Ultrafast Dynamics of Water Radiolysis: Hydrated Electron Formation, Solvation, Recombination, and Scavenging
Ultrafast Dynamics of Water Radiolysis: Hydrated Electron Formation, Solvation, Recombination, and Scavenging
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水辐射分解的超快动力学：水合电子的形成、溶剂化、复合和清除
DOI：
10.1021/acs.jpclett.0c01468
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
T. Suzuki
中科院分区：
文献类型：
--
作者：
Y. Yamamoto;T. Suzuki
利用飞秒时间分辨光电子能谱研究了真空紫外光激发液态水时水合电子的超快形成、溶剂化和成对复合以及NO3-的静态和动态清除过程。过量电子的溶剂化时间常数是典型的液态水，但略有增加，随着激发能的增加。由于以前未观察到的超快孪晶复合在5 ps的时间内的电子生存概率被发现是远低于文献值。NO3-诱导超快（静态）清除液态水的光激发电子态和动态清除脱离电子的反应速率，这是依赖于激发能。在7.7 eV的水合电子的形成归因于氢原子转移过程，但它是合理的，额外的形成通道在更高的能量打开。
The ultrafast formation, solvation, and geminate recombination of hydrated electrons upon vacuum ultraviolet photoexcitation of liquid water and the static and dynamic scavenging by NO3–are investigated using femtosecond time-resolved photoelectron spectroscopy. The solvation time constant for excess electrons is typical of that for liquid water but increases slightly with increasing excitation energy. The electron survival probability for geminate recombination is found to be much lower than the literature values owing to previously unobserved ultrafast geminate recombination in a period of 5 ps. NO3–induces the ultrafast (static) scavenging of photoexcited electronic states of liquid water and the dynamic scavenging of detached electrons with a reaction rate that is dependent on the excitation energy. The formation of hydrated electrons at 7.7 eV is ascribed to a H-atom-transfer process, but it is plausible that additional formation channels open at higher energies.