Résumé
The molecular structure of water has profound influence on electron transfer and redox processes at metal–water interfaces. While ab initio molecular dynamics simulations provide an accurate description of the interfacial structure, the respective computational cost is often prohibitive. Static simulations using a few ordered water layers can serve as a pragmatic alternative maintaining an explicit description of molecular interactions at an affordable computational cost. We here study the coupling between electronic and structural degrees of freedom at ferroelectrically ordered metal–water interfaces. With increasing number of ice-like water layers, we observe a long-range transfer of electrons between the metal’s Fermi level and HOMO/LUMO states of the outermost water molecules, mediated by ordered solvent dipole layers. Our findings reveal limitations of the applicability of the ordered interface model and reveal a strong coupling between ferroelectric ordering and long-range (auto)redox phenomena at dipolar solvent structures, shedding new light onto the long-standing question on the existence and stability of ferroelectric ice. Implications for the activation of water molecules in electrocatalytic reactions at charged metal–water interfaces are suggested.