Influence of ionic species on water broadband electrodynamics

Proton exchange plays a central role in modern electrochemical systems. While it is well described for times larger than milliseconds [1], it is an important process not fully understood on nanoscale distances and subpicosecond timescales. Here, we discuss the dynamical structure of water from femtoseconds to seconds time intervals using a combination of broadband dielectric spectroscopy and infrared spectroscopy methods. Accounting for dielectric properties [2], isotopic effects [3] and confinement effects [4], we present a model of water based on the time-dependence of the ionic species concentration, over the whole time interval between the intermolecular direct current (below microseconds) and intramolecular infrared vibrations (sub-picoseconds), which so far was hardly achievable. Our approach provides a new vision on the hydrogen bonding in water taking into account the role of ionic species on the intermolecular interactions; and we discuss how this paves the way to innovative design of electrochemical energy storage devices.

[1] R. P. Bell, Proton in chemistry (Cornell University Press, 1959).
[2] V. G. Artemov, Phys. Chem. Chem. Phys. 21, 8067 (2019).
[3] V. G. Artemov, et. al, arXiv:1910.07578 (2019).
[4] H. Ouerdane et al., J. Phys. Chem. C 114, 12667 (2010).