京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19737号 / 工博第4192号 / 新制||工||1646(附属図書館) / 32773 / 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 田中 庸裕 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19740号 / 工博第4195号 / 新制||工||1647(附属図書館) / 32776 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 田中 庸裕, 教授 阿部 竜, 教授 陰山 洋 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第21178号 / 人博第850号 / 新制||人||203(附属図書館) / 29||人博||850(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 吉田 寿雄, 教授 内本 喜晴, 教授 田部 勢津久 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21789号 / 工博第4606号 / 新制||工||1717(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 田中 庸裕, 教授 佐藤 啓文, 教授 阿部 竜 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

No description available.

As an important part of the periodic table, metal elements have attracted widespread attention due to their special physical and chemical properties, as well as effective functionalities. Many metals at the nanoscale level exhibit a wide array of applications, ranging from catalysis to photonics, electronics, energy conversion/storage, and medicine. To obtain a more effective functionality in application, it is indispensable to synthesize uniform metal nanoparticles with well-defined size, morphology, composition, and crystal structures. In this dissertation, we will demonstrate high-boiling point solvent method for synthesizing metal nanocrystals, ranging from single metal nanocrystals (e.g., iridium (Ir), ruthenium (Ru), germanium (Ge), bismuth (Bi)) to binary metal nanocrystals (e.g., Sn-Ge), and ternary intermetallic compounds (e.g., Pt1-xPdxBi). By varying different halogen ions, we can get different morphologies of metal nanocrystals. We will further study the catalytic effect of Pd metal nanocrystals supported on silicon spheres and realize the hydrodeoxygenation reaction of vanillin under mild conditions.First, we used bismuth as an example to study the shape-controlled synthesis of metal nanocrystals by adjusting the injection temperature and the added halide ions (e.g., Cl-, Br-). Our findings indicated that due to the different electronegativities, halide ions are selectively adsorbed on specific crystal planes during the growth of Bi NCs, leading to different morphologies. Then we proposed a tungsten hexacarbonyl (W(CO)6)-assisted reduction strategy for obtaining uniform metal nanoparticles (e.g., Ir, Ru, Ge, Bi) of different metal salts. This strategy was extended to the synthesis of uniform binary metal (e.g., Sn-Ge) nanoparticles, which we can get tunable bandgap (0.51 eV to 0.72 eV) based on the controlled reaction of Ge2+ precursor solution with uniform tin (Sn) nanocrystals (NCs) as the template. Next, we realized the synthesis of intermetallic Pt1-xPdxBi nanoplates with controllable compositions, including Pt0.5Pb0.5Bi, Pt0.25Pd0.75Bi, and Pt0.75Pd0.25Bi via the sequential complexation-reduction-sorting method. Furthermore, we used palladium (Pd) metal nanoparticles (NPs) as a photocatalyst to trigger the hydrodeoxygenation reaction of vanillin. We demonstrated a model to disperse free-standing Pd NP on dielectric silica nanospheres (SiOx NSs). The spherical shape of SiOx can cause scattering resonance, thereby enhancing the local electric field on or near the surface to enhance light absorption of Pd NPs, further realizing a more effective catalyze on chemical reactions. We found that the adsorption of H2 on Pd is too strong to support the reaction effectively, but light absorption can reduce the "poisoning effect" by weakening the adsorption of hydrogen on Pd surface. Overall, we use innovative strategies to effectively synthesize a variety of high-quality metal nanomaterials. Our work shows that the Pd-NP/SiOx-NS composite nanostructure using dielectric SiOx as an optical nanoantenna is a promising photocatalyst that can drive photonic chemical conversion with high efficiency. / Chemistry

La tesis doctoral describe estrategias útiles y sencillas para las síntesis de 2-oxindoles 3,3'-disustituídos y alcoholes homoalílicos. La memoria se divide en dos grandes bloques: el primero referido a la alquilación desacilativa como método para la síntesis de 2-oxindoles 3,3'-disustituídos que engloba la introducción I, el capítulo I titulado alquilación desacilativa para la síntesis de 2-oxindoles 3,3'-disustituídos y capítulo II titulado bromación desacilativa para la síntesis de 3,3'-bioxindoles y aislamiento de 3-bromooxindoles. La segunda parte se refiere a fotocatálisis y metalofotocatálisis como nuevos métodos de síntesis orgánica y engloba la introducción II, capítulo III titulado fotocatálisis para la síntesis de 3,3'-bioxindoles y capítulo IV titulado catálisis dual para la alilación de aldehídos.

This thesis documents efforts to synthesize Metal-Organic Frameworks (MOFs) and study their charge transport, electrocatalytic, and photoredox catalytic properties. Chapter 1 introduces concepts of pre-synthetic and post-synthetic metalation of MOFs. A series of four chemically identical but structurally different hydrolytically robust ZrIV-MOFs constructed from tetrakis(4-carboxyphenyl) porphyrinato iron (III) are examined to understand the influence of topological construction on redox hopping conductivity. The structural variation fixes center-to-center distances in the four MOFs and defines the hopping rate. The spin-state variation of the central metal in the porphyrin unit helps in further tuning the TCPP(FeIII/II) reorganization energy of the self-exchange process. The hopping rate significantly increased upon axial coordination of 1-methyl imidazole to the iron center, which converts a weakly halide bound five-coordinated high-spin (HS) TCPP(FeIII/II) to the six-coordinated low-spin (LS) complex. The population of LS vs HS species is shown to be a function of topology in the presence of an excess ligand. Chapter 2 investigates this idea further by using MOFs for electrocatalytic oxygen reduction reaction (ORR). Two cobalt-centered porphyrin-based MOFs are synthesized and deposited on various substrates to afford working electrodes that can be used in an electrochemical cell to catalyze the ORR. Chapter 3 investigates the linker-dependent photoredox catalytic activity of MOFs that possess the same topology. This is the first MOF-based study wherein a heavy metal like ruthenium is not employed to carry out the visible light-dependent photoredox catalysis.

Magister Scientiae - MSc (Chemistry) / Drinking water with high concentrations of inorganic and organic contaminants can cause adverse health defects. Specifically methyl orange dye is an organic water contaminant that has been known (along with others like methyl blue etc.) to have an increase in our water systems over the past few years due to increasing demand in industrial processes. It is therefore of utmost importance to remediate organic contaminants and ultimately enable prevention. The contaminants can be removed by photocatalysis. Anatase TiO2 is known for its photocatalytic degradation of environmental pollutants and photoelectro-chemical conversion of solar energy. However its application is limited since it is a wide band gap semiconductor, (Eg = 3.2 eV). The following study deals with the enhancement of the photocatalytic properties of TiO2 for remediation of organic water contaminants.