Transition metal oxides for photoelectrochemical water-splitting and superconductivity
Abstract/Contents
- Abstract
- Transition metal oxide materials have garnered significant research interest over the past decades due to their diverse chemical and physical properties, ranging from electrochemistry and superconductivity. Moreover, the capability to access vastly different properties with similar crystal structures by controlling the stoichiometry provides a powerful additional degree of freedom in materials engineering for applications. By using pulsed laser deposition, we obtained epitaxial thin films providing a solid platform to investigate and engineer the properties of these oxides. We will first discuss a transition metal oxide, known as pseudobrookite (Fe2TiO5), for photoelectrochemical (PEC) water-splitting. Recently, Fe2TiO5 has emerged as a photoanode for water oxidation due to its chemical stability, scalability, and suitable bandgap. Based on our successful fabrication of epitaxial thin films, we will present our comprehensive characterization of the intrinsic PEC properties. We discovered that Fe2TiO5 exhibits highly efficient charge transfer at the Fe2TiO5-electrolyte interface and deduce a long minority carrier diffusion length of 19 nm, far exceeding that of α-Fe2O3. Furthermore, by forming heterostructures, PEC performance of α-Fe2O3 is enhanced significantly, where photocurrent density increases by one order of magnitude, and the onset potential improves by ∼300 mV. In the second topic, we discuss the infinite layer nickelates, RENiO2 (RE: rare-earth element). Ever since their discovery, superconductivity in cuprates has motivated the search for materials with analogous electronic or atomic structure. Here we present how soft chemistry approaches can be used to synthesize superconducting infinite layer nickelates from their perovskite precursor phase, using topotactic reactions. Following the discovery of superconductivity in Nd1−xSrxNiO2, we find superconductivity in Pr1−xSrxNiO2 and La1−xSrxNiO2.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2020; ©2020 |
| Publication date | 2020; 2020 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Osada, Motoki |
|---|---|
| Degree supervisor | Dauskardt, R. H. (Reinhold H.) |
| Degree supervisor | Hwang, Harold Yoonsung, 1970- |
| Thesis advisor | Dauskardt, R. H. (Reinhold H.) |
| Thesis advisor | Hwang, Harold Yoonsung, 1970- |
| Thesis advisor | Cui, Yi, 1976- |
| Degree committee member | Cui, Yi, 1976- |
| Associated with | Stanford University, Department of Materials Science and Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Motoki Osada. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2020. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2020 by Motoki Osada
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
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