Electrolytes Change the Interfacial Water Structure but not the Vibrational Dynamics.
Electrolytes Change the Interfacial Water Structure but not the Vibrational Dynamics.
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DOI：
10.1021/acs.jpcb.9b08131
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发表时间：
2019-09
期刊：
影响因子：
--
通讯作者：
M. Deiseroth;M. Bonn;E. Backus
中科院分区：
文献类型：
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作者：
M. Deiseroth;M. Bonn;E. Backus
气溶胶上发生的非均相臭氧化学是由界面化学驱动的，因此受到气溶胶颗粒表面状态的影响。因此，电解质对界面水结构的影响一直在深入研究。然而，界面处的能量耗散率和机制的后果很大程度上未知。在这里，我们使用时间分辨和频发生光谱法揭示了纯水-空气的弛豫路径与 Na2SO4 和 Na2CO3 水溶液的相同，尽管界面水结构发生了很大的改变。我们进一步表明，从所有研究的系统中提取了相似的寿命，并且这些寿命显示出从 0.2 ps 到 1 ps 的激发频率相关弛豫时间。因此，尽管相同系统上的静态 SFG 表明添加电解质时界面水结构发生变化，但纯水和不同电解质溶液的动力学是无法区分的。
Heterogeneous ozone chemistry occurring on aerosols is driven by interfacial chem- istry and thus affected by the surface state of aerosol particles. Therefore, the effect of electrolytes on the structure of interfacial water has been under intensive investi- gation. However, consequences for energy dissipation rates and mechanisms at the interface are largely unknown. Here, we use time-resolved sum frequency generation spectroscopy to reveal that the relaxation pathway is the same for neat water-air as for aqueous solutions of Na2SO4 and Na2CO3 , although the interfacial aqueous structure is substantially modified. We further show that similar lifetimes are extracted from all investigated systems and that these lifetimes show an excitation frequency dependent relaxation time from 0.2 ps up to 1 ps. Hence, despite static SFG on the same systems revealing that the interfacial aqueous structure changes upon adding electrolytes, the dynamics are indistinguishable for both pure water and different electrolyte solutions.