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在CdS纳米-[FeFe]-酶复合体中的电子转移动力学以及对光化学H2生成的含义
Molly B Wilker1, Katherine E Shinopoulos, Katherine A Brown
1Department of Chemistry and Biochemistry, University of Colorado Boulder , Boulder, Colorado 80309, United States.
Journal of the American Chemical Society
|February 26, 2014
概括
研究了硫化纳米棒 (CdS NR) 和[FeFe]-酶I (CaI) 之间的电子转移动力学. 类似的电子转移和放松率在CdS NRs中限制了H2生产效率,建议进行结构修改以改进.
科学领域:
- 生物物理化学 生物物理化学
- 纳米材料科学 科学 纳米材料科学
- 光催化作用的光催化
背景情况:
- 使用复杂的硫化纳米棒 (CdS NRs) 和[FeFe]-酶I (CaI) 的光化学生产H2显示了高达20%的量子产量与电子供体.
- 从CdS NRs到CaI的电子转移 (ET) 动力学对于整体光化学反应性至关重要,因为ET量子效率决定了最大的H2生成产量.
研究的目的:
- 调查CdS NR中ET和电子放松通路之间的竞争.
- 直接测量ET的速率和量子效率,从光激发的CdS NRs到CaI.
- 了解CdS-CaI复合体中电子注入和传输的机制.
主要方法:
- 暂时吸收光谱法被用来直接测量ET动力学.
- 这项研究使用了来自Clostridium acetobutylicum的光激发的CdSNR和[FeFe]-酶I (CaI).
- 实验包括使用催化活性和非活性形式的.
主要成果:
- 在CdS NR中,电子转移速率常数 (k(ET)) 和电子放松速率常数 (k(CdS)) 发现是可比的,两者都在10(7) s(-1).
- 对于CaI:CdS NR复合物,ET的量子效率被确定为42%的,其摩尔比为1:1.
- 观察到电子注入发生在远端铁硫集群,然后通过辅助集群传输到活性部位,不论CaI的催化活性.
结论:
- 在CdS NR中ET和电子放松的可比率对H2生产效率构成瓶.
- 通过纳米晶体结构修改,可以通过增加k(ET) 和/或减少k(CdS) 来提高H2生产效率.
- 这些发现提供了关于CdS-CaI复合体中光化学H2生成的动态通路及其与整体效率的关系的见解.
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