Zhang Yiwei, de Aguiar Hilton B, Hynes James T, Laage Damien
PASTEUR, Department of Chemistry , École normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France.
Département de Physique , École normale supérieure, PSL University, CNRS , 24 rue Lhomond , 75005 Paris , France.
J Phys Chem Lett. 2020 Feb 6;11(3):624-631. doi: 10.1021/acs.jpclett.9b02924. Epub 2020 Jan 10.
The properties of water at an electrified graphene electrode are studied via classical molecular dynamics simulations with a constant potential approach. We show that the value of the applied electrode potential has dramatic effects on the structure and dynamics of interfacial water molecules. While a positive potential slows down the reorientational and translational dynamics of water, an increasing negative potential first accelerates the interfacial water dynamics before a deceleration at very large magnitude potential values. Further, our spectroscopic calculations indicate that the water rearrangements induced by electrified interfaces can be probed experimentally. In particular, the calculated water vibrational sum-frequency generation (SFG) spectra show that SFG specifically reports on the first two water layers at 0 V but that at larger magnitude applied potentials the resulting static field induces long-range contributions to the spectrum. Electrified graphene interfaces provide promising paradigm systems for comprehending both short- and long-range neighboring aqueous system impacts.
通过采用恒电位方法的经典分子动力学模拟，研究了带电石墨烯电极上的水的性质。我们表明，施加的电极电位值对界面水分子的结构和动力学有显著影响。当正电位减缓水的重排和平动动力学时，增加的负电位首先加速界面水动力学，然后在非常大的电位值时减速。此外，我们的光谱计算表明，带电界面引起的水重排可以通过实验探测。特别是，计算得到的水振动和频产生（SFG）光谱表明，SFG在0 V时专门报告前两层水，但在较大的施加电位时，产生的静电场会对光谱产生长程贡献。带电石墨烯界面为理解短程和长程相邻水体系的影响提供了有前景的范例系统。
