氧空位占用对BiVO4光电极载体动态的影响
Shababa Selim1, Ernest Pastor1, Miguel García-Tecedor2
1Department of Chemistry and Centre for Plastic Electronics, MSRH, White City Campus , Imperial College London , London W12 0BZ , United Kingdom.
Journal of the American Chemical Society
|October 31, 2019
概括
在BiVO4光电极中的氧气空缺是性能的关键. 这项研究确定了它们的光谱特征,并展示了它们的电离影响如何改善光电化学应用的电荷载体动力学.
科学领域:
- 材料科学
- 摄影化学
- 电化学
背景情况:
- 氧气空隙在金属氧化物中至关重要,它会影响电荷载体的动态.
- 它们在光电化学 (PEC) 和光催化应用中的确切作用尚未得到充分理解和讨论.
- 识别氧空状态的光谱指纹是必不可少的.
研究的目的:
- 调查BiVO4光阳极中氧气空位的电子占用和功能.
- 为了确定氧气空位电离的明确的光谱特征.
- 阐明氧气空缺对电荷载体动态和PEC性能的影响.
主要方法:
- 在现场调节氧空状态的电子占用.
- 使用五种互补的光谱技术.
- 对电离和电子脱落动力学的激活能量分析.
主要成果:
- 确定了氧气空位电离的特定光谱特征.
- 为这种电离过程确定了约0.2 eV的激活能量.
- 证明热激活的电子脱落从电离状态控制了电子提取动力学.
- 显示大量的非电离状态作为深孔陷, 阻碍水氧化.
结论:
- 提供了对BiVO4光电极中氧气空位的功能的清晰洞察.
- 解决了有关氧气空缺在PEC表现中的作用的争议.
- 强调电离氧空置状态对于有效的电荷载体提取和在较高温度下提高PEC性能的重要性.
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