abstract: Solar energy is a promising alternative for addressing the world's current and future energy requirements in a sustainable way. Because solar irradiation is intermittent, it is necessary to store this energy in the form of a fuel so it can be used when required. The light-driven splitting of water into oxygen and hydrogen (a useful chemical fuel) is a fascinating theoretical and experimental challenge that is worth pursuing because the advance of the knowledge that it implies and the availability of water and sunlight. Inspired by natural photosynthesis and building on previous work from our laboratory, this dissertation focuses on the development of water-splitting dye-sensitized photoelectrochemical tandem cells (WSDSPETCs). The design, synthesis, and characterization of high-potential porphyrins and metal-free phthalocyanines with phosphonic anchoring groups are reported. Photocurrents measured for WSDSPETCs made with some of these dyes co-adsorbed with molecular or colloidal catalysts on TiO2 electrodes are reported as well. To guide in the design of new molecules we have used computational quantum chemistry extensively. Linear correlations between calculated frontier molecular orbital energies and redox potentials were built and tested at multiple levels of theory (from semi-empirical methods to density functional theory). Strong correlations (with r2 values > 0.99) with very good predictive abilities (rmsd < 50 mV) were found when using density functional theory (DFT) combined with a continuum solvent model. DFT was also used to aid in the elucidation of the mechanism of the thermal relaxation observed for the charge-separated state of a molecular triad that mimics the photo-induced proton coupled electron transfer of the tyrosine-histidine redox relay in the reaction center of Photosystem II. It was found that the inclusion of explicit solvent molecules, hydrogen bonded to specific sites within the molecular triad, was essential to explain the observed thermal relaxation. These results are relevant for both advancing the knowledge about natural photosynthesis and for the future design of new molecules for WSDSPETCs. / Dissertation/Thesis / Ph.D. Chemistry 2014

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No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Thiago André Salgueiro Soares.pdf: 4033349 bytes, checksum: 4a1bb454487e180fb4adfc6bb7d4d5a2 (MD5) Previous issue date: 2017-01-25 / CNPQ / Neste trabalho estudou-se a síntese de nanotubos (NT) a partir da liga Ti-75Ta através do processo de anodização e a sua aplicação como fotocatalisador na foto geração de hidrogênio (H₂). Através do planejamento fatorial 2³ completo foi possível a fabricação das nanoestruturas sob diferentes condições de potencial, tempo e temperatura e avaliar os feitos sob o campo elétrico do sistema (densidade de corrente) e a morfologia dos nanotubos (diâmetro e comprimento) e assim obter nanotubos com elevada área superficial especifica (62 m²/g). Os NT TiO₂-Ta₂O₅ sintetizados sob as diferentes condições experimentais foram caracterizados por microscopia eletrônica de varredura (MEV) permitindo mensurar os diâmetros e os comprimentos dos óxidos. As nanoestruturas quando formadas são amorfas necessitando de tratamento térmico para se obter a fase cristalina. A técnica de difração de Raios X (DRX) permitiu estudar a cinética de transformação das fases dos NT TiO₂-Ta₂O₅ e determinar que a temperatura de 800°C é a ideal para a obtenção das fases cristalinas sem danificar as nanoestruturas. Visando a formação de uma nova fase as amostras foram tratadas a 1000°C dando origem a um novo produto identificado como óxido misto de TiTa₂O₇, obtendo uma síntese simples e rápida para a fabricação deste material. A estrutura eletrônica foi avaliada através da técnica de espectroscopia de reflectância difusa, os NT TiO₂-Ta₂O₅ apresentaram band gap de 3,29eV, ao passo que os NT TiTa₂O₇ apresentaram band gap 3,09eV, potencializando a sua aplicação como fotocatalisador na reação de water splitting (WS). Desta forma, tentar combinar o processo de fotogeração de hidrogênio (WS) com a degradação de poluentes orgânicos é uma nova tendência mundial. Neste contexto, o glicerol foi utilizado como agente redutor e demonstrou ser um excelente agente de sacrifício, pois além de auxiliar na separação dos pares elétrons/buracos, apresentou longo tempo de estabilidade sem geração de CO₂ e a sua fotodegradação resultou na formação de dihidroxiacetona, como co-produto de alto valor agregado. Os nanotubos de sintetizados a 800°C apresentaram eficiência de conversão da energia solar em H₂ (STH) de 0,062% enquanto que os óxidos mistos apresentam STH de 0,092% resultados significativos admitindo ue são estruturas simples que permitem melhorias como a adição de catalisadores e dopantes. Além da aplicação como fotocatalisador o TiTa₂O₇ pode ser aplicado como ânodo em baterias de íon de Lítio, produto de grande impacto tecnológico. / In this work the synthesis of nanotubes (NT) from Ti-75Ta alloy (NT TiO₂-Ta₂O₅) was studied through the anodizing process and its application as photocatalyst in the hydrogen (H₂) photogeneration. Through the 2³ factorial design it was possible to fabricate nanostructures under different conditions of potential, time and temperature and to evaluate the effects under electric field of the system (current density) and the morphology of the nanotubes (diameter and length) to obtain nanotubes with Specific surface area (62 m²/g). The NT TiO₂-Ta₂O₅ synthesized as different experimental conditions were characterized by scanning electron microscopy (SEM) allowing to measure the diameters and the lengths of the oxides. As nanostructures when formed are amorphous requiring heat treatment to obtain a crystalline phase. The X-ray diffraction (XRD) technique allowed a transformation kinetics of the NT TiO₂-Ta₂O₅ phases and a temperature of 800 °C is an ideal for obtaining crystalline phases without damaging as nanostructures. Targeting a new phase formation as samples were treated at 1000 ° C to give a new product identified as TiTa₂O₇ mixed oxide, obtaining a simple and rapid synthesis for a manufacture of this material. The electronic structure was evaluated using the diffuse reflection spectroscopy technique, the NT TiO₂-Ta₂O₅ presented a band gap of 3.29eV, whereas the TiTa₂O₇ presented band gap 3.08eV, potentializing its application as a photocatalyst in the reaction of water splitting (WS). In this way, combining the hydrogen photogeneration (WS) process with a degradation of organic pollutants is a new world trend. Glycerol was used as a reducing agent and demonstrated to be an excellent reduction agent, besides assisting in the separation of e-/h+ pairs, presented long time of stability without generation of CO₂ and its photodegradation resulted in the formation of dihydroxyacetone, as coproduct of high added value. The nanotubes synthesized at 800 °C showed the conversion of solar energy to H₂ (STH) of 0.062% since the oxides are mixed have STH of 0.092% significant results admitted that are simple structures that stand out as an addition of noble metal nanoparticles and dopants. In addition to the application as a photocatalyst TiTa₂O₇ can be applied as an anode in Lithium ion batteries.

La photoelectrocatalyse de l'eau par rayonnement solaire est une solution communément proposée pour la production propre d'hydrogène. En termes de rendement solaire-à-hydrogène, un tandem dual photosystème est accepté comme la configuration plus efficace concernant les cellules photoelectrocatalytique pour la dissociation de l'eau. Ce travail s'intéresse au trioxyde de tungstène (WO3) et au bismuth vanadate (BiVO4) sous la forme de photoanodes type n en couches minces pour la complétion d'oxydation de l'eau dans la demi-réaction pour la dissociation complète de l'eau dans une cellule tandem dual photosystème photoelectrocatalytique. Ces couches minces sont fabriquées par des méthodes robustes, économiques, et extensibles de sol-gel dip coating, et caractérisées par différentes techniques pour vérifier leurs caractéristiques physiques et leur performance photoelectrochimique. WO3 et BiVO4 sont optimises par nanostructuration, modification des couches interfaciales, et addition des co-catalyseurs de surface pour améliorer les performances et la stabilité, respectivement dans des conditions acides et neutres. Ces matériaux sont couples avec une photocathode de type p en oxyde de cuivre (II) pour compléter la réaction de dissociation de l'eau. La cellule photoelectrocatalytique ainsi construite est inspirée par la littérature concernant les systèmes innovateurs de tandem dual photosystèmes. Ce travail aboutit à l'une des seules cellules de dissociation de l'eau par photoelectrocatalyse à base des oxydes de métaux, fabriquée via des techniques faciles et économiques. L'efficacité de la production solaire-à-hydrogène est de 0.01%, et applied-bias-to-photon efficacité de 0.06%. / Solar water splitting by photoelectrocatalysis is a proposed long term solution for the production of renewable hydrogen. A wired dual photosystem photoelectrocatalytic cell is thermodynamically considered to possess the highest attainable solar-to-hydrogen efficiency. To realize a photoelectrocatalytic water splitting cell for practical application, facile fabrication methods and abundant low cost materials are essential. This research investigates tungsten trioxide (WO3) and bismuth vanadate (BiVO4) as thin film n-photoanodes to complete the oxygen evolution half reaction for water splitting application in a tandem dual photosystem photoeletrocatalyic water splitting cell. These thin films are fabricated by low cost, robust, scalable, sol-gel dip coating methods and characterized by several techniques to verify the physical characteristics and photochemical performance. WO3 and BiVO4 are optimized by nanostructuration, interfacial surface modification, and addition of surface co-catalysts to increase performance and stability in acidic and neutral conditions, respectively. These materials are coupled with a copper (II) oxide p-photocathode to drive the hydrogen evolution reaction in a photoelectrocatalyic cell to complete the water splitting reaction. The photoelectrocatalytic cell constructed is inspired by previous literature reports encompassing an innovative tandem dual photosystem approach. As a result, this research reports one of the only entirely metal oxide based photoelectrocatalytic water splitting cells, fabricated by inexpensive, unexcessive techniques, resulting in a solar-to-hydrogen efficiency of 0.01% and an applied bias to photon efficiency of 0.06%.

Two main subjects are addressed in this study. The ability of a bright red material with metallic behaviour to be used as a visible light photocatalyst for hydrogen evolution and the feasibility of visible light photocatalytic water splitting using Z-schemes constituted from different kinds of photocatalysts and materials used as mediators. Strontium niobate (Sr₁₋ₓNbO₃) is an A-site deficient perovskite with intense red colour. It is an unusual material that displays both metallic type conduction and- as we present- photocatalytic activity. Specifically, photocatalytic visible light hydrogen production with oxalic acid as a sacrificial reagent is achieved from this material even without the need for a co-catalyst or other alteration. This photocatalytic activity is screened with time and related to different parameters that might influence it, like crystal structure, surface area and surface chemistry. The crystal structure of strontium niobate is A site stoichiometry dependant and the materials acquires a cubic symmetry for Sr≤ 0.92 and orthorhombic for 0.92≤ Sr≤ 0.97. The change of crystal structure from cubic to orthorhombic symmetry seems to have a negative effect on the photocatalytic activity, as the NbO₆ octahedra become distorted and unfavourable for d-orbital overlapping. The highest photocatalytic activity is exhibited at the turning point of one structure to the other. Increase in the photocatalytic activity is also exhibited by enlarging the surface area through ball milling, nevertheless, a clear trend for surface area effect on activity is not obtained among samples with different Sr content. Additionally, an enrichment of Sr on the surface of strontium niobate is observed by XPS, which apart from the fact that seems to be a governing factor improving stability it is also considered a key point for the exhibited photocatalytic activity altogether. Full water splitting under visible light from Z-schemes is studied by fabricating three general categories of systems. These three different categories depend on the mediator used to fabricate the Z-schemes and are: redox couple Z-schemes (with Fe⁺³/Fe⁺²), solid mediator Z-schemes (with GO) and no mediator Z-schemes. The materials used as photocatalysts for the fabrication of the Z-schemes are: Sr₀.₉₂NbO₃ for hydrogen production and both WO₃ and BiVO₄ independently for oxygen production. The photocatalytic activity for water splitting is evaluated in production of hydrogen and oxygen with time and the ratio of their production rates is frequently checked to see whether the ideal hydrogen to oxygen 2:1 is achieved. The general idea acquired from the results of all the three types of systems is that, water splitting with Z-schemes is a complicated process and in most cases governed by many subreactions. More specifically, in all cases of redox couple Z-schemes we got hydrogen to oxygen ratio imbalances and with the most prominent one being the lack of hydrogen production. Thankful is the fact that a certain type of system, the one consisting of WO₃ as oxygen photocatalyst and Fe⁺² as initial mediator species gives results very close to the ideal one and with a high degree of reproducibility indicating this way the probable formation of a Z-scheme that has overcome more of the imbalances. In between the two other categories, solid mediator and no mediator Z-schemes, subreactions seem to be the governing factor hence imbalances are always present. A case study in the no mediator Z-schemes on an attempt to investigate sources of imbalances, reveals that a big source of imbalance is most probably from the trapping of protons from WO₃.

El hidrógeno es un portador de energía que ya ha demostrado su capacidad para reemplazar el petróleo como combustible. Sin embargo, los medios de producción actualmente en uso siguen siendo altamente emisores de gases de efecto invernadero. La foto-electrólisis del agua es un proceso que, a partir de la energía solar, separa los compuestos elementales del agua como el hidrógeno y el oxígeno utilizando un semiconductor con propiedades físicas adecuadas. La hematita (¿-Fe2O3) es un material prometedor para esta aplicación debido a su estabilidad química y su capacidad para absorber una porción significativa de la luz (con una banda prohibida entre 2.0 - 2.2 eV). A pesar de estas propiedades ventajosas, existen limitaciones intrínsecas al uso de óxido de hierro para la descomposición fotoelectroquímica del agua. La primera restricción es la posición de su banda de conducción que es menor que el potencial de reducción de agua. Esta limitación se puede superar mediante la adición en serie de un segundo material, en tándem, que absorberá una parte complementaria del espectro solar y llevar a los electrones a un nivel de energía más alto que el potencial para la liberación de hidrógeno. El segundo obstáculo proviene del desacuerdo entre la corta longitud de difusión de los portadores de carga y la profundidad de penetración larga de la luz. Por lo tanto, es necesario controlar la morfología de los electrodos de hematita en una escala de tamaño similar a la longitud de transporte del orificio. En esta tesis, se introduce un nuevo concepto para mejorar el rendimiento fotoelectroquímico de la hematita. Usando el método hidrotermal depositamos capas delgadas de hematita dopada con Cr en sustratos de vidrio conductivo. También se ha preparado por medios electroquímicos una heterounión del tipo p-CuSCN/n-Fe2O3 depositando secuencialmente una capa de ¿-Fe2O3 y una película de CuSCNsobre sustratos de FTO (SnO2: F).Finalmente, se ha preparado células solares de perovskitas y óxido de hierro. Para ello se depositó una capa delgada, densa y uniformede óxido de hierro (¿-Fe2O3) como capa de transporte de electrones (ETL) en lugar de dióxido de titanio (TiO2) que se utiliza convencionalmente en las células fotovoltaicas perovskitastipoCH3NH3PbI3 (SGP). Este último dispositivo mostró un aumento en la fotocorriente del 20% y un IPCE30 veces mayor que la hematita simple, lo que sugiere una mejor conversión de las longitudes de onda por encima de 500 nm. Palabras clave: Fotoelectroquímica, división de agua, producción de hidrógeno, evolución de oxígeno, semiconductores de óxido de metal, hematita, óxido de hierro, nanoestructuras / Hydrogen is an energy carrier that has already demonstrated its ability to replace oil as a fuel. However, the means of production currently used remain highly emitting greenhouse gases. Photo-electrolysis of water is a process that uses solar energy to separate the elemental compounds of water such as hydrogen and oxygen using a semiconductor with adequate physical properties. Hematite (¿-Fe2O3) is a promising material for this application because of its chemical stability and ability to absorb a significant portion of light (with a band-gap between 2.0 - 2.2 eV). Despite these advantageous properties, there are intrinsic limitations to the use of iron oxide for the photoelectrochemical cracking of water. The first constraint is the position of its conduction band, which is lower than the water reduction potential. This constraint can be overcome by the addition in series of a second material, in tandem, which will absorb a complementary part of the solar spectrum and bring the electrons to a higher energy level than the potential of hydrogen release. The second obstacle comes from the disagreement between the short diffusion length of the charge carriers and the long light penetration depth. It is therefore necessary to control the morphology of the hematite electrodes on a scale of similar size to the transport length of the hole. In this thesis a new concept is introduced to improve the photoelectrochemical performances. Using the hydrothermal method we deposited thin layers of Cr-doped hematite on conductive glass substrates. We also electrochemically prepared a p-CuSCN / n-Fe2O3 heterojunction by sequentially depositing ¿-Fe2O3 and CuSCN films on FTO (SnO2: F) substrates. Finally, we have used uniform and dense thin layers of iron oxide (¿-Fe2O3) as an electron transport layer (ETL) in place of titanium dioxide (TiO2) conventionally used in photovoltaic cells based on perovskites CH3NH3PbI3 (PSC). This latter concept showed a 20% increase of the photocurrent and an IPCE 30 times greater than the simple hematite, suggesting better conversion of high wavelengths (> 500 nm). Keywords: Photoelectrochemistry, Water Splitting, Hydrogen Production, Oxygen Evolution, MetalOxide Semiconductors, Hematite, Iron Oxide, Nanostructures, Surface. / L'hidrogen és un proveïdor d'energia que ja ha demostrat la seva capacitat per reemplaçar el petroli com a combustible, però els mitjans de producció actuals continuen essent fortament emissors dels gasos responsables d'efecte hivernacle. La fotoelectròlisi de l'aigua és un procés que, a partir de l'energia solar, separa els compostos elementals d'aigua com l'hidrogen i l'oxigen utilitzant un semiconductor amb propietats físiques adequades. La hematita (¿-Fe2O3) és un material prometedor per a aquesta aplicació a causa de la seva estabilitat química i capacitat d'absorbir una porció significativa de la llum (amb un gap entre 2,0 i 2,2 eV). Malgrat aquestes propietats avantatjoses, hi ha limitacions intrínseques per a l'ús d'òxid de ferro per a la descomposició fotoelectroquímica de l'aigua. La primera restricció és la posició de la seva banda de conducció que és inferior al potencial de reducció d'aigua. Aquesta limitació es pot superar mitjançant l'addició en sèrie d'un segon material, en tàndem, que absorbirà una part complementària de l'espectre solar i portar els electrons a un nivell d'energia més alt que el potencial per a l'alliberament d'hidrogen. El segon obstacle prové del desacord entre la curta durada de la difusió dels portadors de càrrega i la llarga profunditat de penetració de la llum. Per tant, és necessari controlar la morfologia dels elèctrodes d'hematita en una escala de mida similar a la longitud del forat del transport. En aquesta tesi, es presenta un nou concepte per millorar el rendiment fotoelectroquímic. Mitjançant el mètode hidrotermal es van dipositar capes primes de hematita Cr-doped sobre substrats de vidre conductor. També s'han preparat electroquímicamentheterounions de tipus p-CuSCN/n-Fe2O3 dipositant seqüencialment una capa de ¿-Fe2O3 i altra de CuSCN sobre substrats FTO (SnO2: F).Finalment, s'han produït cél·lules solars de perovskitesi óxid de ferro. Per això es va depositaruna capa prima,densai uniforme d'òxid de ferro (¿-Fe2O3) com a capa de transport d'electrons (ETL) en lloc de diòxid de titani (TiO2) que s'utilitza convencionalment en les cèl·lules fotovoltaiques de perovskita híbrida del tipus CH3NH3PbI3 (SGP). Aquest últim dispositiu va mostrar un augment del fotocorrent del 20% i una IPCE30 vegades superior a la hematita simple, la qual cosa suggereix una millor conversió a longitud d'ones per sobre de 500 nm. Paraules clau:Fotoelectroquímica, divisió d'aigua, producció d'hidrogen, evolució d'oxigen, semiconductors d'òxids metàl·lics, hematita, òxid de ferro, nanoestructures. / Bouhjar, F. (2018). Preparation et performance d'une cellule photocatalytique à base d'hématite pour la génération d'hydrogène [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/106345 / TESIS

Water splitting through photoelectrochemical reaction is widely regarded as a major method to generate H2 , a promising source of renewable energy to deal with the energy crisis faced up to human being. Efficient exploitation of visible light in practice of water splitting with pure TiO2 material, one of the most popular semiconductor material used for photoelectrochemical water splitting, is still challenging. One dimensional TiO2 nanotubes is highly desired with its less recombination with the short distance for charge carrier diffusion and light-scattering properties. This work is based on TiO2 NTPC electrode by the optimized two-step anodization method from our group. A highly crystalized p-type Cu2O layer was deposited by optimized pulse potentiostatic electrochemical deposition onto TiO2 nanotubes to enhance the visible light absorption of a pure p-type TiO2 substrate and to build a p-n junction at the interface to improve the PEC performance. However, because of the real photocurrent of Cu2O is far away from its theoretical limit and also poor stability in the aqueous environment, a design of rGO medium layer was added between TiO2 nanotube and Cu2O layer to enhance the photogenerated electrons and holes separation, extend charge carrier diffusion length (in comparison with those of conventional pure TiO2 or Cu2O materials) which could significantly increase photocurrent to 0.65 mA/cm2 under visible light illumination (>420 nm) and also largely improve the stability of Cu2O layer, finally lead to an enhancement of water splitting performance.

Tin disulfide (SnS2) is a two-dimensional (2D) material with excellent properties and high prospects for low-cost solutions to catalytic and optoelectronic applications. In this work, vertical nanoflakes of SnS2 have been synthesized using custom-designed close space sublimation (CSS) system and investigated for applications in photoelectrochemical (PEC) water oxidation and metal-semiconductor-metal (MSM) photodetector. For the PEC application, vertical SnS2 nanoflakes grown directly on transparent conductive substrates have been used as photoanodes, which produce record photocurrents of 4.5 mA cm−2 for oxidation of a sulfite hole scavenger and 2.6 mA cm−2 for water oxidation without any hole scavenger, both at 1.23 VRHE in neutral electrolyte under simulated AM1.5G sunlight, and stable photocurrents for iodide oxidation in acidic electrolyte. This remarkable performance has been attributed to three main reasons: (1) high intrinsic carrier mobility of 330 cm2 V−1 s−1 and long photoexcited carrier lifetime of 1.3 ns in the nanoflakes, (2) the nanoflake height that balances the competing requirements of light absorption and charge transport, and (3) the unique stepped morphology of these nanoflakes that improves photocurrent by exposing multiple edge sites in every nanoflake. In another application, these SnS2 nanoflakes have been used to enhance the performance of lead sulfide quantum dot (PbS QDs) photodetectors by providing a high-mobility channel for photoexcited charges from PbS QDs, which results in 2 orders of magnitude enhancement in responsivity. The physical models and experimental findings presented in this dissertation can help engineer more cost-effective solutions for PEC water splitting and optoelectronics based on 2D metal dichalcogenides.

This thesis comprises an assessment of a novel concept to produce high purity hydrogen using mixed oxide ion/electronic conductor (MIEC) membranes and energy provided by solar concentrators (i.e. parabolic troughs or parabolic dishes). The vision of this concept is that it will be used to produce tons of high purity hydrogen for fuel cells, which is a scarce commodity with an increasing demand from residential and transportation power generation applications. The MIEC membrane activates a steam reforming reaction between water and methane to produce hydrogen of high purity on the water side and syngas on the fuel side. Expectations are that this concept has cost advantages over other thermo-chemical water-dissociation methods, using a lower temperature and no electricity for the reaction process. The thesis’ focus is on techno-economic aspects of the concept, as part of an application process for project financing by the European Commission of Research and Innovation. The assessment in the thesis shows that the overall efficiency of the concept is expected to be very low. It also identifies the difficulties of providing stable working conditions for the concept. Suggestions to improve the concept are proposed to address the most urgent problems of the concept. These suggestions illuminate the opportunities that actually do exist to combine MIEC membranes, solar energy and thermo-chemical water splitting into a working concept. These improvements include using parabolic dishes instead of parabolic troughs, using furnaces with control systems and using a viable flow rate. The production capacity of high purity hydrogen is expected to be approximately 89 mg per minute in a membrane bundle (i.e. 150 thin membrane fibers with an oxygen permeation flux of 1 ml cm-2 min-1) if these improvements were implemented. This would imply that the studied concept needs further development to produce high purity hydrogen in quantities that could meet the shortage on the commercial fuel cell markets.

This thesis concerns the development and the study of Iron-based water oxidation catalysts (WOCs) and how to immobilize them onto the hydrophobic surface of a carbon paste electrode. In the introductory chapter a general background of the field of water splitting and this thesis is given. In the second chapter, experimental performance is described from synthesis to measurements of a complete complex-doped electrode. The third chapter deals with the results and the discussion of the performed experiments. In chapter four, a descriptive conclusion of the obtained data is held. / Det här arbetet berör studien och utvecklingen utav järnbaserade katalysatorer, speciellt framtagna för för delning utav vatten. Utöver detta undersöks även om dessa katalysatorer (WOCs) kan immobiliseras på den hydrofoba ytan hos elektroder gjorda på kol-pasta. I det inledande kapitlet ges en generell bakgrund till området som berör delning utav vatten. I det andra kapitlet presenteras det experimentella utförandet utav synteser samt elektrokemiska mätningar som berörts under arbetets gång i jakten på en komplexdopad elektrod. I det tredje kapitlet diskuteras resultaten från mätningarna samt möjliga framtidsutsikter. I det fjärde kapitlet presenteras slutsatserna utav studien.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23216号 / 工博第4860号 / 新制||工||1759(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 阿部 竜, 教授 陰山 洋, 教授 藤田 晃司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM