자료유형 | 학위논문 |
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서명/저자사항 | Solar Fuel Synthesis via Photoelectrochemistry: Understanding and Controlling Interfaces. |
개인저자 | He, Yumin. |
단체저자명 | Boston College. GSAS - Chemistry. |
발행사항 | [S.l.]: Boston College., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 178 p. |
기본자료 저록 | Dissertations Abstracts International 81-04B. Dissertation Abstract International |
ISBN | 9781085677974 |
학위논문주기 | Thesis (Ph.D.)--Boston College, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
Advisor: Mohanty, Udayan. |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | Solar fuel synthesis via photoelectrochemistry represents a promising strategy to achieve solar energy conversion and storage. The improvement of photoelectrochemical water splitting performance lies in choosing suitable photoelectrode materials, followed by strategic optimization of their properties. Among those properties, the interface between the semiconductors and electrolyte is of paramount importance, yet it is still not well understood. In my dissertation, I will mainly focus on understanding and controlling those interfaces, with two study platforms.The first study platform is tantalum nitride (Ta3N5), which is an attractive photoanode material with good optoelectronic properties. However, it suffers from low photovoltage despite of the high theoretical expectation and rapid performance decay when it is used for water oxidation. With the help of various characterization methods, it was found that water or hydroxyl group adsorption on the surface as well as the self-limited surface oxidation during water oxidation led to the positive shift of band edge positions and Fermi level, accompanied with increase of charge transfer resistance on the surface. In consequence, decrease of photovoltage and photocurrent was observed.Two different strategies were developed. The first was to fully isolate Ta3N5 from water with the deposition of uniform protection layer through atomic layer deposition. The second strategy utilized the reaction between Ta3N5 and co-catalyst instead of water, which led to the formation of a photo-induced interface that favored the desired chemistry instead of side reactions.The second study platform is a Si buried junction protected by GaN. By tuning the loading amount of Pt nanoparticles on GaN surface, both the photocurrent density and photovoltage of the photocathode was improved. With detailed spectroscopic study, it was implied that both charge transfer kinetics and interfacial energetics could be influenced by the loading of Pt on the surface. |
일반주제명 | Chemistry. Physical chemistry. |
언어 | 영어 |
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