Thesis advisor: Udayan Mohanty / Among the existing strategies to direct solar energy harvesting and storage, solar fuel production by photoelectrocatalysis promises a comparatively simple, low-cost route. The science behind this process is straightforward: stable semiconductors absorb sunlight and use the energy to excite charges, which then drive redox reactions at the surface. Careful studies of the photoelectrode surface provide important considerations in building a high-performance photoelectrode. Specifically, I focused on controlling the surface band alignment of Cu2O photocathode|water for hydrogen evolution reaction. A ZnS buried heterojunction is formed to improve the photovoltage. Then I focused on understanding the influence of chemical species on surface kinetics and energetics for water oxidation reaction. Two hematite photoanodes with preferably exposed {001} and {012} facets were examined. Further, I systematically studied three different types of surfaces, bare hematite, hematite with a heterogenized Ir water oxidation catalyst (WOC), and a heterogeneous IrOx WOC. While both WOCs improve the performance of hematite by a large margin, their working mechanisms are found to be fundamentally different. I also focused on utilizing surface photoexcited species to control product selectivity. Selective CO production by photoelectrochemical methane oxidation is successfully demonstrated. Detailed experimental investigations revealed that a synergistic effect by adjacent Ti3+ sites is the key to CO formation. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
| Identifer | oai:union.ndltd.org:BOSTON/oai:dlib.bc.edu:bc-ir_108121 |
| Date | January 2018 |
| Creators | Li, Wei |
| Publisher | Boston College |
| Source Sets | Boston College |
| Language | English |
| Detected Language | English |
| Type | Text, thesis |
| Format | electronic, application/pdf |
| Rights | Copyright is held by the author, with all rights reserved, unless otherwise noted. |
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