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New abundant 4CzIPN-derivatized Photosensitizers and Catalysts for Photosynthetic Organic Reactions and Solar Fuels
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- Author / Creator
- Martinez Perez, Octavio
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The development of artificial photosynthetic systems is a promising strategy to meet future energy demands of our society and to reverse the impact of anthropogenic CO2 in the environment. Energy conversion devices such as photoelectrochemical cells are one key component in the transition to a society with an integrated renewable energy system. This research describes a robust, high-yield route for the synthesis, characterization, and catalytic activity of photocatalysts for artificial photosynthesis, as well as a solid-state synthesis method to prepare stable and efficient photocatalyst-semiconductor electrodes.To facilitate the integration of the photocatalytic systems to the electrical grid, the molecular assembly of these Ru-photosensitizers to photocatalytic water oxidation (OER) or carbon dioxide reduction reaction (CRR) catalysts with further immobilization onto semiconductor surfaces is a highly desirable achievement. Here, Ru-polypyridyl photosensitizers are immobilized on semiconductor surfaces (ITO and TiO2 ) via diazonium reduction, forming a C—O bond between the C5 on the 1,10-Phenanthroline ligand and the O on the surface. The photosensitizer-semiconductor photoelectrodes are active and stable toward the photoelectrochemical oxidation of hydroquinone (H2 Q) and triethylamine (Et3 N) under neutral and basic conditions.The organic photosensitizer 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) and its derivatives are well-known photocatalysts for visible-light-driven photoredox- and energy transfer-catalysis. Here, is described the derivatization of the dicyanobenzene moiety in 4CzIPN with an NHC group: 3CzIPN-NHC. 3 NHC ligands are well-known as strongly activating ligands in catalysis. 3CzIPN-NHC retains the bulk photophysical properties of the parent 4CzIPN photosensitizer. This synthesis opens a window for future tuning of the photosensitizer and incorporation into heterogeneous and homogenous photocatalysis.The synthesis and photocatalytic activity of the Mn (I) [Mn(CO)3 (bpy)] catalyst coupled to an organic photosensitizer unit derived from 4CzIPN, the 3-CzIPN-imidazole is presented. The complex 3CzIPN-Imidazole-Mn is highly selective for the photoreduction of CO 2 to CO in CO2a–saturated acetonitrile (MeCN) solution under AM 1.5 G light. Achieving 60 TON (CO), the facile, robust, and low-cost preparation, in addition to strong absorption in the visible light range, promotes this photocatalyst as a potent candidate for further family expansion.
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- Graduation date
- Spring 2024
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.