纳米结构的三氧化物光电极中的水氧化和电子提取动力学
Sacha Corby1, Laia Francàs1, Shababa Selim1
1The Department of Chemistry , Imperial College London , South Kensington, London SW7 2AZ , U.K.
Journal of the American Chemical Society
|November 2, 2018
概括
了解三氧化物 (WO3) 光电极动力学对于高效的水氧化是至关重要的. 与其他金属氧化物不同,WO3的氧化速度比电子提取更快,从而最大限度地减少了重组损失.
科学领域:
- 材料科学
- 光催化
- 电化学
背景情况:
- 有效的氧化水是可再生能源技术的关键.
- 过渡金属氧化物是有前途的光电极材料,但它们的效率受到重组的限制.
- 了解反应动力学对于优化光电极性能至关重要.
研究的目的:
- 在三氧化物 (WO3) 光电极中研究水氧化和电子提取之间的动力竞争.
- 将这些动力学与表面重组和整体水氧化效率相关联.
- 阐明氧空位在电子提取动力学中的作用.
主要方法:
- 短暂的扩散反射光谱检测反应动力学.
- 短暂的光电流测量以评估电子提取.
- 根据不同应用偏差和薄膜处理来调节氧空密度的研究.
主要成果:
- 三氧化物 (WO3) 呈现出比电子提取 (∼10毫秒) 更快的水氧化动力.
- 在WO3中,电子提取速度比其他金属氧化物 (例如TiO2,α-Fe2O3,BiVO4) 慢,并且与氧空位的电子捕获有关.
- 尽管电子提取速度缓慢,但WO3显示了适度的电荷重组损失和近平带的光电开始潜力.
结论:
- WO3的快速氧化动力学归因于其氧化价值带,超过了表面重组.
- 在WO3中氧气空缺会产生浅陷状态,减缓电子提取,但不会显著增加重组.
- WO3的独特动力特征凸显了热力学驱动力在光催化中对高效的水氧化的重要性.
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