the BCP and removing the BCP through thermal decomposition, ordered mesoporous metal oxides with well-defined mesoscale morphologies can be achieved that are interesting, e.g. for energy conversion and storage applications. This dissertation reports on the amphiphilic block terpolymer poly(isoprene)-blockpoly(styrene)-block-poly(ethylene oxide) used in combination with sol-gel metal oxide precursors to generate ordered three-dimensionally (3D) mesoporous metal oxides. 3D cocontinuous cubic network structures such as the alternating gyroid are particularly interesting for energy applications due to their chirality, co-continuity, and high porosity. In particular, the high porosity and mesoscale dimensions can facilitate rapid diffusion of gases/liquids, but limit solid state diffusion lengths in the inorganic structure during chemical conversions of the oxides, e.g. nitriding. Freestanding gyroidal mesoporous metal oxides can be further processed into gyroidal mesoporous metal nitrides by heating under flowing ammonia gas. Transition metal nitrides are of interest due to their electrical conductivity and electrochemical stability. The development of a synthesis for 3D ordered mesoporous nitrides opens paths for studying the effects of welldefined block copolymer mesostructures on superconductivity, an exciting new field.
Download or read book Synthesis and Characterization of Mesoporous Materials for Energy Storage written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercapacitors written by Francois Beguin and published by John Wiley & Sons. This book was released on 2013-04-02 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercapacitors are a relatively new energy storage system that provides higher energy density than dielectric capacitors and higher power density than batteries. They are particularly suited to applications that require energy pulses during short periods of time, e.g., seconds or tens of seconds. They are recommended for automobiles, tramways, buses, cranes, fork-lifts, wind turbines, electricity load leveling in stationary and transportation systems, etc. Despite the technological maturity of supercapacitors, there is a lack of comprehensive literature on the topic. Many high performance materials have been developed and new scientific concepts have been introduced. Taking into account the commercial interest in these systems and the new scientific and technological developments now is the ideal time to publish this book, capturing all this new knowledge. The book starts by giving an introduction to the general principles of electrochemistry, the properties of electrochemical capacitors, and electrochemical characterization techniques. Electrical double layer capacitors and pseudocapacitors are then discussed, followed by the various electrolyte systems. Modelling, manufacture of industrial capacitors, constraints, testing, and reliability as well as applications are also covered. 'Supercapacitors - Materials, Systems, and Applications' is part of the series on Materials for Sustainable Energy and Development edited by Prof. G.Q. Max Lu. The series covers advances in materials science and innovation for renewable energy, clean use of fossil energy, and greenhouse gas mitigation and associated environmental technologies.
Download or read book Materials for Supercapacitor Applications written by M. Aulice Scibioh and published by Elsevier. This book was released on 2020-01-26 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials for Supercapacitor Applications provides a snapshot of the present status of this rapidly growing field. It covers motivations, innovations, ongoing breakthroughs in research and development, innovative materials, impacts, and perspectives, as well as the challenges and technical barriers to identifying an ideal material for practical applications. This comprehensive reference by electro-chemists explains concepts in materials selection and their unique applications based on their electro-chemical properties. Chemists, chemical and electrical engineers, material scientists, and research scholars and students interested in energy will benefit from this overview of many important reference points in understanding the materials used in supercapacitors. Provides an overview of the formulation for new materials and how to characterize them for supercapacitor applications Describes all the information on the available materials for supercapacitor applications Outlines potential material characterization methods Discusses perspectives and future directions of the field
Download or read book 2D Materials for Energy Storage and Conversion written by Suresh C. Pillai and published by IOP Publishing Limited. This book was released on 2021-11-28 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference text provides a comprehensive overview of the latest developments in 2D materials for energy storage and conversion. It covers a wide range of 2D materials and energy applications, including 2D heterostructures for hydrogen storage applications, cathode and anode materials for lithium and sodium-ion batteries, ultrafast lithium and sodium-ion batteries, MXenes for improved electrochemical applications and MXenes as solid-state asymmetric supercapacitors. 2D Materials for Energy Storage and Conversion is an invaluable reference for researchers and graduate students working with 2D materials for energy storage and conversion in the fields of nanotechnology, electrochemistry, materials chemistry, materials engineering and chemical engineering. Key Features: Provides a comprehensive overview of the latest developments in 2D materials for energy storage and conversion technologies Covers the most promising candidates for radically advanced energy storage Covers 2D heterostructures and provides a holistic view of the subject Includes 2D materials beyond graphene, defects engineering, and the main challenges in the field