Download or read book Design Synthesis and Characterization of Novel Semiconducting Metal Chalcogenides with Multifunctional Properties written by and published by . This book was released on 2008 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal chalcogenides possess a wide range of interesting chemical and physical properties, including low-temperature superconductivity, semiconductivity, ionic conductivity, intercalation, and optical properties. To expand chalcogenides beyond their traditional applications, it is desirable to generate novel chalcogenide materials with multifunctionality for uses in the areas of catalysis, separation, ion exchange, and gas storage by modifying the framework architectures and tuning the chemical components. The primary focus of my Ph. D. study is to design and synthesize chalcogenide materials with new structures and interesting multifunctional properties. The large variety of chemical compositions and structures make it possible to tune the properties, such as band gap, luminescence, pore size, surface area, and thermal stability. Most of the synthesis has been carried out using solvothermal reactions refs in pyrex tube or teflon lined autoclaves. Novel three-dimensional (3D) microporous chalcogenides constructed on building units [M-Sn-Q]n- (M=Zn, Cd, Mn; Q=S, Se) have been obtained. Their structures have been characterized by both single crystal and powder X-ray diffraction methods. Optical diffuse reflectance experiments have indicated that these compounds are semiconductors with intermediate band gaps between 1.5~2.9eV. The successful doping/substitution of 5%~20% Mn and Se in the [Zn-Sn-S]n- structure allows systematic tuning of the band gap and optical properties of this semiconductor compound. All compounds show a high thermal stability over 400°C. Our studies also show that the guest molecules and cations residing in the open frameworks are exchangeable. Another novel two dimentional ion sulfide [Fe(en)3]·[Fe16S20]·en compound was synthesized as well. UV-Vis reflectance spectroscopy showed a very low absorption coefficient and small band gap ~0.5eV. Doping/substitution experiments with Co and Mn replacing Fe were carried out and the properties will be discussed. In summary, this work has provided examples of rational synthesis and property tuning of new functional materials with new structure types, and demonstrated structure-property correlation in metal chalcogenide based compounds. It has provided useful information for the future developments of material synthesis with desired multifunctionality.

Download or read book Design Synthesis and Applications of One Dimensional Chalcogenide Hetero Nanostructures written by Tao-Tao Zhuang and published by Springer. This book was released on 2018-04-18 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the design and synthesis of novel one-dimensional colloidal chalcogenide hetero-nanostructures for enhancing solar energy conversion applications. Semiconducting nanomaterials are particular attractive for energy conversion due to the quantum confinement effects dictating their unique optical and electronic properties. Steering the photo-induced charge-flow based on unique bandgap alignment in semiconductor heterojunctions is critical for photo-electric/chemical conversion. The author presents the controllable preparation strategies to synthesize 1D chalcogenide hetero-nanostructures with various fine structures, further been used as excellent template materials for preparing other novel and complex hybrid architectures through a series of chemical transformations. The heterogeneous growth mechanisms of novel hetero-nanostructures is studied for developing a facile and general method to prepare more novel heterostructures. The band gap structure simulations, detailed charge carrier behaviour and unique solar energy conversion properties of the prepared hybrid nanostructures are deeply investigated. This work would open a new door to rationally designing hybrid systems for photo-induced applications.

Download or read book Synthesis and Characterization of Copper Based Ternary Metal Chalcogenides written by Jose Javier Sanchez Rodriguez and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current climate crisis is a great concern to humankind due to the devastating effects of the consistent rise of anthropogenic greenhouse gases. A viable alternative to reducing greenhouse gas emissions is the development of solar harvesting technologies. The need to develop new semiconductor materials with more capacity to absorb light and convert it into electricity is rapidly growing. A promising class of materials for this purpose are copper-based ternary chalcogenides such as CuCrS2, CuSb1-xBixS2, and Cu3VS4.The synthesis and characterization of copper-based ternary chalcogenides nanocrystals (NCs) have gained popularity in the scientific community due to their novel, physical, chemical, optical, electronic, magnetic, and mechanical properties. NCs can be precursors to the next-generation nanoparticle-based thin film solar cells. This generation of thin film solar cells is advantageous in terms of the compounding benefits. Materials in the forms of NCs offer size, and morphology-dependent properties, high absorption coefficients, and tunable bandgaps. Nanoparticle-based thin film solar cells use very thin layers of material, lowering their production cost while making the systems flexible, more efficient, and compatible with new and existing infrastructure.This dissertation addresses several challenging issues and realizes the successful fabrication of novel CuCrS2, CuSb1-xBixS2 (x=1, 0.18), and Cu3VS4 NCs-based thin films. These systems were synthesized using two different thermal decomposition methods: heat-up (HU) and hot-injection (HI). This dissertation presents a detailed study involving the synthesis and characterization of the above-mentioned semiconductors by applying the developed nano-to-thin film approach. Their optical and electrical properties were explored, and their respective optical bandgaps were determined using UV-vis and electron energy loss spectroscopy (EELS). The ability of the fabricated thin films to generate a photocurrent under sunlight irradiation was explored, reporting their responsivities and current conversion efficiencies.

Download or read book Synthesis and Characterization of New Mixed metal Chalcogenides and Oxychalcogenides written by Theodore Dennis Brennan and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Characterization of Transition Metal Oxide Based Functional Materials for Multi phase Catalytic Applications written by Chung-Hao Kuo and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Transitional Metal Chalcogenides written by Douglas A. Keszler and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of New Low Dimensional Transition Metal Chalcogenides written by Steven Arthur Sunshine and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Controlled Synthesis and Characterization of Magnetic Chalcospinels Nanocrystals written by Farhad Akbari Afkhami and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary and ternary metal chalcogenides have become well-known materials among chemists, physicists, material scientists, and other researchers of the field, and they have attracted significant attention because of their novel chemical, magnetic, electronic, mechanical and optical properties. Among the metal chalcogenides, chromium-based chalcospinels ACr2X4 (A = Cu, Co, Fe, Cd, and Hg; X = S, Se, and Te) have gained significant attention because they are a notable class of magnetic materials such as semiconductors, magnetic metals, and insulators. In this work, a general overview of binary and ternary metal chalcogenides and their nanocrystals has been provided. We have also provided an overview of the wet-chemical colloidal methods as an important approach to size and shape-controlled synthesize of nanocrystals. We have also discussed the importance of metal doping reactions as a pathway to create previously unavailable multielemental materials for high-performance applications. In this set of studies, colloidal nanocrystals of chromium-based chalcospinels of CuCr2S4 and CuCr2Se4 have been synthesized via hot-injection and heat-up methods and were characterized using experimental methodology comprised of different microstructural and structural tests. The magnetic properties of these nanocrystals have also been studied. The next studied system was Cr-doped pyrite CuSe2 nanocrystals, eventually leading to the observation of significant enhancement of ferromagnetic moment by Cr-doping in octahedral sites of the pyrite structure. We performed a unique reaction in which nanocrystals of CrxCu1-xSe2 (x = 0.1-0.5) formed in the pyrite phase, which is not stable in bulk form. The host p-CuSe2 nanocubes did also undergo a degradation influenced by the reaction temperature and the doping of Cr3+ ions in the pyrite crystal structure. The Cr-doped nanocrystals of the pyrite phase were formed during the heat-up procedure and by increasing the reaction temperature transformed to CuCr2Se4 spinel nanocrystals. To the best of our knowledge, no cationic substitution of chromium for copper has been reported on pyrite CuSe2 systems so far, likely due to the significant size difference between chromium and copper. Therefore, the results of this work are a powerful approach for the design and fabrication of new multielemental materials that may not be stable in the bulk form.

Download or read book Synthesis and Characterization of Metal Chalcogenide MQ2 nanoparticles written by Nicole Christin Zink and published by . This book was released on 2006 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Characterization of Novel Materials to Construct High energy density Rechargeable Cells written by Zheng Yue and published by . This book was released on 2018 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Atomic Scale Derivatives and Clusters of Transition Metal Chalcogenides written by Tianyang Li and published by . This book was released on 2016 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overall, using titanium and vanadium chalcogenides as model systems, a solution phase synthesis methodology has been develop to create the original two dimensional organic intercalated transition metal chalcogenides, their atomic scale one dimensional chain derivatives and low temperature cluster and precursor phases. The electronic structures and the Li intercalation of the new phases are studied to understand the correlation of properties and structures, leading towards the design and discovery of more useful functional hybrid materials.

Download or read book Photocatalytic Hydrogen Evolution written by Misook Kang and published by MDPI. This book was released on 2020-06-17 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy crises and global warming pose serious challenges to researchers in their attempt to develop a sustainable society for the future. Solar energy conversion is a remarkable, clean, and sustainable way to nullify the effects of fossil fuels. The findings of photocatalytic hydrogen production (PCHP) by Fujishima and Honda propose that “water will be the coal for the future”. Hydrogen is a carbon-free clean fuel with a high specific energy of combustion. Titanium oxide (TiO2), graphitic-carbon nitride (g-C3N4) and cadmium sulfide (CdS) are three pillars of water splitting photocatalysts owing to their superior electronic and optical properties. Tremendous research efforts have been made in recent years to fabricate visible or solar-light, active photocatalysts. The significant features of various oxide, sulfide, and carbon based photocatalysts for cost-effective hydrogen production are presented in this Special Issue. The insights of sacrificial agents on the hydrogen production efficiency of catalysts are also presented in this issue.

Download or read book Applications of Chalcogenides S Se and Te written by Gurinder Kaur Ahluwalia and published by Springer. This book was released on 2018-06-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to a wide range of applications for elements in Group 16 of the periodic table, such as, optical fibers for communication and sensing, X-ray imaging, electrochemical sensors, data storage devices, biomedical applications, photovoltaics and IR detectors, the rationale for these uses, the future scope of their applications, and expected improvements to existing technologies. Following an introductory section, the book is broadly divided into three parts—dealing with Sulfur, Selenium, and Tellurium. The sections cover the basic structure of the elements and their compounds in bulk and nanostructured forms; properties that make these useful for various applications, followed by applications and commercial products. As the global technology revolution necessitates the search for new materials and more efficient devices in the electronics and semiconductor industry, Applications of Chalcogenides: S, Se, and Te is an ideal book for a wide range of readers in industry, government and academic research facilities looking beyond silicon for materials used in the electronic and optoelectronic industry as well as biomedical applications.

Download or read book Chalcogenide Based Nanomaterials as Photocatalysts written by Mohammad Mansoob Khan and published by Elsevier. This book was released on 2021-04-07 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chalcogenide-Based Nanomaterials as Photocatalysts deals with the different types of chalcogenide-based photocatalytic reactions, covering the fundamental concepts of photocatalytic reactions involving chalcogenides for a range of energy and environmental applications. Sections focus on nanostructure control, synthesis methods, activity enhancement strategies, environmental applications, and perspectives of chalcogenide-based nanomaterials. The book offers guidelines for designing new chalcogenide-based nanoscale photocatalysts at low cost and high efficiency for efficient utilization of solar energy in the areas of energy production and environment remediation. Provides information on the development of novel chalcogenide-based nanomaterials Outlines the fundamentals of chalcogenides-based photocatalysis Includes techniques for heterogeneous catalysis based on chalcogenide-based nanomaterials

Download or read book Electrochemistry of Metal Chalcogenides written by Mirtat Bouroushian and published by Springer Science & Business Media. This book was released on 2010-04-23 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author provides a unified account of the electrochemical material science of metal chalcogenide (MCh) compounds and alloys with regard to their synthesis, processing and applications. Starting with the chemical fundamentals of the chalcogens and their major compounds, the initial part of the book includes a systematic description of the MCh solids on the basis of the Periodic Table in terms of their structures and key properties. This is followed by a general discussion on the electrochemistry of chalcogen species, and the principles underlying the electrochemical formation of inorganic compounds/alloys. The core of the book offers an insight into available experimental results and inferences regarding the electrochemical preparation and microstructural control of conventional and novel MCh structures. It also aims to survey their photoelectrochemistry, both from a material-oriented point of view and as connected to specific processes such as photocatalysis and solar energy conversion. Finally, the book illustrates the relevance of MCh materials to various applications of electrochemical interest such as (electro)catalysis in fuel cells, energy storage with intercalation electrodes, and ion sensing.

Download or read book Metal Chalcogenide Nanostructures for Renewable Energy Applications written by Ahsanulhaq Qurashi and published by John Wiley & Sons. This book was released on 2014-11-21 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first ever reference book that focuses on metal chalcogenide semiconductor nanostructures for renewable energy applications encapsulates the state-of-the-art in multidisciplinary research on the metal chalcogenide semiconductor nanostructures (nanocrystals, nanoparticles, nanorods, nanowires, nanobelts, nanoflowers, nanoribbons and more). The properties and synthesis of a class of nanomaterials is essential to renewable energy manufacturing and this book focuses on the synthesis of metal chalcogendie nanostructures, their growth mechanism, optical, electrical, and other important properties and their applications in different diverging fields like photovoltaics, hydrogen production, theromelectrics, lithium battery, energy storage, photocatalysis, sensors. An important reference source for students, scientists, engineers, researchers and industrialists working on nanomaterials-based energy aspects associated with chemistry, physics, materials science, electrical engineering, energy science and technology, and environmental science.