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Jikei, Mitsutoshi. "Formation kinetics of polyarylene sulfides /". Electronic version of summary, 1993. http://www.wul.waseda.ac.jp/gakui/gaiyo/.pdf.
Pełny tekst źródłaManolopoulos, Helen. "Metal sulfides in oxidizing freshwater systems /". *McMaster only, 2001.
Znajdź pełny tekst źródłaRatmann, Cristiane Wienke Raubach. "Metal sulfides: photoluminescence and photocatalytic properties". Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/6279.
Pełny tekst źródłaUniversidade Federal de Minas Gerais
In this work we report an experimental and theoretical study of photoluminescence (PL) and photocatalytic activity of pure metal sulfides and systems furnished prepared by microwave assisted solvothermal (MAS) method. The theoretical model of the decorated system was created in order to analyze the electronic transition, especially in their interfaces. The results show that the system interface decorated (core-shell) produces an electron charge transfer of holes from cadmium sulfide (CdS) to zinc sulfide (ZnS), which helps increase the PL and photocatalytic activity of the system. For the pure systems, was observed the efficacy of the method synthesis employed verified that the process for obtaining the ZnS and calcium sulfide (CaS) was extremely important. Through the theoretical models was possible to evaluate the influence caused by the solvothermal influence caused by the MAS method. The variation in the synthesis parameters shows a direct influence on the PL properties of sulfides obtained which can be attributed to structural organization. The theoretical results how this order and disorder of the system can affect these properties of the obtained materials.
Neste trabalho relata-se um estudo teórico e experimental da atividade fotoluminescente (FL) e fotocatalítica de sulfetos metálicos puros e em sistemas decorados preparados por intermédio do método solvotérmico assistido por micro-ondas. O modelo teórico do sistema decorado foi criado de forma a analisar a transição eletrônica, principalmente nas suas interfaces. Os resultados mostram que a interface do sistema decorado (core-shell) produz uma transferência de carga do elétron do sulfeto de cádmio (CdS) para os buracos do sulfeto de zinco (ZnS), o que ajuda a aumentar a atividade fotoluminescente e fotocatalítica do sistema. Para os sistemas puros, observou-se a eficácia do método de síntese empregado, sendo verificado que o processo de obtenção do ZnS e sulfeto de cálcio (CaS) foi de extrema importância. Por intermédio dos modelos teóricos foi possível avaliar a influência causada pelo método. A variação nos parâmetros de síntese mostra uma influência direta nas propriedades FL dos sulfetos obtidos que pode ser atribuída a organização estrutural. O modelo teórico mostra como essa ordem e desordem do sistema podem afetar essas propriedades dos materiais obtidos.
Stani´c, Vesha. "Sol-gel processing of metal sulfides". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21641.pdf.
Pełny tekst źródłaSenior, James Daniel. "Atropisomerism in biaryl sulfides and sulfones". Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498670.
Pełny tekst źródłaStephens, Ifan Erfyl Lester. "Polysulfide electrocatalysis at transition metal sulfides". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608910.
Pełny tekst źródłaRamasamy, Karthik. "New molecular precursors for metal sulfides". Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/new-molecular-precursors-for-metal-sulfides(49bcd8c0-4a37-4eb1-892e-7a7973f8f3cd).html.
Pełny tekst źródłaEghbali, Nicolas Dara. "The chemistry of novel cyclic diesters : dialkoxy disulfide, thionosulfite and carbonate". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103380.
Pełny tekst źródłaThe synthesis of new cyclic dialkoxy-disulfides is described in Chapter 3. Five new molecules have been synthesized and fully characterized. An X-ray structure was obtained for the 2,3-furandimethylene dialkoxy disulfide. The substrates were prepared in an attempt to rationalize some of the existing limitations of the synthetic methodology.
The relationship and possible interconversion between the newly prepared cyclic dialkoxy disulfides and their structural thionosulfite isomers were investigated. Benzene dimethanoate disulfide was successfully converted to its structural thionosulfite isomer under acidic conditions. Further investigations show the existence of a reversible sulfur extrusion process between thionosulfite and sulfoxylate. This sequential transformation brings the first chemical demonstration that branched bond sulfur can indeed be involved in sulfur extrusion as was first predicted by Foss in 1950.
Finally, a highly efficient method to convert alkenes and CO2 into cyclic carbonates directly in water is presented in the second part of the thesis. Using N-bromosuccinimide (NBS) together with 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU) in water, alkenes were converted into cyclic carbonates nearly quantitatively. Cyclic carbonates were also formed efficiently by using a catalytic amount of bromide ion together with aqueous hydrogen peroxide.
Recatalá, Ferrandis David. "Photoactive Materials Based on Molybdenum Cluster Sulfides". Doctoral thesis, Universitat Jaume I, 2015. http://hdl.handle.net/10803/296561.
Pełny tekst źródłaCoordination Chemistry deals with the synthesis and study of the physicochemical properties of metal complexes. Cluster Chemistry is a subfield of Coordination Chemistry, which focuses on the functionalization of complexes in which two or more metal atoms are directly bonded. Over the past few years, Cluster Chemistry has attracted a growing interest among scientists from diverse areas, mainly due to the fascinating properties of these compounds. A historical evolution of the term cluster, as well as an outline of the role of coordinated ligands and structural types in the final properties of metal clusters are provided in Chapter 1.
This PhD Thesis is devoted to the synthesis, characterization and applications of two families of group VI metal clusters containing dithiolene or diimine ligands, as detailed in Chapter 2. The synthetic approaches employed for the preparation of a series of dinuclear M2Q2S2 cluster chalcogenides (M = Mo, W; Q = O, or S) bearing bifunctional dithiolene ligands are described in Chapter 3. These metal clusters present great potential for the design of heterometallic systems.
Chapter 4 is concerned with the preparation of an extensive family of mixed-ligand diimine-halide (or diimine-dithiolene) trinuclear molybdenum sulfides based on the Mo3S7 core. A great number of bipyridine and phenanthroline derivatives have been coordinated to these Mo3S7 units. The most important feature of the resulting cluster complexes of formula Mo3S7X4(diimine), where X = Cl, or Br, is their crystallization as [Mo3S7X4(diimine)·X]- aggregates, in which the sulfur axial atoms participate in non-bonding interactions with halide anions.
The physicochemical properties of both series of metal clusters mentioned above are explored in Chapters 5 and 6. The luminescence properties of bis(dithiolene) M2Q2S2 clusters (M = Mo, W; Q = O, or S), together with those of Mo3S7 clusters functionalized with imidazophenanthroline ligands are detailed in Chapter 5. These diimine Mo3S7 complexes exhibit luminescent anion sensing behavior. The optical limiting capabilities of both series of compounds, namely M2Q2S2- and Mo3S7-based clusters, are also described in Chapter 5 with the aim of finding correlations between molecular structures and third-order nonlinear optical functions.
Chapter 6 examines the electro- and photocatalytic activity of diimine Mo3S7 clusters immobilized on TiO2 nanoparticles toward the hydrogen evolution reaction. This study has been stimulated by the analogy between the structure of Mo3S7 and the catalytic active sites of MoS2 nanoparticles. The electrochemical properties of these TiO2 electrodes are assessed in two different media, that is, aqueous perchloric acid and sulfide-sulfite mixtures. The role of the diimine ligands in the adsorption process is also described in this Chapter.
All experimental procedures employed in this work, together with the characterization of all compounds are presented in Chapter 7. Finally, the general conclusions of this PhD Thesis are provided in Chapter 8.
Zuo, Yong. "Nanostructured Metal Sulfides for Electrochemical Energy Conversion". Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670925.
Pełny tekst źródłaEn esta tesis, se produjeron y optimizaron cuatro catalizadores nanoestructurados basados en Cu2S y SnS2 para mejorar su rendimiento hacia la conversión de energía electroquímica. El Capítulo 1 presentó una introducción general para explicar la motivación del tema de tesis. En el capítulo 2, las matrices de las nanovarillas de Cu2S se sintetizaron in situ sobre un sustrato de cobre metálico para la reacción electroquímica de evolución de oxígeno (OER). Se aplicaron herramientas de caracterización adecuadas para investigar la transformación en la operación OER, durante la cual las matrices iniciales de las nanovarillas Cu2S in situ cambió a nanohilos de CuO. En particular, el CuO derivado de Cu2S mostró un rendimiento de OER significativamente mejor cuando comparado al de CuO preparado mediante el recocido. En el capítulo 3, se detalló un proceso basado en una solución de inyección en caliente para producir nanoplacas ultrafinas SnS2 (NPL). Posteriormente, se cultivóPt en su superficie mediante la reducción in situ de una sal de Pt. Posteriormente se probó el rendimiento fotoelectroquímico (PEC) de los fotoanodes hacia la oxidación del agua. Los fotoanodes de SnS2-Pt optimizados proporcionaron densidades de fotocorriente significativamente más altas que el SnS2 desnudo (seis veces). Se analizó el efecto de Pt. En el capítulo 4, se informó una tinta molecular simple para cultivar capas de SnS2 nanoestructuradas directamente sobre sustratos conductores. Tales capas nanoestructuradas en FTO se caracterizaron por excelentes densidades de fotocorriente. Se utilize la misma estrategia para producir compuestos de grafeno-SnS2, recubrimientos ternarios SnS2-xSex, capas de SnSe2 de fase pura e incluso polvo de SnS2 a gran escala. En el capítulo 5, el SnS2 nanoestructurado con diferentes morfologías se probaron como ánodos LIB en primer lugar para encontrar que los NPL de SnS2 delgados proporcionaban el mayor rendimiento. Posteriormente, se desarrolló una estrategia de síntesis coloidal para cultivar los mismos NPL de SnS2 dentro de una matriz de g-C3N4 (CN) poroso y placas de grafito (GP) y se probaron para la aplicación LIB. Tales compuestos jerárquicos SnS2/CN/GP mostraron excelentes propiedades electroquímicas, lo que se atribuye a la sinergia creada entre los tres componentes como se investigó.
Grippa, Alexander. "Structural investigation of Nb-based layer sulfides". Doctoral thesis, Stockholm University, Department of Physical, Inorganic and Structural Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-177.
Pełny tekst źródłaIn this work we have investigated the intercalation of electron-donors between NbS2 slabs in Nb-based layer sulfides.
Two series of Sr substituted Nb-based misfit sulfides belonging to the 1.5Q/1H and 1Q/1H series of misfit layer compounds have been synthesised. For large lanthanides (Ln=La, Ce), only the 1Q/1H compounds formed whereas for smaller lanthanides and yttrium, both types of phases can be obtained. The crystal structure of misfit sulfide (Pr0.55Sr0.45S)1.15NbS2 has been refined using the composite approach. In the Q-slab, Pr-atoms are partly replaced by Sr with a random distribution over one cation position. The crystal structure of misfit sulfide [(Sm1/3Sr2/3S)1.5]1.15NbS2 belonging to the 1.5Q/1H series have also been determined. The obtained results suggest a preferred occupancy of the cation positions in the slab where Sr atoms mainly occupy positions on the exterior of the slab while Sm atoms are in the center of the slab. The (La1-xSrxS)1.15NbS2 solid solution (0.1 An attempt to synthesize SrxNbS2 (0.1≤x≤0.5) intercalates was made but single phases were not obtained and increasing the temperature from 1000оС to 1100оС leads to the decomposition of these intercalates. Single crystals of Sr0.22Nb1.05S2 and Sr0.23NbS2 were found and their structures were determined. The structures belong to two different types of packings with statistical distribution of Sr between layers. A new superconducting sulfide, "EuNb2S5", was investigated by ED and HREM and its structure model consisting of Nb7S14 and (Eu3S4)2 slabs alternating along the c-axis is suggested. An attempt to suggest a model for the structure of "SrNb2S5" by means of X-ray single crystal diffraction was made. The proposed structure consists of two types of slabs: a Nb7S14 and a [Sr6(NbS4)2S] slab with niobium in tetrahedral coordination. It is shown that "SrNb2S5" and "EuNb2S5" are have similar structures. For the first time, single crystals of the complex sulfide BaNb0.9S3 have also been studied by means of X-ray single crystal diffraction. The single crystal refinement and EDX analysis showed the existence of cation vacancies at the niobium position. BaNb0.9S3 has also been studied by ED and no superstructure was found which implies that and the vacancies are statistically distributed. No improvement of the magnetic properties of the studied compounds was observed in comparison to NbS2.
Grippa, Alexander Yu. "Structural investigation of Nb-based layer sulfides /". Stockholm : Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-177.
Pełny tekst źródłaGammon, Jonathan J. "Chiral base-mediated desymmetrisation of phosphine sulfides". Thesis, University of York, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516645.
Pełny tekst źródłaRees, David Alan. "Synthesis of alkaline earth transition metal sulfides". Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311775.
Pełny tekst źródłaDinnage, Christopher Walker. "Molecular precursor routes to transition metal sulfides". Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252054.
Pełny tekst źródłaLukashev, Pavel. "Crystal and Electronic Structure of Copper Sulfides". Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1164213394.
Pełny tekst źródłaGuo, Qin. "Synthesis and oxidation of vinyl stannyl sulfides". Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/187512.
Pełny tekst źródłaCunningham, Sharron Anne. "Soluble lanthanide thiolate complexes". Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367207.
Pełny tekst źródłaGilfillan, Joanne Criseyde. "The structure and microbiology of floating sulphide oxidising biofilms". Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1003962.
Pełny tekst źródłaColbow, Kevin Michael. "Lithium intercalation in titanium based oxides and sulfides". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27860.
Pełny tekst źródłaScience, Faculty of
Physics and Astronomy, Department of
Graduate
Yükseker, Ömer Kardes. "A study of molecular- and meso- tin sulfides". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58763.pdf.
Pełny tekst źródłaKaur, Rajvinder. "Non-hydrolytic Sol-gel Synthesis of Tin Sulfides". University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404243055.
Pełny tekst źródłaZhang, Yuan. "Prepartion of multi-metal sulfides for electrochemical supercapacitors". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I014.
Pełny tekst źródłaIn recent years, electrochemical supercapacitors (ESs), as environmentally-friendly energy storage systems, are facing several challenges associated with the performance, functionality, and durability of key materials. Among different types of ESs, hybrid supercapacitors, the combination of electrodes with different energy storage mechanisms, especially the combination of electrochemical double layer capacitance (EDLC) and battery-type behavior, are expected to offer enhanced electrochemical performance. Concerning hybrid supercapacitors consisting of EDLC//battery-type electrode materials, carbonaceous materials, owing to their excellent electrical conductivity, electrochemical stability, and large specific surface area, are the most promising candidates for electrode materials with EDLC-type behavior. For electrode materials with battery-type behavior, owing to the faradaic charge transfer reactions involved in the electrochemical process, transition metal compounds can store plenty of energy and represent one of the most promising candidates for electrode materials with battery-type behavior. In this thesis, different carbonaceous materials, such as reduced graphene oxide (rGO), porous reduced graphene oxide (PrGO), and poly-ethylene dioxythiophene-Fe-900 (PF-9), are prepared through chemical oxidation and reduction methods. Moreover, transition metal compounds, such as CoS/carbonaceous support (rGO or PF-9), ZnCoS, ZnS/Ni3S2 and Sb2S3/CoS2/CrOOH, are synthesized via chemical co-precipitation and ion-exchange method. A variety of different techniques, including XPS, SEM, ICP-AES, TEM, XRD, BET, and Raman, are used to investigate the physicochemical performance of as-prepared materials. Their corresponding electrochemical performance is also evaluated through a 3- electrode system. Additionally, hybrid supercapacitors consisting of as-prepared carbon and transition metal electrodes are assembled, respectively, and their electrochemical performance is evaluated through the 2- electrode system
Hall, Donald Lewis. "Fluid evolution during metamorphism and uplift of the massive sulfide deposits at Ducktown, Tennessee, U.S.A". Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54186.
Pełny tekst źródłaPh. D.
SWANSON, DALE DORSETT. "ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES OF THIOETHER COORDINATION COMPLEXES (CYCLIC VOLTAMMETRY, OCTAHEDRAL LOW-SPIN METALS, BLUE COPPER PROTEINS, ELECTRON PARAMAGNETIC RESONANCE)". Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188102.
Pełny tekst źródłaGibbard, Kevin. "High temperature synthesis of cerium sulfides and kinetic modeling". [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010471.
Pełny tekst źródłaQu, Deyu. "The mechanism of adsorption of sulfides on gold(111)". Thesis, University of Ottawa (Canada), 1998. http://hdl.handle.net/10393/4384.
Pełny tekst źródłaQu, Deyu. "The mechanism of adsorption of sulfides on Au(111)". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ36735.pdf.
Pełny tekst źródłaMizera, Michel-Adam. "Ignition temperature measurements of metallic sulfides in SHS processes". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37274.pdf.
Pełny tekst źródłaCondon, Brian D. "Stereoselective bond formation via lithiation of asymmetric acyclic sulfides". Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/29911.
Pełny tekst źródłaMizera, Michel Adam. "Ignition temperature measurements of metallic sulfides in SHS processes". Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28007.
Pełny tekst źródłaSundberg, Jill. "Triboactive Low-Friction Coatings Based on Sulfides and Carbides". Doctoral thesis, Uppsala universitet, Oorganisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-230989.
Pełny tekst źródłaPorcelloni, Marina. "Synthesis and application of chiral sulfides in asymmetric epoxidation". Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272057.
Pełny tekst źródłaNowosielska, Anna. "The leaching of metal sulfides in ammoniacal carbonate solutions". Thesis, Nowosielska, Anna (2017) The leaching of metal sulfides in ammoniacal carbonate solutions. Honours thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/40607/.
Pełny tekst źródłaWalton, Richard I. "The characterisation and structure of amorphous and poorly crystalline transition-metal chalcogenides". Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388467.
Pełny tekst źródłaSchumer, Benjamin Nathan, i Benjamin Nathan Schumer. "Mineralogy of Copper Sulfides in Porphyry Copper and Related Deposits". Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626163.
Pełny tekst źródłaKu, James Chih-Hung. "Studies on the electrochemistry of some mineral and organic sulfides". Thesis, University of Ottawa (Canada), 1985. http://hdl.handle.net/10393/4806.
Pełny tekst źródłaXie, Ning. "Lewis acid catalyzed oxidation of sulfides and sulfoxides by permanganate". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq35823.pdf.
Pełny tekst źródłaPhillips, Noel William. "The environmental controls of iron(II) sulfides in natural waters". Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310360.
Pełny tekst źródłaEversfield, Sharon Gail. "An investigation of some disordered transition metal sulfides and cyanides". Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288770.
Pełny tekst źródłaPeters, Emily Sarah. "Precursor synthesis and chemical vapour deposition of transition metal sulfides". Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408505.
Pełny tekst źródłaHerbert, Francis William. "Mechanisms governing the growth, reactivity and stability of iron sulfides". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98126.
Pełny tekst źródłaThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 135-140).
The kinetics of electrochemical processes in ionic materials are fundamentally governed by dynamic events at the atomic scale, including point defect formation and migration, and molecular interactions at the surface. A corrosion system comprising an iron sulfide film (passive layer) formed on iron or steel in contact with an hydrogen sulfide (H₂S)- rich fluid can thus, in principle, be modeled by a series of unit reaction steps that control the rate of degradation under given thermodynamic conditions. This overarching thesis goal necessitates a concerted experimental and computational approach to determine the relevant kinetic parameters such as activation barriers Ea and rate constants v₀ for the homogeneous and heterogeneous reactions of interest. These fundamental values can be obtained experimentally via temperature-dependent measurements on pure, model iron sulfide samples. This thesis therefore consists of three case studies on the stable Fe-S phases pyrrhotite (Fe₁-xS) and pyrite (FeS₂) to identify the elementary corrosion mechanisms and their kinetic parameters. Pyrrhotite is of interest because the off-stoichiometry of this phase leads to relatively rapid bulk processes such as diffusion; pyrite has a comparitively inert bulk but this work showed that it has a chemically labile surface. The first study focuses on two basic, rate-controlling steps in the growth of pyrrhotite: cation diffusion and sulfur exchange at the surface. First, iron self-diffusivity *DFe is determined across the temperature range 170-400 °C through magnetokinetic studies of the diffusion-driven "[lambda]" magnetic transformation, as well as direct tracer diffusion measurements in Fe₁-xS crystals using secondary ion mass spectrometry (SIMS). This range encompasses the sponteneous magnetic and structural order-disorder temperature TN = 315 °C in pyrrhotite. The effect of spontaneous magnetization below TN is to increase the Fe vacancy migration energy by a combined 40% increasing Ea for diffusion from 0.83 eV in paramagnetic Fe₁-xS to ~1.20 eV in the fully magnetized state. An extrapolation of the Arrhenius law from the paramagnetic regime would therefore overestimate actual diffusivities by up to 10² times at 150 °C. Second, the surface exchange of sulfur from H₂S into the solid state in Fe₁-xS is measured using electrical conductivity relaxation, yielding Ea = 1.1 eV for sulfur incorporation into pyrrhotite. With their similar thermal dependence, there is no clear temperature crossover from cation diffusion- to surface exchange-limiting regimes, or vice versa. Instead, surface exchange is expected to constrain pyrrhotite growth for films under ~100 [mu]m thickness, beyond which diffusion becomes the rate limiting mechanism, independent of external driving factors such as temperature. The second study explores the role of surface electronic states on the electrochemical reactivity of pyrite. Charge transfer between a solid surface and an adsorbate such as H₂S requires the mutual availability of filled/empty electronic states at the same energy level. The semiconducting FeS₂(100) surface is predicted to have intrinsic surface states (SS's) from Fe and S dangling bonds, as well as extrinsic SS's related to delocalized defects at the surface, both of which would affect charge transfer characteristics. A novel, broadly-applicable methodology is developed in this thesis to quantify the energy and density of these SS's, based on experimental scanning tunneling microscopy / spectroscopy (STM/STS) in conjunction with first principles tunneling current modeling. As a result, a decreased surface band gap Eg of 0.4 eV, compared to 0.95 eV in bulk pyrite, is measured. The findings highlight the need to differentiate between bulk and surface electronic structure when assessing heterogeneous reactivity, and have implications for the use of FeS₂ in potential technological applications, for example as a photovoltaic adsorber. Finally, the dynamics of point defect formation and clustering on FeS₂(100) under high-temperature, reducing conditions are investigated to understand the stability of the surface under extreme conditions. Synchrotron x-ray photoelectron spectroscopy (XPS) is used to measure a formation energy [delta]Hf for sulfur vacancies in the topmost atomic layer of 0.1 eV up to approximately 240 °C. Above this temperature, however, point defects are shown to condense into surface pits as measured by scnaning tunneling microscopy (STM). The combined, experimental XPS and STM results are replicated with high precision by a kinetic Monte Carlo (kMC) simulation, developed by Aravind Krishnamoorthy towards his doctoral thesis, of surface degradation on realistic length-and timescales of 10-¹⁰ - 10-⁷ m and up to several hours, respectively. The findings have implications for the initiation of surface breakdown via pitting in ionic passive films, as well as providing a broader understanding of the non-stoichiometry of the pyrite surface. The common thread is a focus on events at the atomic and electronic scale, with an emphasis on point defects. The results thereby facilitate a bottom-up approach to modeling electrochemical processes such as corrosion in Fe-S phases, in which the unit steps are cast into probabilistic simulation tools. While the three studies here comprise only a partial examination of the atomic-scale events regulating the behavior of Fe-S passive layers, this approach makes inroads towards more accurate component lifetime prediction and the design of robust materials for aggressive environments. Moreover, the fundamental surface and bulk physical chemistry of iron sulfides explored in this work has implications beyond corrosion to other uses of these materials, including potential magnetic devices (Fe₁-xS) and earth-abundant photovoltaic and photoelectrochemical adsorbers (FeS₂).
by Francis William Herbert.
Ph. D.
Brown, Bruce N. "The Influence of Sulfides on Localized Corrosion of Mild Steel". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1386325647.
Pełny tekst źródłaYavuz, Sinem. "Seismic characterization of Volcanogenic massive sulfides – the Semblana orebody, Portugal". Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/48.
Pełny tekst źródłaYoung, Aidan Gerard, i n/a. "Chemistry at cadmium sulfide surfaces". University of Otago. Department of Chemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080806.164202.
Pełny tekst źródłaMARTINS, ELAINE A. J. "Sintese e caracterizacao de sulfetos metalicos em baixas temperaturas por reacao solido-solido utilizando-se gerador de sulfeto". reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11009.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Mayende, Lungisa. "Isolation of a Clostridium Beijerinckii sLM01 cellulosome and the effect of sulphide on anaerobic digestion". Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1004032.
Pełny tekst źródłaWoolfall, Marc P. "Novel mediators for oxidation using hydrogen peroxide". Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367254.
Pełny tekst źródłaFeaviour, Mark R. "Synthesis, characterisation and reactions of molybdenum and tungsten chalcogenides". Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314313.
Pełny tekst źródłaRaza, Muhammad Rehail. "Synthesis and chemistry of novel chiral sulfilimines". Thesis, Keele University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311151.
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